Macroevolution

The observations to be recorded in this Paper were commenced in March, 1905. They originated in an attempt to find a general method for rearing marine larval forms. Several investigators had previously succeeded in rearing Echinoderms, Molluscs, and Polychætes from artificially fertilized eggs under laboratory conditions, but the process was generally difficult and the results more or less uncertain. The most promising method seemed to be that adopted by Caswell Grave (26), who was able to rear his larvæ by feeding them on diatoms. Grave obtained his diatoms by placing sand, collected from the sea bottom, in aquaria and using such diatoms as developed from this material. All the methods, however, suffered from the uncertainty of not knowing what organisms were introduced into the aquaria in which the larvse were to be reared, either in the original sea-water or along with the food-supply.

@article{doi101017s0025315400073690,
    author = "Allen, E. J. and Nelson, Edward William",
    title = "On the Artificial Culture of Marine Plankton Organisms",
    year = "1910",
    journal = "Journal of the Marine Biological Association of the United Kingdom",
    abstract = "The observations to be recorded in this Paper were commenced in March, 1905. They originated in an attempt to find a general method for rearing marine larval forms. Several investigators had previously succeeded in rearing Echinoderms, Molluscs, and Polychætes from artificially fertilized eggs under laboratory conditions, but the process was generally difficult and the results more or less uncertain. The most promising method seemed to be that adopted by Caswell Grave (26), who was able to rear his larvæ by feeding them on diatoms. Grave obtained his diatoms by placing sand, collected from the sea bottom, in aquaria and using such diatoms as developed from this material. All the methods, however, suffered from the uncertainty of not knowing what organisms were introduced into the aquaria in which the larvse were to be reared, either in the original sea-water or along with the food-supply.",
    url = "https://doi.org/10.1017/s0025315400073690",
    doi = "10.1017/s0025315400073690",
    openalex = "W1989219206"
}

Summary 1. In analysing the ecological conditions of an animal population we have above all to focus our attention upon the most sensitive stages within the life cycle of the animal, that is, the period of breeding and larval development. 2. Most animal populations on the sea bottom maintain the qualitatively composition of the species composing them, over long periods of time, though the individual species use quite different modes of reproduction and development. This shows that species producing a large number of eggs have a larger wastage of eggs and larvae than those with only a few eggs. The wastage of eggs in the sea is much larger than on the land and in fresh water. 3. In the invertebrate populations on the level sea bottom, large fluctuations in numbers from year to year indicate species with a long pelagic larval life, while a more or less constant occurrence indicates species with a very short pelagic life or a non‐pelagic development. 4. In most marine invertebrates which shed their eggs and sperm freely in the water, either (a) the males are the first to spawn, thus stimulating the females to shed their eggs, or (b) an ‘epidemic spawning’ of a whole population takes place within a few hours. Both methods greatly favour the possibility of fertilization of the eggs spawned and show that the heavy wastage of eggs and larvae takes place after fertilization, during the free swimming pelagic life. 5. Embryos with a non‐pelagic development may originate (a) from large yolky eggs, in which case all the hatching young of the same species will be at the same stage of development, or (b) from small eggs which during their development feed on nurse eggs, when the individual embryos of the same species may vary enormously in size at the stage of hatching. 6. Three types of pelagic larvae are known: (a) Lecithotrophic larvae, originating from large yolky eggs spawned in small numbers by the individual mother animals; they are independent of the plankton as a source of food although growing during pelagic life, are absent from high arctic seas but constitute about 1 o % of the species with pelagic larvae in all other seas, (b) The planktotrophic larvae with a long pelagic life, originating from small eggs spawned in huge numbers by the individual mother animal; they feed from, and grow in, the plankton, constituting less than 5% of high arctic bottom invertebrates, 55–65% of the species in boreal seas, and 8 o ‐85 % of the tropical species, (c) The planktotrophic larvae with a short pelagic life having the same size and organization at the moment of hatching and at the moment of settling; these constitute about 5% of the species in all Recent seas. 7. To find out the factors which cause the enormous waste of eggs and larvae, we thus have to study those forms (constituting 7 o % of all species of bottom invertebrates in Recent seas) which have a long planktotrophic pelagic life, as only species reproducing in this way have really large numbers of eggs. 8. The food requirements of the planktotrophic pelagic larvae are much greater than those of the adult animals at the bottom. The adaptability of the larvae to poor food conditions seems, nevertheless, to be greater than hitherto believed. The significance of starvation seems mainly to be an indirect one: poor food conditions cause slow growth, prolong larval life, and give the enemies a longer interval of time to attack and eat the larvae. 9. At the temperatures to which they are normally exposed, northern as well as tropical larvae seem on an average to spend a similar time (about 3 weeks) in the plankton. The length of the pelagic life of the individual species may, however, vary significantly in nature. In the Sound (Denmark) the larvae are never exposed to temperatures outside the range which they are able to endure. The wastage caused by temperature, like that due to starvation, seems mainly to be an indirect one: low temperatures postpone growth and metamorphosis, and give the enemies a longer time to feed on the larvae. 1 o. When a larva feeding on a pure algal diet metamorphoses into a carnivorous bottom stage, a ‘physiological revolution’ occurs and a huge waste of larvae might be expected. Experiments have, however, shown that this is not the case. 11. Young pelagic larvae are photopositive and crowd near the surface; larvae about to metamorphose are photonegative. Larval polychaetes, echinoderms, and presumably also prosobranchs, may prolong their pelagic life for days or weeks until they find a suitable substratum. Forced towards the bottom by their photonegativity and transported by currents over wide bottom areas, testing the substratum at intervals, their chance of finding a suitable place for settling is much better than hitherto believed. 12. Continuous currents from the continental shelf towards the open ocean may transport larvae from the coast to the deep sea where they will perish. Such conditions may (for instance in the Gulf of Guinea) deeply influence the composition of the fauna, while in other areas (European western coast, southern California) they seem to be only of small significance. 13. The toll levied by enemies appears to be the most essential source of waste among the larvae. A list of such enemies, comprising other pelagic larvae, holoplank‐tonic animals and bottom animals, is given on p. 2 o. A medium‐sized Mytilus edulis, filtering 1–4 1. of water per hour, may retain and kill about 100,000 pelagic lamellibranch larvae in 24 hr. during the maximum breeding season in a Danish fjord. 14. Species reproducing in a vegetative way, by fission, laceration, budding, etc., might be expected to have good chances of competition in such areas where conditions for sexual reproduction are unfavourable. Nevertheless, they only supply a rather small percentage of the animal populations of all Recent seas, probably because their intensity of reproduction is low and because they are unable to spread to new areas. Most forms reproducing in a vegetative way have sexual reproduction as well. 15. Pelagic development is nearly or totally suspended in the deep sea, and is restricted to the shelf faunas. In the arctic and antarctic seas pelagic development is nearly or totally suppressed, even in the shelf faunas, but starting from here the percentage of forms with pelagic larvae gradually increases as we pass into warmer water, reaching its summit on the tropic shelves. 16. In order to survive in high arctic areas a planktotrophic, pelagic larva has to complete its development from hatching to metamorphosis within I–I ½ months (i.e. the period during which phytoplankton production takes place) at a temperature below 2–4 o C. Most larvae, that is in 95% of the species, are unable to do so and have a non‐pelagic development, but if a pelagic larva is able to develop under these severe conditions the planktotrophic pelagic life seems to afford good opportunities even in the Arctic. Thus the 5 % of arctic invertebrates reproducing in this way comprise several of the species which quantitatively are most common within the area. 17. The antarctic shore fauna has poor conditions similar to those of the Arctic. The longest continuous periods of phytoplankton production are 2 and 3 weeks respectively, and pelagic larvae have, in order to survive, to complete their development within this short space of time at a temperature between 1 and 4 o C. Accordingly, non‐pelagic development is the rule, but most arctic species are able to support their non‐pelagic development by means of much smaller eggs than the antarctic species, where brood protection and viviparity is dominant. The antarctic fauna has apparently had a longer time to develop its tendency to abandon a pelagic life. The greater the size of the individual born, the smaller its relative food requirements and the better its chance of competing under poor food conditions. 18. The relatively few data on reproduction in deep sea invertebrates point to a non‐pelagic development. The larvae of such forms, in order to develop through a planktotrophic pelagic stage, would have to rise by the aid of their own locomotory organs through a water column 2000–4000 m. high or more (often with counteracting currents) to the food producing surface layer, and to cover the same distance when descending to metamorphose and settle. 19. The ecological features common to the deep sea, the arctic and the antarctic seas, which enable the same animals to live and to reproduce there, contribute to explain the ‘equatorial submergence’ of many arctic and antarctic coastal forms. 20. In the tropical coastal zones where the percentage of species with pelagic larvae reaches its maximum, the production of food for the larvae takes place much more continuously than in temperate and arctic seas, because light conditions enable the phytoplankton to assimilate all the year round. The tropical species of marine invertebrates breed (in contrast to temperate and arctic species) within such different seasons that their larval stock, taken as a whole, is more or less equally distributed in the plankton all the year round. This makes the competition in the plankton less keen. 21. The fact that a mode of reproduction and development, well fit for an arctic area, is unfit in a temperate or tropical area of the sea is probably one of the main reasons for the restricted distribution of species. 22. In most groups of marine invertebrates the individual species have only one mode of reproduction and development, which accordingly restricts their area of distribution. In the polychaetes, however, the individual species often show an astonishing lability in their mode of reproduction and development which enables them to compete in wide areas of the sea. Thus, out of the Western European species of polychaetes, 28‐4% have been found also in the Indian Ocean, and 18%, at least, along the Californian coast, while the corresponding number of Western European echinoderms, prosobranchs and lamellibranchs found also in the Indian Ocean and California amounts to less than 2%. 23. The pelagic or non‐pelagic development of marine prosobranchs has proved to be a very fine ‘barometer’ for ecological conditions. Recent observations, still not elaborated, seem to indicate that the shape of the top whorls, the apex, of the adult shells of prosobranchs may show whether the species in question has a pelagic or a non‐pelagic development. This discovery may also give us valuable information about the larval development in fossil species, and help us to form an idea about ecological conditions in sea areas from earlier geological periods.

@article{thorson1950reproductive,
    author = "THORSON, GUNNAR",
    title = "REPRODUCTIVE and LARVAL ECOLOGY OF MARINE BOTTOM INVERTEBRATES",
    year = "1950",
    journal = "Biological Reviews",
    abstract = "Summary 1. In analysing the ecological conditions of an animal population we have above all to focus our attention upon the most sensitive stages within the life cycle of the animal, that is, the period of breeding and larval development. 2. Most animal populations on the sea bottom maintain the qualitatively composition of the species composing them, over long periods of time, though the individual species use quite different modes of reproduction and development. This shows that species producing a large number of eggs have a larger wastage of eggs and larvae than those with only a few eggs. The wastage of eggs in the sea is much larger than on the land and in fresh water. 3. In the invertebrate populations on the level sea bottom, large fluctuations in numbers from year to year indicate species with a long pelagic larval life, while a more or less constant occurrence indicates species with a very short pelagic life or a non‐pelagic development. 4. In most marine invertebrates which shed their eggs and sperm freely in the water, either (a) the males are the first to spawn, thus stimulating the females to shed their eggs, or (b) an ‘epidemic spawning’ of a whole population takes place within a few hours. Both methods greatly favour the possibility of fertilization of the eggs spawned and show that the heavy wastage of eggs and larvae takes place after fertilization, during the free swimming pelagic life. 5. Embryos with a non‐pelagic development may originate (a) from large yolky eggs, in which case all the hatching young of the same species will be at the same stage of development, or (b) from small eggs which during their development feed on nurse eggs, when the individual embryos of the same species may vary enormously in size at the stage of hatching. 6. Three types of pelagic larvae are known: (a) Lecithotrophic larvae, originating from large yolky eggs spawned in small numbers by the individual mother animals; they are independent of the plankton as a source of food although growing during pelagic life, are absent from high arctic seas but constitute about 1 o \% of the species with pelagic larvae in all other seas, (b) The planktotrophic larvae with a long pelagic life, originating from small eggs spawned in huge numbers by the individual mother animal; they feed from, and grow in, the plankton, constituting less than 5\% of high arctic bottom invertebrates, 55–65\% of the species in boreal seas, and 8 o ‐85 \% of the tropical species, (c) The planktotrophic larvae with a short pelagic life having the same size and organization at the moment of hatching and at the moment of settling; these constitute about 5\% of the species in all Recent seas. 7. To find out the factors which cause the enormous waste of eggs and larvae, we thus have to study those forms (constituting 7 o \% of all species of bottom invertebrates in Recent seas) which have a long planktotrophic pelagic life, as only species reproducing in this way have really large numbers of eggs. 8. The food requirements of the planktotrophic pelagic larvae are much greater than those of the adult animals at the bottom. The adaptability of the larvae to poor food conditions seems, nevertheless, to be greater than hitherto believed. The significance of starvation seems mainly to be an indirect one: poor food conditions cause slow growth, prolong larval life, and give the enemies a longer interval of time to attack and eat the larvae. 9. At the temperatures to which they are normally exposed, northern as well as tropical larvae seem on an average to spend a similar time (about 3 weeks) in the plankton. The length of the pelagic life of the individual species may, however, vary significantly in nature. In the Sound (Denmark) the larvae are never exposed to temperatures outside the range which they are able to endure. The wastage caused by temperature, like that due to starvation, seems mainly to be an indirect one: low temperatures postpone growth and metamorphosis, and give the enemies a longer time to feed on the larvae. 1 o. When a larva feeding on a pure algal diet metamorphoses into a carnivorous bottom stage, a ‘physiological revolution’ occurs and a huge waste of larvae might be expected. Experiments have, however, shown that this is not the case. 11. Young pelagic larvae are photopositive and crowd near the surface; larvae about to metamorphose are photonegative. Larval polychaetes, echinoderms, and presumably also prosobranchs, may prolong their pelagic life for days or weeks until they find a suitable substratum. Forced towards the bottom by their photonegativity and transported by currents over wide bottom areas, testing the substratum at intervals, their chance of finding a suitable place for settling is much better than hitherto believed. 12. Continuous currents from the continental shelf towards the open ocean may transport larvae from the coast to the deep sea where they will perish. Such conditions may (for instance in the Gulf of Guinea) deeply influence the composition of the fauna, while in other areas (European western coast, southern California) they seem to be only of small significance. 13. The toll levied by enemies appears to be the most essential source of waste among the larvae. A list of such enemies, comprising other pelagic larvae, holoplank‐tonic animals and bottom animals, is given on p. 2 o. A medium‐sized Mytilus edulis, filtering 1–4 1. of water per hour, may retain and kill about 100,000 pelagic lamellibranch larvae in 24 hr. during the maximum breeding season in a Danish fjord. 14. Species reproducing in a vegetative way, by fission, laceration, budding, etc., might be expected to have good chances of competition in such areas where conditions for sexual reproduction are unfavourable. Nevertheless, they only supply a rather small percentage of the animal populations of all Recent seas, probably because their intensity of reproduction is low and because they are unable to spread to new areas. Most forms reproducing in a vegetative way have sexual reproduction as well. 15. Pelagic development is nearly or totally suspended in the deep sea, and is restricted to the shelf faunas. In the arctic and antarctic seas pelagic development is nearly or totally suppressed, even in the shelf faunas, but starting from here the percentage of forms with pelagic larvae gradually increases as we pass into warmer water, reaching its summit on the tropic shelves. 16. In order to survive in high arctic areas a planktotrophic, pelagic larva has to complete its development from hatching to metamorphosis within I–I ½ months (i.e. the period during which phytoplankton production takes place) at a temperature below 2–4 o C. Most larvae, that is in 95\% of the species, are unable to do so and have a non‐pelagic development, but if a pelagic larva is able to develop under these severe conditions the planktotrophic pelagic life seems to afford good opportunities even in the Arctic. Thus the 5 \% of arctic invertebrates reproducing in this way comprise several of the species which quantitatively are most common within the area. 17. The antarctic shore fauna has poor conditions similar to those of the Arctic. The longest continuous periods of phytoplankton production are 2 and 3 weeks respectively, and pelagic larvae have, in order to survive, to complete their development within this short space of time at a temperature between 1 and 4 o C. Accordingly, non‐pelagic development is the rule, but most arctic species are able to support their non‐pelagic development by means of much smaller eggs than the antarctic species, where brood protection and viviparity is dominant. The antarctic fauna has apparently had a longer time to develop its tendency to abandon a pelagic life. The greater the size of the individual born, the smaller its relative food requirements and the better its chance of competing under poor food conditions. 18. The relatively few data on reproduction in deep sea invertebrates point to a non‐pelagic development. The larvae of such forms, in order to develop through a planktotrophic pelagic stage, would have to rise by the aid of their own locomotory organs through a water column 2000–4000 m. high or more (often with counteracting currents) to the food producing surface layer, and to cover the same distance when descending to metamorphose and settle. 19. The ecological features common to the deep sea, the arctic and the antarctic seas, which enable the same animals to live and to reproduce there, contribute to explain the ‘equatorial submergence’ of many arctic and antarctic coastal forms. 20. In the tropical coastal zones where the percentage of species with pelagic larvae reaches its maximum, the production of food for the larvae takes place much more continuously than in temperate and arctic seas, because light conditions enable the phytoplankton to assimilate all the year round. The tropical species of marine invertebrates breed (in contrast to temperate and arctic species) within such different seasons that their larval stock, taken as a whole, is more or less equally distributed in the plankton all the year round. This makes the competition in the plankton less keen. 21. The fact that a mode of reproduction and development, well fit for an arctic area, is unfit in a temperate or tropical area of the sea is probably one of the main reasons for the restricted distribution of species. 22. In most groups of marine invertebrates the individual species have only one mode of reproduction and development, which accordingly restricts their area of distribution. In the polychaetes, however, the individual species often show an astonishing lability in their mode of reproduction and development which enables them to compete in wide areas of the sea. Thus, out of the Western European species of polychaetes, 28‐4\% have been found also in the Indian Ocean, and 18\%, at least, along the Californian coast, while the corresponding number of Western European echinoderms, prosobranchs and lamellibranchs found also in the Indian Ocean and California amounts to less than 2\%. 23. The pelagic or non‐pelagic development of marine prosobranchs has proved to be a very fine ‘barometer’ for ecological conditions. Recent observations, still not elaborated, seem to indicate that the shape of the top whorls, the apex, of the adult shells of prosobranchs may show whether the species in question has a pelagic or a non‐pelagic development. This discovery may also give us valuable information about the larval development in fossil species, and help us to form an idea about ecological conditions in sea areas from earlier geological periods.",
    url = "https://doi.org/10.1111/j.1469-185x.1950.tb00585.x",
    doi = "10.1111/j.1469-185x.1950.tb00585.x",
    number = "1",
    openalex = "W2064001070",
    pages = "1-45",
    volume = "25",
    references = "doi101017s0025315400000102, doi101017s0025315400011917, doi101017s0025315400073690, doi101098rstb19140016, doi101126science1082810489, doi1023071948665, doi1023072420105, doi105962bhltitle11376, doi105962bhltitle6841, openalexw2968710936"
}

Mathematical models are described relating reproductive energetic efficiency to egg size in marine benthic invertebrates with planktonic and nonplanktonic prefeeding larval development. The models are based on simplified assumptions concerning planktonic and benthic predation and the relations between egg size and method of larval nutrition and between egg size and duration of larval life. The model's predictions include: (a) only the extremes of the possible range of egg size and method of nutrition (i.e., planktotrophy, lecithotrophy) are evolutionarily stable; (b) over a certain range of environmental parameters, the two developmental modes are both evolutionarily stable; (c) planktotrophy is more efficient than lecithotrophy when planktonic food is abundant and planktonic predation low, and lecithotrophy more efficient when either or both of these conditions is reversed; and (d) benthic prefeeding development results in greater efficiency when lecithotrophic development time is long and/or planktonic predation more intense than benthic predation, and planktonic prefeeding development is more efficient when these conditions are reversed. Known geographic trends in developmental patterns are discussed in light of these results, and possible explanations for these trends are offered. Ways of testing the predictions and explanations of geographical trends are suggested.

@article{doi101086282838,
    author = "Vance, Richard R.",
    title = "On Reproductive Strategies in Marine Benthic Invertebrates",
    year = "1973",
    journal = "The American Naturalist",
    abstract = "Mathematical models are described relating reproductive energetic efficiency to egg size in marine benthic invertebrates with planktonic and nonplanktonic prefeeding larval development. The models are based on simplified assumptions concerning planktonic and benthic predation and the relations between egg size and method of larval nutrition and between egg size and duration of larval life. The model's predictions include: (a) only the extremes of the possible range of egg size and method of nutrition (i.e., planktotrophy, lecithotrophy) are evolutionarily stable; (b) over a certain range of environmental parameters, the two developmental modes are both evolutionarily stable; (c) planktotrophy is more efficient than lecithotrophy when planktonic food is abundant and planktonic predation low, and lecithotrophy more efficient when either or both of these conditions is reversed; and (d) benthic prefeeding development results in greater efficiency when lecithotrophic development time is long and/or planktonic predation more intense than benthic predation, and planktonic prefeeding development is more efficient when these conditions are reversed. Known geographic trends in developmental patterns are discussed in light of these results, and possible explanations for these trends are offered. Ways of testing the predictions and explanations of geographical trends are suggested.",
    url = "https://doi.org/10.1086/282838",
    doi = "10.1086/282838",
    openalex = "W1966594912"
}

@book{doi101016b9780122825057x50015,
    title = "Reproduction of Marine Invertebrates",
    year = "1979",
    booktitle = "Elsevier eBooks",
    url = "https://doi.org/10.1016/b978-0-12-282505-7.x5001-5",
    doi = "10.1016/b978-0-12-282505-7.x5001-5",
    openalex = "W1562702058"
}

@misc{stanley1979macroevolution2,
    author = "Stanley, S. M",
    title = "Macroevolution",
    year = "1979",
    howpublished = "Pattern and Process: San Francisco, W.H. Freeman",
    note = "talkorigins\_source = {true}; raw\_reference = {Stanley, S. M., 1979, Macroevolution: Pattern and Process: San Francisco, W.H. Freeman.}"
}

@misc{stanley1980macroevolution3,
    author = "Stanley, S. M",
    title = "Macroevolution",
    year = "1980",
    howpublished = "Pattern and Process: San Francisco, Freeman",
    note = "talkorigins\_source = {true}; raw\_reference = {Stanley, S. M., 1980, Macroevolution: Pattern and Process: San Francisco, Freeman.}"
}

Summary 1. Modes of larval development play important roles in the ecology, biogeography, and evolution of marine benthic organisms. Studies of the larval ecology of fossil organisms can contribute greatly to our understanding of such roles by allowing us to race effects on evolutionary time scales. 2. Modes of development can be inferred for well preserved molluscan fossils because the size of the initial larval shell (Protoconch I in gastropods, Prodissoconch I in bivalves) reflects egg size. Other morphological criteria are also available, and a comparative approach based on related taxa with known development may be the most reliable method. By combining larval and adult traits, it is possible to recognize modes of larval development in at least some fossil bryozoans, brachiopods, and echinoderms as well. (a) Planktotrophic larvae arise from small eggs, are released in enormous numbers with little parental investment per offspring, and suffer tremendous mortality during and shortly after a planktic existence. These larvae feed on the plankton during development, and are commonly capable of a prolonged free‐swimming existence, and thus wide dispersal. (b) Nonplanktotrophic larvae (which include both planktic lecithotrophic forms and ‘direct developers’) generally arise from large eggs, with relatively few young produced per parent. Relative to planktotrophic larvae, nonplanktotrophic larvae generally receive greater parental investment per larva, and larval mortality is generally lower. These larvae rely on yolk for nutrition during development, and planktic durations are generally much briefer than for species with planktotrophic larvae, so that dispersal capability is considerably less. Energetic investment per egg is generally higher than in planktotrophs, but as there are lower fecundities as well it is difficult to generalize about the total energetic cost of one mode of reproduction against the other. 3. Owing to the high dispersal capability of planktotrophic larvae, it has been suggested that species with such larvae will be geographically widespread, geologically long‐ranging, and exhibit low speciation and extinction rates. Species with nonplanktotrophic larvae will tend to be geographically more restricted, geologically short‐ranging, and exhibit high speciation and extinction rates (again, as a consequence of their characteristically low larval dispersal capabilities). 4. Recognition of differential dispersal capabilities can play a role in paleobiogeo‐graphic analyses. Concurrent study of the distribution of groups with contrasting modes of development will permit testing of hypotheses concerning timing, magnitudes and frequencies of migration and vicariance events. 5. Larval types are not randomly distributed in the oceans, but relationships with other aspects of the organisms' biology and habitats are very complex. Mode of development varies with: (a) Ecology. A simple r–––K model of adaptive strategies is clearly insufficient to explain the observed relationships: while many ‘equilibrium’ species have nonplanktotrophic larvae, and organisms living in less prdictable environments often have planktotrophic larvae, some of the most opportunistic marine species have nonplanktotrophic larvae. Nonetheless, planktotrophic development seems most suited for exploitation of patchy but widespread habitats. (b) Latitude. At shelf depths, planktotrophy is predominant in the tropics, and decreases sharply at high latitudes. (c) Depth. Incidence of planktotrophy decreases with depth across the continental shelf, at least in some taxa. Beyond the shelf, many deep‐sea organisms are nonplanktotrophic (e.g. most bivalves, peracarid crustaceans), but planktotrophic development appears to be present in other groups (prosobranch gastropods, ophiuroids, and bivalves inhabiting transient habitats such as sunken wood and hydrothermal vents). These trends in developmental types will be accompanied by trends in evolutionary rates and patterns as outlined above. The study of larval ecology by paleobiologists will yield insights into the processes that gave rise to ancient evolutionary and biogeographic patterns, and will permit the development and testing of hypotheses on the origins of the patterns observed in modern seas.

@article{jablonski1983larval,
    author = "JABLONSKI, DAVID and LUTZ, RICHARD A.",
    title = "LARVAL ECOLOGY OF MARINE BENTHIC INVERTEBRATES: PALEOBIOLOGICAL IMPLICATIONS",
    year = "1983",
    journal = "Biological Reviews",
    abstract = "Summary 1. Modes of larval development play important roles in the ecology, biogeography, and evolution of marine benthic organisms. Studies of the larval ecology of fossil organisms can contribute greatly to our understanding of such roles by allowing us to race effects on evolutionary time scales. 2. Modes of development can be inferred for well preserved molluscan fossils because the size of the initial larval shell (Protoconch I in gastropods, Prodissoconch I in bivalves) reflects egg size. Other morphological criteria are also available, and a comparative approach based on related taxa with known development may be the most reliable method. By combining larval and adult traits, it is possible to recognize modes of larval development in at least some fossil bryozoans, brachiopods, and echinoderms as well. (a) Planktotrophic larvae arise from small eggs, are released in enormous numbers with little parental investment per offspring, and suffer tremendous mortality during and shortly after a planktic existence. These larvae feed on the plankton during development, and are commonly capable of a prolonged free‐swimming existence, and thus wide dispersal. (b) Nonplanktotrophic larvae (which include both planktic lecithotrophic forms and ‘direct developers’) generally arise from large eggs, with relatively few young produced per parent. Relative to planktotrophic larvae, nonplanktotrophic larvae generally receive greater parental investment per larva, and larval mortality is generally lower. These larvae rely on yolk for nutrition during development, and planktic durations are generally much briefer than for species with planktotrophic larvae, so that dispersal capability is considerably less. Energetic investment per egg is generally higher than in planktotrophs, but as there are lower fecundities as well it is difficult to generalize about the total energetic cost of one mode of reproduction against the other. 3. Owing to the high dispersal capability of planktotrophic larvae, it has been suggested that species with such larvae will be geographically widespread, geologically long‐ranging, and exhibit low speciation and extinction rates. Species with nonplanktotrophic larvae will tend to be geographically more restricted, geologically short‐ranging, and exhibit high speciation and extinction rates (again, as a consequence of their characteristically low larval dispersal capabilities). 4. Recognition of differential dispersal capabilities can play a role in paleobiogeo‐graphic analyses. Concurrent study of the distribution of groups with contrasting modes of development will permit testing of hypotheses concerning timing, magnitudes and frequencies of migration and vicariance events. 5. Larval types are not randomly distributed in the oceans, but relationships with other aspects of the organisms' biology and habitats are very complex. Mode of development varies with: (a) Ecology. A simple r–––K model of adaptive strategies is clearly insufficient to explain the observed relationships: while many ‘equilibrium’ species have nonplanktotrophic larvae, and organisms living in less prdictable environments often have planktotrophic larvae, some of the most opportunistic marine species have nonplanktotrophic larvae. Nonetheless, planktotrophic development seems most suited for exploitation of patchy but widespread habitats. (b) Latitude. At shelf depths, planktotrophy is predominant in the tropics, and decreases sharply at high latitudes. (c) Depth. Incidence of planktotrophy decreases with depth across the continental shelf, at least in some taxa. Beyond the shelf, many deep‐sea organisms are nonplanktotrophic (e.g. most bivalves, peracarid crustaceans), but planktotrophic development appears to be present in other groups (prosobranch gastropods, ophiuroids, and bivalves inhabiting transient habitats such as sunken wood and hydrothermal vents). These trends in developmental types will be accompanied by trends in evolutionary rates and patterns as outlined above. The study of larval ecology by paleobiologists will yield insights into the processes that gave rise to ancient evolutionary and biogeographic patterns, and will permit the development and testing of hypotheses on the origins of the patterns observed in modern seas.",
    url = "https://doi.org/10.1111/j.1469-185x.1983.tb00380.x",
    doi = "10.1111/j.1469-185x.1983.tb00380.x",
    number = "1",
    openalex = "W2060347297",
    pages = "21-89",
    volume = "58",
    references = "doi101016b9780122825057x50015, doi101017s0094837300005224, doi101017s0094837300005236, doi101086282697, doi101086409052, doi101126science150369228, doi1015159781400881376, doi1023071483846, doi104159harvard9780674865327, openalexw2506868775, openalexw3135630760"
}

Field studies demonstrate that the population structure of the barnacle Balanus glandula differs between locations of high and low larval settlement rate. These observations, together with results from a model for the demography of an open, space-limited population, suggest that the settlement rate may be a more important determinant of rocky intertidal community structure than is presently realized. Locations with a low larval settlement rate exhibit a generally low abundance of barnacles that varies slightly within years and greatly between years, reflecting yearly differences in settlement. Locations with a high-settlement rate exhibit a generally high abudance of barnacles. However, the abundance varies greatly within years with a significant oscillatory component (period, 30 weeks) and only slightly between years regardless of yearly differences in settlement. At the low-settlement location mortality of barnacles is independent of the area occupied by barnacles. At the high-settlement location mortality is cover-dependent due to increased predation by starfish on areas of high barnacle cover. In both locations the cover-independent component of mortality does not vary with age during the first 60 weeks. As assumed in the demographic model, the kinetics of larval settlement can be described as a process in which the rate of settlement to a quadrat is proportional to the fraction of vacant space within the quadrat. Generalizations that the highest species diversity in a rocky intertidal community is found at locations of intermediate disturbance, and that competition causes zonation between species of the barnacle genera Balanus and Chthamalus, seem to apply only to locations with high-settlement rates.

@article{doi101073pnas82113707,
    author = "Gaines, Steven D. and Roughgarden, Joan",
    title = "Larval settlement rate: A leading determinant of structure in an ecological community of the marine intertidal zone",
    year = "1985",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Field studies demonstrate that the population structure of the barnacle Balanus glandula differs between locations of high and low larval settlement rate. These observations, together with results from a model for the demography of an open, space-limited population, suggest that the settlement rate may be a more important determinant of rocky intertidal community structure than is presently realized. Locations with a low larval settlement rate exhibit a generally low abundance of barnacles that varies slightly within years and greatly between years, reflecting yearly differences in settlement. Locations with a high-settlement rate exhibit a generally high abudance of barnacles. However, the abundance varies greatly within years with a significant oscillatory component (period, 30 weeks) and only slightly between years regardless of yearly differences in settlement. At the low-settlement location mortality of barnacles is independent of the area occupied by barnacles. At the high-settlement location mortality is cover-dependent due to increased predation by starfish on areas of high barnacle cover. In both locations the cover-independent component of mortality does not vary with age during the first 60 weeks. As assumed in the demographic model, the kinetics of larval settlement can be described as a process in which the rate of settlement to a quadrat is proportional to the fraction of vacant space within the quadrat. Generalizations that the highest species diversity in a rocky intertidal community is found at locations of intermediate disturbance, and that competition causes zonation between species of the barnacle genera Balanus and Chthamalus, seem to apply only to locations with high-settlement rates.",
    url = "https://doi.org/10.1073/pnas.82.11.3707",
    doi = "10.1073/pnas.82.11.3707",
    openalex = "W2016744291",
    references = "doi1010079783642701573, doi1010160302352475900389, doi101038260204c0, doi101073pnas7172744, doi101111j155856461980tb04043x, doi101126science2194583419, doi1023072407184, doi102475ajs2785766, hartnoll1975chemoreception, openalexw2273005662, openalexw560961838"
}

Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes,...Read More

@article{doi101146annureves16110185002011,
    author = "Strathmann, Richard R.",
    title = "Feeding and Nonfeeding Larval Development and Life-History Evolution in Marine Invertebrates",
    year = "1985",
    journal = "Annual Review of Ecology and Systematics",
    abstract = "Species distribution models (SDMs) are numerical tools that combine observations of species occurrence or abundance with environmental estimates. They are used to gain ecological and evolutionary insights and to predict distributions across landscapes,...Read More",
    url = "https://doi.org/10.1146/annurev.es.16.110185.002011",
    doi = "10.1146/annurev.es.16.110185.002011",
    openalex = "W2177201218",
    references = "connell1961effects, doi101007bf00397496, doi101086282553, doi101086282838, doi101111j1469185x1983tb00380x, doi101111j155856461978tb04642x, doi101126science2224620159, doi101139f77008, doi1023071938326, doi1023071942441, jablonski1983larval, openalexw3213326676"
}

We introduce a demographic model for a local population of sessile marine invertebrates that have a pelagic larval phase. The processes in the model are the settling of larvae onto empty space, and the growth and mortality of the settled organisms. The rate of settlement per unit of unoccupied space is assumed to be determined by factors outside of the local system. The model predicts the number of animals of each age in the local system through time. The model is offered in both discrete and continuous—time versions. The principal result is that the growth of the settled organisms is destabilizing. In the model, there is always a state where recruitment balances mortality. However, growth can interfere with recruitment and can destabilize this steady state, provided also that the settlement rate is sufficiently high. The model suggests that two qualitatively distinct pictures of population structure result, depending on the settlement rate. In the high settlement limit, the intertidal landscape is a mosaic of cohorts, punctuated with occasional gaps of vacant substrate. In the low settlement limit, the intertidal landscape has vacant space and organisms of all ages mixed together and spatial variation in abundance is caused by microgeographic variation in settlement and mortality rates.

@article{doi1023071941306,
    author = "Roughgarden, Jonathan and Iwasa, Yoh and Baxter, Charles",
    title = "Demographic Theory for an Open Marine Population with Space‐Limited Recruitment",
    year = "1985",
    journal = "Ecology",
    abstract = "We introduce a demographic model for a local population of sessile marine invertebrates that have a pelagic larval phase. The processes in the model are the settling of larvae onto empty space, and the growth and mortality of the settled organisms. The rate of settlement per unit of unoccupied space is assumed to be determined by factors outside of the local system. The model predicts the number of animals of each age in the local system through time. The model is offered in both discrete and continuous—time versions. The principal result is that the growth of the settled organisms is destabilizing. In the model, there is always a state where recruitment balances mortality. However, growth can interfere with recruitment and can destabilize this steady state, provided also that the settlement rate is sufficiently high. The model suggests that two qualitatively distinct pictures of population structure result, depending on the settlement rate. In the high settlement limit, the intertidal landscape is a mosaic of cohorts, punctuated with occasional gaps of vacant substrate. In the low settlement limit, the intertidal landscape has vacant space and organisms of all ages mixed together and spatial variation in abundance is caused by microgeographic variation in settlement and mortality rates.",
    url = "https://doi.org/10.2307/1941306",
    doi = "10.2307/1941306",
    openalex = "W1976714871"
}

@techreport{jablonski1986larval1,
    author = "Jablonski, D",
    title = "Larval ecology and macroevolution in marine invertebrates",
    year = "1986",
    howpublished = "Bulletin of Marine Science, v. 39, p. 565-587",
    note = "talkorigins\_source = {true}; raw\_reference = {Jablonski, D., 1986, Larval ecology and macroevolution in marine invertebrates: Bulletin of Marine Science, v. 39, p. 565-587.}"
}

@article{doi1010160169534789900086,
    author = "Underwood, A.J. and Fairweather, Peter G.",
    title = "Supply-side ecology and benthic marine assemblages",
    year = "1989",
    journal = "Trends in Ecology \& Evolution",
    url = "https://doi.org/10.1016/0169-5347(89)90008-6",
    doi = "10.1016/0169-5347(89)90008-6",
    openalex = "W2073729508",
    references = "doi10100797814899732526, doi101086282400, doi101086284105, doi101086284741, doi101111j1469185x1950tb00585x, doi101126science19943351302, doi101139f54039, doi1023071948498, doi1023072529762, openalexw1986779979, thorson1950reproductive"
}

Differences in the larval ecology of Ordovician trilobites directly influenced the outcome of the Ashgill extinction (latest Ordovician) and indirectly governed the pattern of evolution in post-Ordovician trilobites. Larval ecology also affected survivorship patterns within the Ordovician, particularly between the Llandeilo and the Caradoc stages. All taxa with pelagic adults became extinct by the end of the Ordovician. Similarly, trilobites with entirely planktonic larvae had all but disappeared by the end of the Ordovician. Although suffering a significant loss in diversity, taxa with benthic larvae provided the ancestral stock for the majority of post-Ordovician lineages. Trilobites with a two-stage protaspid period (single planktonic followed by benthic larvae) suffered least during the Ashgill extinction, giving rise to approximately 23% of the new genera appearing in the early Silurian. Patterns of extinction/survivorship among trilobite taxa with different developmental strategies indicate that the so-called Ashgill extinction was most likely the result of a composite phenomenon, including environmental perturbations, ecosystem breakdown and biogeographic restriction, and was not the consequence of a single catastrophic event (e.g., bolide collision). Indeed, our results are consistent with extinction models which invoke periodic global cooling and sea level regression associated with glaciation. Taxa with planktonic larvae first suffered a marked decline in diversity between the Llandeilo and the Caradoc (end of Middle Ordovician), coincident with the onset of the Ordovician-Silurian glaciation. During this time interval, the paleogeographic ranges of most surviving genera with solely planktonic larvae were severely constricted to lower latitude paleobiogeographic provinces. During the Ashgill (Rawtheyan to Hirnantian), climatic and sea level fluctuations were most extreme because of continued and more extensive glaciation. At this time, when extinctions were particularly severe, there was also a significant effect upon the survivorship of taxa with benthic larvae. Our results indicate that the proportion of the life cycle spent in the water column, dependent upon a planktonic food source, was a critical factor in the survivorship of trilobite taxa during Middle to Late Ordovician time. Consequently, differences in life history patterns predisposed individual taxa to survival or extinction.

@article{doi101017s0094837300009313,
    author = "Chatterton, Brian D. E. and Speyer, Stephen E.",
    title = "Larval ecology, life history strategies, and patterns of extinction and survivorship among Ordovician trilobites",
    year = "1989",
    journal = "Paleobiology",
    abstract = "Differences in the larval ecology of Ordovician trilobites directly influenced the outcome of the Ashgill extinction (latest Ordovician) and indirectly governed the pattern of evolution in post-Ordovician trilobites. Larval ecology also affected survivorship patterns within the Ordovician, particularly between the Llandeilo and the Caradoc stages. All taxa with pelagic adults became extinct by the end of the Ordovician. Similarly, trilobites with entirely planktonic larvae had all but disappeared by the end of the Ordovician. Although suffering a significant loss in diversity, taxa with benthic larvae provided the ancestral stock for the majority of post-Ordovician lineages. Trilobites with a two-stage protaspid period (single planktonic followed by benthic larvae) suffered least during the Ashgill extinction, giving rise to approximately 23\% of the new genera appearing in the early Silurian. Patterns of extinction/survivorship among trilobite taxa with different developmental strategies indicate that the so-called Ashgill extinction was most likely the result of a composite phenomenon, including environmental perturbations, ecosystem breakdown and biogeographic restriction, and was not the consequence of a single catastrophic event (e.g., bolide collision). Indeed, our results are consistent with extinction models which invoke periodic global cooling and sea level regression associated with glaciation. Taxa with planktonic larvae first suffered a marked decline in diversity between the Llandeilo and the Caradoc (end of Middle Ordovician), coincident with the onset of the Ordovician-Silurian glaciation. During this time interval, the paleogeographic ranges of most surviving genera with solely planktonic larvae were severely constricted to lower latitude paleobiogeographic provinces. During the Ashgill (Rawtheyan to Hirnantian), climatic and sea level fluctuations were most extreme because of continued and more extensive glaciation. At this time, when extinctions were particularly severe, there was also a significant effect upon the survivorship of taxa with benthic larvae. Our results indicate that the proportion of the life cycle spent in the water column, dependent upon a planktonic food source, was a critical factor in the survivorship of trilobite taxa during Middle to Late Ordovician time. Consequently, differences in life history patterns predisposed individual taxa to survival or extinction.",
    url = "https://doi.org/10.1017/s0094837300009313",
    doi = "10.1017/s0094837300009313",
    openalex = "W2417892224"
}

Silicified trilobite faunas yield a well preserved and abundant record of early development in many taxa. Although their morphologies are well known, protaspid larvae are poorly understood in terms of trilobite life history and developmental biology. Two distinct morphologic types are recognized among the great diversity of protaspides studied; these are termed adult‐like and nonadult‐tike according to gross similarity to later developmental stages. Transitions between nonadult‐like and adult‐like morphologies are abrupt, occurring between successsive instars, and, thereby, constitute metamorphoses. By analogy with developmental patterns among modern marine arthropod taxa, metamorphoses during early trilobite ontogeny correspond to radical modifications in life mode and ecology. Adult‐like trilobite protaspides possess a dorso‐ventrally flattened tergum which displays a coarsely featured prosopon and surface‐parallel spines; these are interpreted as benthic larvae. In contrast, nonadult‐like protaspid larvae display an ovoid to spheroidal shape with spine pairs that project at right angles to one another; these are considered to have been planktonic. Protaspid morphologies are compared and discussed in light of these inferred modes of life.

@article{doi10108008912968909386512,
    author = "Speyer, Stephen E. and Chatterton, Brian D. E.",
    title = "Trilobite larvae and larval ecology",
    year = "1989",
    journal = "Historical Biology",
    abstract = "Silicified trilobite faunas yield a well preserved and abundant record of early development in many taxa. Although their morphologies are well known, protaspid larvae are poorly understood in terms of trilobite life history and developmental biology. Two distinct morphologic types are recognized among the great diversity of protaspides studied; these are termed adult‐like and nonadult‐tike according to gross similarity to later developmental stages. Transitions between nonadult‐like and adult‐like morphologies are abrupt, occurring between successsive instars, and, thereby, constitute metamorphoses. By analogy with developmental patterns among modern marine arthropod taxa, metamorphoses during early trilobite ontogeny correspond to radical modifications in life mode and ecology. Adult‐like trilobite protaspides possess a dorso‐ventrally flattened tergum which displays a coarsely featured prosopon and surface‐parallel spines; these are interpreted as benthic larvae. In contrast, nonadult‐like protaspid larvae display an ovoid to spheroidal shape with spine pairs that project at right angles to one another; these are considered to have been planktonic. Protaspid morphologies are compared and discussed in light of these inferred modes of life.",
    url = "https://doi.org/10.1080/08912968909386512",
    doi = "10.1080/08912968909386512",
    openalex = "W2054274715",
    references = "doi101111j1469185x1986tb00464x"
}

Since Barrande (1852) first illustrated a trilobite larva, aspects of trilobite ontogeny and early development have received a great deal of attention (see Beecher, 1895; Størmer, 1942; Whittington, 1957; Hu, 1971; Chatterton, 1980). Much of this literature, however, is purely descriptive and very little has been done to incorporate these works into a biological synthesis. During the past several decades a great deal has been learned about the role of larval ecology in monitoring biogeographic distributions, cohort survivorship and taxonomic longevity among modern marine invertebrates. This growing body of knowledge has provided the basis for many new insights regarding patterns of extinction and survivorship and macroevolution evident within the fossil record (see Jablonski, 1986; Jablonski and Lutz, 1983).

@article{doi101017s247526300000177x,
    author = "Speyer, Stephen E. and Chatterton, Brian D. E.",
    title = "Trilobite Larvae, Larval Ecology and Developmental Paleobiology",
    year = "1990",
    journal = "Short Courses in Paleontology",
    abstract = "Since Barrande (1852) first illustrated a trilobite larva, aspects of trilobite ontogeny and early development have received a great deal of attention (see Beecher, 1895; Størmer, 1942; Whittington, 1957; Hu, 1971; Chatterton, 1980). Much of this literature, however, is purely descriptive and very little has been done to incorporate these works into a biological synthesis. During the past several decades a great deal has been learned about the role of larval ecology in monitoring biogeographic distributions, cohort survivorship and taxonomic longevity among modern marine invertebrates. This growing body of knowledge has provided the basis for many new insights regarding patterns of extinction and survivorship and macroevolution evident within the fossil record (see Jablonski, 1986; Jablonski and Lutz, 1983).",
    url = "https://doi.org/10.1017/s247526300000177x",
    doi = "10.1017/s247526300000177x",
    openalex = "W3195539169",
    references = "doi101017s0094837300004310, doi101146annureves16110185002011, doi1015159780691224244, doi1015159781400881376, doi1023072412825, doi104159harvard9780674865327, openalexw1528487914, openalexw2506868775, thorson1950reproductive"
}

Abstract Planktonic marine invertebrate embryos and larvae lead transitory lives of great risk and grave uncertainty. Estimation of the magnitude of risk and mortality, however presents a formidable challenge. Three methods are currently in use to estimate levels of mortality among populations of marine invertebrate larvae: 1) theoretical models where rates of instantaneous mortality are correlated with other life history parameters, 2) estimation of mortality based on laboratory observations of predator-prey interactions and 3) analysis of relationships among gamete production, larval populations, and densities of post-larvae in the field. Theoretical exercises indicate that rates of larval mortality are correlated with duration of the planktonic period, and that differences in mortality rates may be offset by differences in egg size and fecundity. Results from laboratory investigations suggest that mortality rates change with larval size or age. Attempts to monitor cohorts of larvae in the plankton offer the most direct evidence for natural mortality, although they often lack confidence that larvae were sampled from a continuous population. Because factors that contribute to the mortality of marine invertebrate embryos and larvae operate concurrently and mortality is a density-dependent and age-specific demographic process, detailed investigations of several synergistic ecological parameters are required to provide meaningful estimates of instantaneous mortality rates in larval populations.

@article{doi10108000785236199010422030,
    author = "Rumrill, Steven S.",
    title = "Natural mortality of marine invertebrate larvae",
    year = "1990",
    journal = "Ophelia",
    abstract = "Abstract Planktonic marine invertebrate embryos and larvae lead transitory lives of great risk and grave uncertainty. Estimation of the magnitude of risk and mortality, however presents a formidable challenge. Three methods are currently in use to estimate levels of mortality among populations of marine invertebrate larvae: 1) theoretical models where rates of instantaneous mortality are correlated with other life history parameters, 2) estimation of mortality based on laboratory observations of predator-prey interactions and 3) analysis of relationships among gamete production, larval populations, and densities of post-larvae in the field. Theoretical exercises indicate that rates of larval mortality are correlated with duration of the planktonic period, and that differences in mortality rates may be offset by differences in egg size and fecundity. Results from laboratory investigations suggest that mortality rates change with larval size or age. Attempts to monitor cohorts of larvae in the plankton offer the most direct evidence for natural mortality, although they often lack confidence that larvae were sampled from a continuous population. Because factors that contribute to the mortality of marine invertebrate embryos and larvae operate concurrently and mortality is a density-dependent and age-specific demographic process, detailed investigations of several synergistic ecological parameters are required to provide meaningful estimates of instantaneous mortality rates in larval populations.",
    url = "https://doi.org/10.1080/00785236.1990.10422030",
    doi = "10.1080/00785236.1990.10422030",
    openalex = "W1969635526",
    references = "doi1010160022098185901467, doi1010160302352475900389, doi101016b9780122825019500065, doi101016b9780122825057x50015, doi101086409052, doi101111j1469185x1950tb00585x, doi101111j1469185x1983tb00380x, doi101111j155856461980tb04043x, doi101126science11538249, doi101126science24749461071, doi101139f77008, doi101146annureves08110177001045, doi101146annureves16110185002011, doi1015159781400852888, hartnoll1975chemoreception, jablonski1983larval, openalexw2888494477, openalexw656118525"
}

@article{young1990larval,
    author = "Young, Craig M.",
    title = "Larval ecology of marine invertebrates: A sesquicentennial history",
    year = "1990",
    journal = "Ophelia",
    url = "https://doi.org/10.1080/00785236.1990.10422023",
    doi = "10.1080/00785236.1990.10422023",
    number = "1-2",
    openalex = "W2071276853",
    pages = "1-48",
    volume = "32",
    references = "doi1010160022098185901467, doi1010160169534789900086, doi101016s0065288108602576, doi101073pnas82113707, doi101126science11538249, doi101146annureves03110172001125, doi1023071933500, doi1023072412825, openalexw1532540194, thorson1950reproductive"
}

It is argued that the problem of pattern and scale is the central problem in ecology, unifying population biology and ecosystems science, and marrying basic and applied ecology. Applied challenges, such as the prediction of the ecological causes and consequences of global climate change, require the interfacing of phenomena that occur on very different scales of space, time, and ecological organization. Furthermore, there is no single natural scale at which ecological phenomena should be studied; systems generally show characteristic variability on a range of spatial, temporal, and organizational scales. The observer imposes a perceptual bias, a filter through which the system is viewed. This has fundamental evolutionary significance, since every organism is an "observer" of the environment, and life history adaptations such as dispersal and dormancy alter the perceptual scales of the species, and the observed variability. It likewise has fundamental significance for our own study of ecological systems, since the patterns that are unique to any range of scales will have unique causes and biological consequences. The key to prediction and understanding lies in the elucidation of mechanisms underlying observed patterns. Typically, these mechanisms operate at different scales than those on which the patterns are observed; in some cases, the patterns must be understood as emerging form the collective behaviors of large ensembles of smaller scale units. In other cases, the pattern is imposed by larger scale constraints. Examination of such phenomena requires the study of how pattern and variability change with the scale of description, and the development of laws for simplification, aggregation, and scaling. Examples are given from the marine and terrestrial literatures.

@article{doi1023071941447,
    author = "Levin, Simon A.",
    title = "The Problem of Pattern and Scale in Ecology: The Robert H. MacArthur Award Lecture",
    year = "1992",
    journal = "Ecology",
    abstract = {It is argued that the problem of pattern and scale is the central problem in ecology, unifying population biology and ecosystems science, and marrying basic and applied ecology. Applied challenges, such as the prediction of the ecological causes and consequences of global climate change, require the interfacing of phenomena that occur on very different scales of space, time, and ecological organization. Furthermore, there is no single natural scale at which ecological phenomena should be studied; systems generally show characteristic variability on a range of spatial, temporal, and organizational scales. The observer imposes a perceptual bias, a filter through which the system is viewed. This has fundamental evolutionary significance, since every organism is an "observer" of the environment, and life history adaptations such as dispersal and dormancy alter the perceptual scales of the species, and the observed variability. It likewise has fundamental significance for our own study of ecological systems, since the patterns that are unique to any range of scales will have unique causes and biological consequences. The key to prediction and understanding lies in the elucidation of mechanisms underlying observed patterns. Typically, these mechanisms operate at different scales than those on which the patterns are observed; in some cases, the patterns must be understood as emerging form the collective behaviors of large ensembles of smaller scale units. In other cases, the pattern is imposed by larger scale constraints. Examination of such phenomena requires the study of how pattern and variability change with the scale of description, and the development of laws for simplification, aggregation, and scaling. Examples are given from the marine and terrestrial literatures.},
    url = "https://doi.org/10.2307/1941447",
    doi = "10.2307/1941447",
    openalex = "W2322480672",
    references = "doi101007bfb0091924, doi101086282400, doi101098rstb19520012, doi101111j146918091937tb02153x, doi101111j155856461964tb01674x, doi1015159781400881376, doi1023071941447, doi1023072529912, doi105860choice295104, doi107551mitpress30140010001, openalexw1558456135, openalexw1576847343"
}

@article{doi1010160077757994900361,
    author = "Leggett, William C. and DeBlois, EM",
    title = "Recruitment in marine fishes: Is it regulated by starvation and predation in the egg and larval stages?",
    year = "1994",
    journal = "Netherlands Journal of Sea Research",
    url = "https://doi.org/10.1016/0077-7579(94)90036-1",
    doi = "10.1016/0077-7579(94)90036-1",
    openalex = "W2009934233",
    references = "doi101016s006528810860187x, doi101139f89086"
}

In marine species, high dispersal is often associated with only mild genetic differentiation over large spatial scales. Despite this generalization, there are numerous reasons for the accumulation of genetic differences between large, semi-isolated marine populations. A suite of well-known evolutionary mechanisms can operate within and between populations to result in genetic divergence, and these mechanisms may well be augmented by newly discovered genetic processes. This variety of mechanisms for genetic divergence is paralleled by great diversity in the types of reproductive isolation shown by recently diverged marine species. Differences in spawning time, mate recognition, environmental tolerance, and gamete compatibility have all been implicated in marine speeiation events. There is substantial evidence for rapid evolution of reproductive isolation in strictly allopatrie populations (e,g. across the Isthmus of Panama). Evidence for the action of selection in increasing reproductive isolation in sympatric populations is fragmentary. Although a great deal of information is available on population genetics, reproductive isolation, and cryptic or sibling species in marine environments, the influence of particular genetic changes on reproductive isolation is poorly understood for marine (or terrestrial) taxa. For a few systems, like the co-evolution of gamete recognition proteins, changes in a small number of genes may give rise to reproductive isolation. Such studies show how a focus on the physiology, ecology, or sensory biology of reproductive isolation can help uncover the

@article{doi101146annureves25110194002555,
    author = "Palumbi, Stephen R.",
    title = "GENETIC DIVERGENCE, REPRODUCTIVE ISOLATION, AND MARINE SPECIATION",
    year = "1994",
    journal = "Annual Review of Ecology and Systematics",
    abstract = "In marine species, high dispersal is often associated with only mild genetic differentiation over large spatial scales. Despite this generalization, there are numerous reasons for the accumulation of genetic differences between large, semi-isolated marine populations. A suite of well-known evolutionary mechanisms can operate within and between populations to result in genetic divergence, and these mechanisms may well be augmented by newly discovered genetic processes. This variety of mechanisms for genetic divergence is paralleled by great diversity in the types of reproductive isolation shown by recently diverged marine species. Differences in spawning time, mate recognition, environmental tolerance, and gamete compatibility have all been implicated in marine speeiation events. There is substantial evidence for rapid evolution of reproductive isolation in strictly allopatrie populations (e,g. across the Isthmus of Panama). Evidence for the action of selection in increasing reproductive isolation in sympatric populations is fragmentary. Although a great deal of information is available on population genetics, reproductive isolation, and cryptic or sibling species in marine environments, the influence of particular genetic changes on reproductive isolation is poorly understood for marine (or terrestrial) taxa. For a few systems, like the co-evolution of gamete recognition proteins, changes in a small number of genes may give rise to reproductive isolation. Such studies show how a focus on the physiology, ecology, or sensory biology of reproductive isolation can help uncover the",
    url = "https://doi.org/10.1146/annurev.es.25.110194.002555",
    doi = "10.1146/annurev.es.25.110194.002555",
    openalex = "W2173143655",
    references = "doi101038365636a0, doi1015159780295743240, doi101722611310, doi1023072412725, openalexw1528487914"
}

@article{eckman1996closing,
    author = "Eckman, James E.",
    title = "Closing the larval loop: linking larval ecology to the population dynamics of marine benthic invertebrates",
    year = "1996",
    journal = "Journal of Experimental Marine Biology and Ecology",
    url = "https://doi.org/10.1016/s0022-0981(96)02644-5",
    doi = "10.1016/s0022-0981(96)02644-5",
    number = "1-2",
    openalex = "W1989491372",
    pages = "207-237",
    volume = "200",
    references = "doi101016b9780122825057x50015, doi101126science11538249, doi1023071939225, doi1023072004855, doi1023072007849, doi1023074220, doi105860choice374524, openalexw1497099219, openalexw171744082, thorson1950reproductive"
}

many benthic marine invertebrates develop by means of free-livlng, dispersive larval stages. The presumed advantages of such larvae include the avoidance of competition for resources with adults, temporary reduct~on of benthic mortality while in the plankton, decreased likelihood of inbreeding in the next generation, and increased ability to withstand local extinction However, the direct~on of evolutionary change appears generally b ~a s e d toward the loss of larvae in many clades, implying that larvae are somehow disadvantageous. Poss~ble disadvantages include dispersal away from favorable habitat, mismatches between larval and luvenile physiological tolerances, greater sus-ceptib~lity to env~ronmental stresses, greater susceptibihty to predation. and vanous costs that may be associated with n~etanlorphosing in response to specific chemical cues and postponing n~etamorphosis in the absence of those cues. Understanding the forces responsible for the present distribution of larval and non-larval (aplanktonlc) development among benthic marine invertebrates, and the potential influence of human activities on the direct~on of future evolutionary change in 1-eproductlve patterns, will require a better understanding of the following issues. the role of macro-evolutionary forces in selecting for or against dispersive larvae, the relative tolerances of encapsulated embryos and free-living larvae to salinity, pollutant, and other environmental stresses; the degree to which egg masses, e g g capsules, and brood chambers protect developing embryos from environmental stresses; the relative magmtude of predation by planktonic and benthic predators on both larvae and early juveniles; the way In which larval and juvenile size affect vulnerability to predators; the extent to w h ~c h encapsulation and brooding protect against predators; the amount of genetic change associated with loss of larvae from invertebrate life cycles and the time required to accomplish that change; and the degree to which continued input of larvae from other populations deters selection against dispersive larvae The prominence of larval development in modern life cycles may reflect difficulties In loslng larvae from llfe cycles more than selection for their retention.

@article{doi103354meps177269,
    author = "Pechenik, JA",
    title = "On the advantages and disadvantages of larval stages in benthic marine invertebrate life cycles",
    year = "1999",
    journal = "Marine Ecology Progress Series",
    abstract = "many benthic marine invertebrates develop by means of free-livlng, dispersive larval stages. The presumed advantages of such larvae include the avoidance of competition for resources with adults, temporary reduct\textasciitilde on of benthic mortality while in the plankton, decreased likelihood of inbreeding in the next generation, and increased ability to withstand local extinction However, the direct\textasciitilde on of evolutionary change appears generally b \textasciitilde a s e d toward the loss of larvae in many clades, implying that larvae are somehow disadvantageous. Poss\textasciitilde ble disadvantages include dispersal away from favorable habitat, mismatches between larval and luvenile physiological tolerances, greater sus-ceptib\textasciitilde lity to env\textasciitilde ronmental stresses, greater susceptibihty to predation. and vanous costs that may be associated with n\textasciitilde etanlorphosing in response to specific chemical cues and postponing n\textasciitilde etamorphosis in the absence of those cues. Understanding the forces responsible for the present distribution of larval and non-larval (aplanktonlc) development among benthic marine invertebrates, and the potential influence of human activities on the direct\textasciitilde on of future evolutionary change in 1-eproductlve patterns, will require a better understanding of the following issues. the role of macro-evolutionary forces in selecting for or against dispersive larvae, the relative tolerances of encapsulated embryos and free-living larvae to salinity, pollutant, and other environmental stresses; the degree to which egg masses, e g g capsules, and brood chambers protect developing embryos from environmental stresses; the relative magmtude of predation by planktonic and benthic predators on both larvae and early juveniles; the way In which larval and juvenile size affect vulnerability to predators; the extent to w h \textasciitilde c h encapsulation and brooding protect against predators; the amount of genetic change associated with loss of larvae from invertebrate life cycles and the time required to accomplish that change; and the degree to which continued input of larvae from other populations deters selection against dispersive larvae The prominence of larval development in modern life cycles may reflect difficulties In loslng larvae from llfe cycles more than selection for their retention.",
    url = "https://doi.org/10.3354/meps177269",
    doi = "10.3354/meps177269",
    openalex = "W2065268282",
    references = "doi1010160169534796100288, doi101016b9780122825057x50015, doi101016s006528810860187x, doi10103841710, doi101126science11538249, doi101146annurevecolsys271237, doi101146annurevecolsys271477, doi101146annureves16110185002011, doi101146annureves16110185002141, doi105860choice341536, thorson1950reproductive"
}

Most marine populations are thought to be well connected via long-distance dispersal of larval stages. Eulerian and Lagrangian flow models, coupled with linear mortality estimates, were used to examine this assumption. The findings show that when simple advection models are used, larval exchange rates may be overestimated; such simplistic models fail to account for a decrease of up to nine orders of magnitude in larval concentrations resulting from diffusion and mortality. The alternative process of larval retention near local populations is shown to exist and may be of great importance in the maintenance of marine population structure and management of coastal marine resources.

@article{doi101126science2875454857,
    author = "Cowen, Robert K. and Lwiza, Kamazima M. M. and Sponaugle, Su and Paris, Claire B. and Olson, Donald B.",
    title = "Connectivity of Marine Populations: Open or Closed?",
    year = "2000",
    journal = "Science",
    abstract = "Most marine populations are thought to be well connected via long-distance dispersal of larval stages. Eulerian and Lagrangian flow models, coupled with linear mortality estimates, were used to examine this assumption. The findings show that when simple advection models are used, larval exchange rates may be overestimated; such simplistic models fail to account for a decrease of up to nine orders of magnitude in larval concentrations resulting from diffusion and mortality. The alternative process of larval retention near local populations is shown to exist and may be of great importance in the maintenance of marine population structure and management of coastal marine resources.",
    url = "https://doi.org/10.1126/science.287.5454.857",
    doi = "10.1126/science.287.5454.857",
    openalex = "W2028232676",
    references = "doi101111j155856461995tb02325x"
}

“Supply-side” ecology recognizes the potential role that recruitment plays in the local population dynamics of open systems. Apart from the applied fisheries literature, the converse link between adults and the production of cohorts of recruits has received much less attention. We used a hierarchical sampling design to investigate the relationships between adult abundance, fecundity, and rates of larval recruitment by acroporid corals on 33 reefs in five sectors (250–400 km apart) stretching from north to south along the length of the Great Barrier Reef, Australia. Our goal was to quantify patterns of recruitment at multiple scales, and to explore the underlying mechanisms. Specifically, we predicted that large-scale patterns of recruitment could be driven by changes in the abundance of adults and/or their fecundity, i.e., that corals exhibit a stock–recruitment relationship. The amount of recruitment by acroporids in each of two breeding seasons varied by more than 35-fold among the five sectors. Adult density varied only twofold among sectors and was not correlated with recruitment at the sector or reef scale. In contrast, fecundity levels (the proportion of colonies on each reef that contained ripe eggs) varied from 15% to 100%, depending on sector, year, and species. Spatial and temporal variation in the fecundity of each of three common Acropora species explained most of the variation (72%) in recruitment by acroporids, indicating that the production of larvae is a major determinant of levels of recruitment at large scales. Once fecundity was accounted for, none of the other variables we examined (sector, reef area, abundance of adults, or year) contributed significantly to variation in recruitment. The relationship between fecundity and recruitment was nonlinear, i.e., rates of recruitment increased disproportionately when and where the proportion of gravid colonies approached 100%. This pattern is consistent with the hypothesis that enhanced fertilization success and/or predator satiation occurs during mass-spawning events. Furthermore, it implies that small, sublethal changes in fecundity of corals could result in major reductions in recruitment.

@article{doi1018900012965820000812241ssewbw20co2,
    author = "Hughes, Terry P. and Baird, Andrew H. and Dinsdale, Elizabeth A. and Moltschaniwskyj, Natalie A. and Pratchett, Morgan S. and Tanner, Jason E. and Willis, Bette L.",
    title = "SUPPLY-SIDE ECOLOGY WORKS BOTH WAYS: THE LINK BETWEEN BENTHIC ADULTS, FECUNDITY, AND LARVAL RECRUITS",
    year = "2000",
    journal = "Ecology",
    abstract = "“Supply-side” ecology recognizes the potential role that recruitment plays in the local population dynamics of open systems. Apart from the applied fisheries literature, the converse link between adults and the production of cohorts of recruits has received much less attention. We used a hierarchical sampling design to investigate the relationships between adult abundance, fecundity, and rates of larval recruitment by acroporid corals on 33 reefs in five sectors (250–400 km apart) stretching from north to south along the length of the Great Barrier Reef, Australia. Our goal was to quantify patterns of recruitment at multiple scales, and to explore the underlying mechanisms. Specifically, we predicted that large-scale patterns of recruitment could be driven by changes in the abundance of adults and/or their fecundity, i.e., that corals exhibit a stock–recruitment relationship. The amount of recruitment by acroporids in each of two breeding seasons varied by more than 35-fold among the five sectors. Adult density varied only twofold among sectors and was not correlated with recruitment at the sector or reef scale. In contrast, fecundity levels (the proportion of colonies on each reef that contained ripe eggs) varied from 15\% to 100\%, depending on sector, year, and species. Spatial and temporal variation in the fecundity of each of three common Acropora species explained most of the variation (72\%) in recruitment by acroporids, indicating that the production of larvae is a major determinant of levels of recruitment at large scales. Once fecundity was accounted for, none of the other variables we examined (sector, reef area, abundance of adults, or year) contributed significantly to variation in recruitment. The relationship between fecundity and recruitment was nonlinear, i.e., rates of recruitment increased disproportionately when and where the proportion of gravid colonies approached 100\%. This pattern is consistent with the hypothesis that enhanced fertilization success and/or predator satiation occurs during mass-spawning events. Furthermore, it implies that small, sublethal changes in fecundity of corals could result in major reductions in recruitment.",
    url = "https://doi.org/10.1890/0012-9658(2000)081[2241:ssewbw]2.0.co;2",
    doi = "10.1890/0012-9658(2000)081[2241:ssewbw]2.0.co;2",
    openalex = "W2000565053",
    references = "eckman1996closing"
}

Studies in terrestrial systems suggest that long-distance propagule dispersal is important for landscape pattern and dynamics, but largely inconsequential for local demography. By contrast, in marine systems, dispersal at regional scales may drive local dynamics, because many species may have large mean dispersal distances. To assess variation in marine dispersal scales, we estimated mean dispersal distances from genetic isolation-by-distance slopes. Estimates ranged widely, from a few meters to hundreds of kilometers. Dispersal differed among taxonomic groups (macroalgae, invertebrates, and fish) and among species in different functional groups (e.g., producers and herbivores). Differences in dispersal scale have important implications for marine community dynamics, reserve design, responses to large-scale perturbations, and evolution of interacting species. To place genetic estimates of marine dispersal in context, we compared them to other measures of dispersal in the ocean and to estimates of dispersal on land. Maximum scales of dispersal by sedentary marine species exceeded maximum estimates of terrestrial plant dispersal by at least one to two orders of magnitude. Direct and genetic estimates of terrestrial plant dispersal were comparable to estimates of marine plant dispersal. Rates of marine macroalgal range expansion, however, far exceeded spread rates of terrestrial plants. Terrestrial plant spread rates were more similar to those of short-dispersing marine organisms that lack secondary dispersal by drifting adults. Genetic estimates of dispersal by different functional groups suggest that herbivores typically disperse much farther than their plant resources both on land and in the sea, although the timing, frequency, and consequences of dispersal may differ in the two systems. Terrestrial herbivores have more flexible dispersal behavior than marine organisms that disperse each generation by planktonic transport of larvae. Our results validate some long-standing views about the greater dispersal potential of species in the ocean, but also highlight the extreme heterogeneity in dispersal scale among marine species. As a result, development of a community perspective on marine connectivity will require consideration of multiple dispersal mechanisms and scales.

@article{doi101890010622,
    author = "Kinlan, Brian P. and Gaines, Steven D.",
    title = "PROPAGULE DISPERSAL IN MARINE AND TERRESTRIAL ENVIRONMENTS: A COMMUNITY PERSPECTIVE",
    year = "2003",
    journal = "Ecology",
    abstract = "Studies in terrestrial systems suggest that long-distance propagule dispersal is important for landscape pattern and dynamics, but largely inconsequential for local demography. By contrast, in marine systems, dispersal at regional scales may drive local dynamics, because many species may have large mean dispersal distances. To assess variation in marine dispersal scales, we estimated mean dispersal distances from genetic isolation-by-distance slopes. Estimates ranged widely, from a few meters to hundreds of kilometers. Dispersal differed among taxonomic groups (macroalgae, invertebrates, and fish) and among species in different functional groups (e.g., producers and herbivores). Differences in dispersal scale have important implications for marine community dynamics, reserve design, responses to large-scale perturbations, and evolution of interacting species. To place genetic estimates of marine dispersal in context, we compared them to other measures of dispersal in the ocean and to estimates of dispersal on land. Maximum scales of dispersal by sedentary marine species exceeded maximum estimates of terrestrial plant dispersal by at least one to two orders of magnitude. Direct and genetic estimates of terrestrial plant dispersal were comparable to estimates of marine plant dispersal. Rates of marine macroalgal range expansion, however, far exceeded spread rates of terrestrial plants. Terrestrial plant spread rates were more similar to those of short-dispersing marine organisms that lack secondary dispersal by drifting adults. Genetic estimates of dispersal by different functional groups suggest that herbivores typically disperse much farther than their plant resources both on land and in the sea, although the timing, frequency, and consequences of dispersal may differ in the two systems. Terrestrial herbivores have more flexible dispersal behavior than marine organisms that disperse each generation by planktonic transport of larvae. Our results validate some long-standing views about the greater dispersal potential of species in the ocean, but also highlight the extreme heterogeneity in dispersal scale among marine species. As a result, development of a community perspective on marine connectivity will require consideration of multiple dispersal mechanisms and scales.",
    url = "https://doi.org/10.1890/01-0622",
    doi = "10.1890/01-0622",
    openalex = "W2046753694",
    references = "doi101126science11538249, doi101146annureves15110184000433"
}

Efforts to understand the population dynamics of marine species with planktonic larvae have been stymied by the fact that the larvae recruiting to a location have little chance of originating from that site. Patterns of larval movement and the spatial scale of dispersal are expected to be major forces regulating the dynamics of marine populations and communities. Unfortunately, the scale and predictability of larval dispersal and its regulation by physical circulation remains unknown due largely to the impossibility of measuring dispersal in open marine environments. Here we exploit strong genetic differentiation among marine mussel populations in southwest England to measure larval dispersal among adjoining genetic patches. This approach allows estimates of larval dispersal over relatively great distances. We combine these measurements with results from a high-resolution model of coastal circulation to test the hypothesis that larval dispersal is regulated by physical circulation. We show that larval dispersal typically occurs over distances of ∼30 km but in some cases was at least 64 km. The circulation model accurately predicted general patterns of larval transport between genetic regions, the scale of larval dispersal, and genetic isolation created by physical barriers to circulation. We demonstrate that physical circulation models and genetic measures of larval transport can be coupled to assess the geographic scale of larval dispersal in marine environments.

@article{doi101890020498,
    author = "Gilg, Matthew R. and Hilbish, Thomas J.",
    title = "THE GEOGRAPHY OF MARINE LARVAL DISPERSAL: COUPLING GENETICS WITH FINE-SCALE PHYSICAL OCEANOGRAPHY",
    year = "2003",
    journal = "Ecology",
    abstract = "Efforts to understand the population dynamics of marine species with planktonic larvae have been stymied by the fact that the larvae recruiting to a location have little chance of originating from that site. Patterns of larval movement and the spatial scale of dispersal are expected to be major forces regulating the dynamics of marine populations and communities. Unfortunately, the scale and predictability of larval dispersal and its regulation by physical circulation remains unknown due largely to the impossibility of measuring dispersal in open marine environments. Here we exploit strong genetic differentiation among marine mussel populations in southwest England to measure larval dispersal among adjoining genetic patches. This approach allows estimates of larval dispersal over relatively great distances. We combine these measurements with results from a high-resolution model of coastal circulation to test the hypothesis that larval dispersal is regulated by physical circulation. We show that larval dispersal typically occurs over distances of ∼30 km but in some cases was at least 64 km. The circulation model accurately predicted general patterns of larval transport between genetic regions, the scale of larval dispersal, and genetic isolation created by physical barriers to circulation. We demonstrate that physical circulation models and genetic measures of larval transport can be coupled to assess the geographic scale of larval dispersal in marine environments.",
    url = "https://doi.org/10.1890/02-0498",
    doi = "10.1890/02-0498",
    openalex = "W1982854706",
    references = "eckman1996closing"
}

Life-history parameters were used to estimate the dispersal potential of 1021 marine macroinvertebrates recorded in species lists from 91 sites comprising rocky intertidal, subtidal, kelp forest, sandy beach, and soft-bottom habitats in Washington, Oregon, and California. Mean species richness was significantly greater in the California rocky subtidal habitat. Data on development mode, planktonic larval duration, rafting potential, and adult mobility were compiled, and summaries of the dispersal potentials of taxa within each habitat type were generated and compared. In summary, development mode was known or estimated for 76% of species; larval planktonic duration for 49%; adult mobility for 76%; and rafting potential for 46%. In comparisons of species' life-history traits among habitats, sand-dominated habitats were distinct from rocky habitats. In rocky habitats, ∼42% of species had planktonic feeding larvae, 43% had planktonic nonfeeding larvae, and 15% had nonplanktonic larvae. Sandy intertidal habitats had higher proportions of taxa with nondispersing, nonplanktonic larvae and lower proportions of planktonic feeding and nonfeeding larvae than all other sites. Soft-bottom subtidal communities had the highest proportion of taxa with planktonic feeding development and larvae with planktonic lifespans >30 d. Species in soft-bottom subtidal sites, therefore, have the greatest potential for extensive larval dispersal, whereas species in soft-bottom intertidal sites have the least potential for larval dispersal. In these sites with limited larval dispersal potential, there is greater potential for adult dispersal through adult movement and rafting. These differences in the dispersal potential of larvae and adults suggest that the effect of environmental changes and the effectiveness of reserves may differ between habitats. Conservation methods, including the use of marine reserves, must therefore be tailored to the habitat of interest if effective protection of community resources is to be achieved.

@article{doi1018901051076120030130108dpomii20co2,
    author = "Grantham, Brian A. and Eckert, Ginny L. and Shanks, Alan L.",
    title = "DISPERSAL POTENTIAL OF MARINE INVERTEBRATES IN DIVERSE HABITATS",
    year = "2003",
    journal = "Ecological Applications",
    abstract = "Life-history parameters were used to estimate the dispersal potential of 1021 marine macroinvertebrates recorded in species lists from 91 sites comprising rocky intertidal, subtidal, kelp forest, sandy beach, and soft-bottom habitats in Washington, Oregon, and California. Mean species richness was significantly greater in the California rocky subtidal habitat. Data on development mode, planktonic larval duration, rafting potential, and adult mobility were compiled, and summaries of the dispersal potentials of taxa within each habitat type were generated and compared. In summary, development mode was known or estimated for 76\% of species; larval planktonic duration for 49\%; adult mobility for 76\%; and rafting potential for 46\%. In comparisons of species' life-history traits among habitats, sand-dominated habitats were distinct from rocky habitats. In rocky habitats, ∼42\% of species had planktonic feeding larvae, 43\% had planktonic nonfeeding larvae, and 15\% had nonplanktonic larvae. Sandy intertidal habitats had higher proportions of taxa with nondispersing, nonplanktonic larvae and lower proportions of planktonic feeding and nonfeeding larvae than all other sites. Soft-bottom subtidal communities had the highest proportion of taxa with planktonic feeding development and larvae with planktonic lifespans >30 d. Species in soft-bottom subtidal sites, therefore, have the greatest potential for extensive larval dispersal, whereas species in soft-bottom intertidal sites have the least potential for larval dispersal. In these sites with limited larval dispersal potential, there is greater potential for adult dispersal through adult movement and rafting. These differences in the dispersal potential of larvae and adults suggest that the effect of environmental changes and the effectiveness of reserves may differ between habitats. Conservation methods, including the use of marine reserves, must therefore be tailored to the habitat of interest if effective protection of community resources is to be achieved.",
    url = "https://doi.org/10.1890/1051-0761(2003)013[0108:dpomii]2.0.co;2",
    doi = "10.1890/1051-0761(2003)013[0108:dpomii]2.0.co;2",
    openalex = "W1988491399",
    references = "doi101016s0006320797000815, doi10103845533, doi10103845538, doi101086392950, doi101111j1469185x1983tb00380x, doi1015159780295743240, doi1018901051076119988s79mranbn20co2, doi1018901051076120030130146pgdcat20co2, doi1018901051076120030130159pddats20co2, doi103354meps177269"
}

Marine reserves are quickly gaining popularity as a management option for marine conservation, fisheries, and other human uses of the oceans. Despite the popularity of marine reserves as a management tool, few reserves appear to have been created or designed with an understanding of how reserves affect biological factors or how reserves can be designed to meet biological goals more effectively (e.g., attaining sustainable fish populations). This shortcoming occurs in part because the many studies that have examined the impacts of reserves on marine organisms remain isolated examples or anecdotes; the results of these many studies have not yet been synthesized. Here, I review the empirical work and discuss the theoretical literature to assess the impacts of marine reserves on several biological measures (density, biomass, size of organisms, and diversity), paying particular attention to the role reserve size has in determining those impacts. The results of 89 separate studies show that, on average, with the exception of invertebrate biomass and size, values for all four biological measures are significantly higher inside reserves compared to outside (or after reserve establishment vs. before) when evaluated for both the overall communities and by each functional group within these communities (carnivorous fishes, herbivorous fishes, planktivorous fishes/invertebrate eaters, and invertebrates). Surprisingly, results also show that the relative impacts of reserves, such as the proportional differences in density or biomass, are independent of reserve size, suggesting that the effects of marine reserves increase directly rather than proportionally with the size of a reserve. However, equal relative differences in biological measures between small and large reserves nearly always translate into greater absolute differences for larger reserves, and so larger reserves may be necessary to meet the goals set for marine reserves. The quality of the data in the reviewed studies varied greatly. To improve data quality in the future, whenever possible, studies should take measurements before and after the creation of a reserve, replicate sampling, and include a suite of representative species. Despite the variable quality of the data, the results from this review suggest that nearly any marine habitat can benefit from the implementation of a reserve. Success of a marine reserve, however, will always be judged against the expectations for that reserve, and so we must keep in mind the goals of a reserve in its design, management, and evaluation.

@article{doi1018901051076120030130117tiomrd20co2,
    author = "Halpern, Benjamin S.",
    title = "THE IMPACT OF MARINE RESERVES: DO RESERVES WORK AND DOES RESERVE SIZE MATTER?",
    year = "2003",
    journal = "Ecological Applications",
    abstract = "Marine reserves are quickly gaining popularity as a management option for marine conservation, fisheries, and other human uses of the oceans. Despite the popularity of marine reserves as a management tool, few reserves appear to have been created or designed with an understanding of how reserves affect biological factors or how reserves can be designed to meet biological goals more effectively (e.g., attaining sustainable fish populations). This shortcoming occurs in part because the many studies that have examined the impacts of reserves on marine organisms remain isolated examples or anecdotes; the results of these many studies have not yet been synthesized. Here, I review the empirical work and discuss the theoretical literature to assess the impacts of marine reserves on several biological measures (density, biomass, size of organisms, and diversity), paying particular attention to the role reserve size has in determining those impacts. The results of 89 separate studies show that, on average, with the exception of invertebrate biomass and size, values for all four biological measures are significantly higher inside reserves compared to outside (or after reserve establishment vs. before) when evaluated for both the overall communities and by each functional group within these communities (carnivorous fishes, herbivorous fishes, planktivorous fishes/invertebrate eaters, and invertebrates). Surprisingly, results also show that the relative impacts of reserves, such as the proportional differences in density or biomass, are independent of reserve size, suggesting that the effects of marine reserves increase directly rather than proportionally with the size of a reserve. However, equal relative differences in biological measures between small and large reserves nearly always translate into greater absolute differences for larger reserves, and so larger reserves may be necessary to meet the goals set for marine reserves. The quality of the data in the reviewed studies varied greatly. To improve data quality in the future, whenever possible, studies should take measurements before and after the creation of a reserve, replicate sampling, and include a suite of representative species. Despite the variable quality of the data, the results from this review suggest that nearly any marine habitat can benefit from the implementation of a reserve. Success of a marine reserve, however, will always be judged against the expectations for that reserve, and so we must keep in mind the goals of a reserve in its design, management, and evaluation.",
    url = "https://doi.org/10.1890/1051-0761(2003)013[0117:tiomrd]2.0.co;2",
    doi = "10.1890/1051-0761(2003)013[0117:tiomrd]2.0.co;2",
    openalex = "W2121052692",
    references = "doi101002aqc3270040305, doi101126science11538249"
}

Genetic analyses of marine population structure often find only slight geographic differentiation in species with high dispersal potential. Interpreting the significance of this slight genetic signal has been difficult because even mild genetic structure implies very limited demographic exchange between populations, but slight differentiation could also be due to sampling error. Examination of genetic isolation by distance, in which close populations are more similar than distant ones, has the potential to increase confidence in the significance of slight genetic differentiation. Simulations of one-dimensional stepping stone populations with particular larval dispersal regimes shows that isolation by distance is most obvious when comparing populations separated by 2–5 times the mean larval dispersal distance. Available data on fish and invertebrates can be calibrated with this simulation approach and suggest mean dispersal distances of 25–150 km. Design of marine reserve systems requires an understanding of larval transport in and out of reserves, whether reserves will be self-seeding, whether they will accumulate recruits from surrounding exploited areas, and whether reserve networks can exchange recruits. Direct measurements of mean larval dispersal are needed to understand connectivity in a reserve system, but such measurements are extremely difficult. Genetic patterns of isolation by distance have the potential to add to direct measurement of larval dispersal distance and can help set the appropriate geographic scales on which marine reserve systems will function well.

@article{doi1018901051076120030130146pgdcat20co2,
    author = "Palumbi, Stephen R.",
    title = "POPULATION GENETICS, DEMOGRAPHIC CONNECTIVITY, AND THE DESIGN OF MARINE RESERVES",
    year = "2003",
    journal = "Ecological Applications",
    abstract = "Genetic analyses of marine population structure often find only slight geographic differentiation in species with high dispersal potential. Interpreting the significance of this slight genetic signal has been difficult because even mild genetic structure implies very limited demographic exchange between populations, but slight differentiation could also be due to sampling error. Examination of genetic isolation by distance, in which close populations are more similar than distant ones, has the potential to increase confidence in the significance of slight genetic differentiation. Simulations of one-dimensional stepping stone populations with particular larval dispersal regimes shows that isolation by distance is most obvious when comparing populations separated by 2–5 times the mean larval dispersal distance. Available data on fish and invertebrates can be calibrated with this simulation approach and suggest mean dispersal distances of 25–150 km. Design of marine reserve systems requires an understanding of larval transport in and out of reserves, whether reserves will be self-seeding, whether they will accumulate recruits from surrounding exploited areas, and whether reserve networks can exchange recruits. Direct measurements of mean larval dispersal are needed to understand connectivity in a reserve system, but such measurements are extremely difficult. Genetic patterns of isolation by distance have the potential to add to direct measurement of larval dispersal distance and can help set the appropriate geographic scales on which marine reserve systems will function well.",
    url = "https://doi.org/10.1890/1051-0761(2003)013[0146:pgdcat]2.0.co;2",
    doi = "10.1890/1051-0761(2003)013[0146:pgdcat]2.0.co;2",
    openalex = "W2150850312",
    references = "doi101126science3576198, doi1018901051076120030130108dpomii20co2"
}

Rafting has been inferred as an important dispersal mechanism in the marine environment by many authors. The success of rafting depends critically on the availability of suitable floating substrata. Herein currently available information on floating items that have been reported to carry rafting organisms is summarised. Floating items of biotic origin comprise macroalgae, seeds, wood, other vascular plants, and animal remains. Volcanic pumice (natural) and a diverse array of litter and tar lumps (anthropogenic) are the main floating items of abiotic origin. Macroalgae, wood, and plastic macrolitter cover a wide range of sizes while pumice, microlitter, and tar lumps typically are <10 cm in diameter. The longevity of floating items at the sea surface depends on their origin and likelihood to be destroyed by secondary consumers (in increasing order): nonlignified vascular plants/animal carcasses < macroalgae < driftwood < tar lumps/skeletal remains < plastic litter < volcanic pumice. In general, abiotic substrata have a higher longevity than biotic substrata, but most abiotic items are of no or only limited food value for potential rafters. Macroalgae are most abundant at mid-latitudes of both hemispheres, driftwood is of major importance in northern and tropical waters, and floating seeds appear to be most common in tropical regions. Volcanic pumice can be found at all latitudes but has primarily been reported from the Pacific Ocean. Plastic litter and tar lumps are most abundant near the centres of human population and activities. In some regions of abundant supply or zones of hydrography-driven accumulation, floating items can be extremely abundant, exceeding 1000 items km –2. Temporal supply of floating items is variable, being seasonal for most biotic substrata and highly sporadic for some items such as volcanic pumice. Most reported velocities of floating items are in the range of 0.5–1.0 km h –1, but direct measurements have shown that they occasionally are transported at much faster velocities. Published trajectories of floating items also coincide with the main oceanic currents, even though strong winds may sometimes push them out of the principal current systems. Many studies hint toward floating items to link source regions with coastal sinks, in some cases across long distances and even entire ocean basins. Fossil evidence suggests that rafting has also occurred in palaeooceans. During recent centuries and decades the composition and abundance of floating items in the world’s oceans have been strongly affected by human activities, in particular logging, river and coastline regulation, and most importantly oil exploitation and plastic production. The currently abundant supply and the characteristics of floating items suggest that rafting continues to be an important dispersal mechanism in present-day oceans. 182 M. Thiel & L. Gutow

@incollection{doi1012019780203507810ch6,
    author = "Thiel, Martín and Gutow, Lars",
    title = "The Ecology of Rafting in the Marine Environment. I. the Floating Substrata",
    year = "2004",
    booktitle = "Oceanography and Marine Biology/Oceanography and marine biology - an annual review",
    abstract = "Rafting has been inferred as an important dispersal mechanism in the marine environment by many authors. The success of rafting depends critically on the availability of suitable floating substrata. Herein currently available information on floating items that have been reported to carry rafting organisms is summarised. Floating items of biotic origin comprise macroalgae, seeds, wood, other vascular plants, and animal remains. Volcanic pumice (natural) and a diverse array of litter and tar lumps (anthropogenic) are the main floating items of abiotic origin. Macroalgae, wood, and plastic macrolitter cover a wide range of sizes while pumice, microlitter, and tar lumps typically are <10 cm in diameter. The longevity of floating items at the sea surface depends on their origin and likelihood to be destroyed by secondary consumers (in increasing order): nonlignified vascular plants/animal carcasses < macroalgae < driftwood < tar lumps/skeletal remains < plastic litter < volcanic pumice. In general, abiotic substrata have a higher longevity than biotic substrata, but most abiotic items are of no or only limited food value for potential rafters. Macroalgae are most abundant at mid-latitudes of both hemispheres, driftwood is of major importance in northern and tropical waters, and floating seeds appear to be most common in tropical regions. Volcanic pumice can be found at all latitudes but has primarily been reported from the Pacific Ocean. Plastic litter and tar lumps are most abundant near the centres of human population and activities. In some regions of abundant supply or zones of hydrography-driven accumulation, floating items can be extremely abundant, exceeding 1000 items km –2. Temporal supply of floating items is variable, being seasonal for most biotic substrata and highly sporadic for some items such as volcanic pumice. Most reported velocities of floating items are in the range of 0.5–1.0 km h –1, but direct measurements have shown that they occasionally are transported at much faster velocities. Published trajectories of floating items also coincide with the main oceanic currents, even though strong winds may sometimes push them out of the principal current systems. Many studies hint toward floating items to link source regions with coastal sinks, in some cases across long distances and even entire ocean basins. Fossil evidence suggests that rafting has also occurred in palaeooceans. During recent centuries and decades the composition and abundance of floating items in the world’s oceans have been strongly affected by human activities, in particular logging, river and coastline regulation, and most importantly oil exploitation and plastic production. The currently abundant supply and the characteristics of floating items suggest that rafting continues to be an important dispersal mechanism in present-day oceans. 182 M. Thiel \& L. Gutow",
    url = "https://doi.org/10.1201/9780203507810.ch6",
    doi = "10.1201/9780203507810.ch6",
    openalex = "W67217593",
    references = "doi101111j109583122000tb01257x, eckman1996closing, openalexw3172748047, openalexw565715315"
}

Defining the scale of connectivity, or exchange, among marine populations and determining the factors driving this exchange are pivotal to our understanding of the population dynamics, genetic structure, and biogeography of many coastal species. Using a high-resolution biophysical model for the Caribbean region, we report that typical larval dispersal distances of ecologically relevant magnitudes are on the scale of only 10 to 100 kilometers for a variety of reef fish species. We also show the importance of the early onset of active larval movement mediating the dispersal potential. In addition to self-recruitment, larval import from outside the local area is required to sustain most populations, although these population subsidies are very limited in particular systems. The results reveal distinct regions of population isolation based on larval dispersal that also correspond to genetic and morphological clines observed across a range of marine organisms.

@article{doi101126science1122039,
    author = "Cowen, Robert K. and Paris, Claire B. and Srinivasan, Ashwanth",
    title = "Scaling of Connectivity in Marine Populations",
    year = "2005",
    journal = "Science",
    abstract = "Defining the scale of connectivity, or exchange, among marine populations and determining the factors driving this exchange are pivotal to our understanding of the population dynamics, genetic structure, and biogeography of many coastal species. Using a high-resolution biophysical model for the Caribbean region, we report that typical larval dispersal distances of ecologically relevant magnitudes are on the scale of only 10 to 100 kilometers for a variety of reef fish species. We also show the importance of the early onset of active larval movement mediating the dispersal potential. In addition to self-recruitment, larval import from outside the local area is required to sustain most populations, although these population subsidies are very limited in particular systems. The results reveal distinct regions of population isolation based on larval dispersal that also correspond to genetic and morphological clines observed across a range of marine organisms.",
    url = "https://doi.org/10.1126/science.1122039",
    doi = "10.1126/science.1122039",
    openalex = "W2078992396",
    references = "doi101126science11538249"
}

Larvae have been difficult to study because their small size limits our ability to understand their behavior and the conditions they experience. Questions about larval transport focus largely on (a) where they go [dispersal] and (b) where they come from [connectivity]. Mechanisms of transport have been intensively studied in recent decades. As our ability to identify larval sources develops, the consequences of connectivity are garnering more consideration. Attention to transport and connectivity issues has increased dramatically in the past decade, fueled by changing motivations that now include management of fisheries resources, understanding of the spread of invasive species, conservation through the design of marine reserves, and prediction of climate-change effects. Current progress involves both technological advances and the integration of disciplines and approaches. This review focuses on insights gained from physical modeling, chemical tracking, and genetic approaches. I consider how new findings are motivating paradigm shifts concerning (1) life-history consequences; (2) the openness of marine populations, self-recruitment, and population connectivity; (3) the role of behavior; and (4) the significance of variability in space and time. A challenge for the future will be to integrate methods that address dispersal on short (intragenerational) timescales such as elemental fingerprinting and numerical simulations with those that reflect longer timescales such as gene flow estimates and demographic modeling. Recognition and treatment of the continuum between ecological and evolutionary timescales will be necessary to advance the mechanistic understanding of larval and population dynamics.

@article{doi101093icbicj024,
    author = "Levin, Lisa A.",
    title = "Recent progress in understanding larval dispersal: new directions and digressions",
    year = "2006",
    journal = "Integrative and Comparative Biology",
    abstract = "Larvae have been difficult to study because their small size limits our ability to understand their behavior and the conditions they experience. Questions about larval transport focus largely on (a) where they go [dispersal] and (b) where they come from [connectivity]. Mechanisms of transport have been intensively studied in recent decades. As our ability to identify larval sources develops, the consequences of connectivity are garnering more consideration. Attention to transport and connectivity issues has increased dramatically in the past decade, fueled by changing motivations that now include management of fisheries resources, understanding of the spread of invasive species, conservation through the design of marine reserves, and prediction of climate-change effects. Current progress involves both technological advances and the integration of disciplines and approaches. This review focuses on insights gained from physical modeling, chemical tracking, and genetic approaches. I consider how new findings are motivating paradigm shifts concerning (1) life-history consequences; (2) the openness of marine populations, self-recruitment, and population connectivity; (3) the role of behavior; and (4) the significance of variability in space and time. A challenge for the future will be to integrate methods that address dispersal on short (intragenerational) timescales such as elemental fingerprinting and numerical simulations with those that reflect longer timescales such as gene flow estimates and demographic modeling. Recognition and treatment of the continuum between ecological and evolutionary timescales will be necessary to advance the mechanistic understanding of larval and population dynamics.",
    url = "https://doi.org/10.1093/icb/icj024",
    doi = "10.1093/icb/icj024",
    openalex = "W2097025900",
    references = "doi101016b9780122825057x50015, doi101073pnas82113707, doi10108000785236199010422030, doi101111j1469185x1950tb00585x, doi101111j1469185x1983tb00380x, doi101146annurevecolsys271477, doi1018901051076120030130108dpomii20co2, jablonski1983larval, thorson1950reproductive"
}

@misc{doi101016s0065288107530014,
    author = "Marshall, Dustin J. and Keough, Michael J.",
    title = "The Evolutionary Ecology of Offspring Size in Marine Invertebrates",
    year = "2007",
    booktitle = "Advances in marine biology",
    url = "https://doi.org/10.1016/s0065-2881(07)53001-4",
    doi = "10.1016/s0065-2881(07)53001-4",
    openalex = "W1580484740",
    references = "doi101098rstb19350013, doi1012019781003077831, doi103354meps246153, eckman1996closing"
}

Temperature controls the rate of fundamental biochemical processes and thereby regulates organismal attributes including development rate and survival. The increase in metabolic rate with temperature explains substantial among-species variation in life-history traits, population dynamics, and ecosystem processes. Temperature can also cause variability in metabolic rate within species. Here, we compare the effect of temperature on a key component of marine life cycles among a geographically and taxonomically diverse group of marine fish and invertebrates. Although innumerable lab studies document the negative effect of temperature on larval development time, little is known about the generality versus taxon-dependence of this relationship. We present a unified, parameterized model for the temperature dependence of larval development in marine animals. Because the duration of the larval period is known to influence larval dispersal distance and survival, changes in ocean temperature could have a direct and predictable influence on population connectivity, community structure, and regional-to-global scale patterns of biodiversity.

@article{doi101073pnas0603422104,
    author = "O’Connor, Mary I. and Bruno, John F. and Gaines, Steven D. and Halpern, Benjamin S. and Lester, Sarah E. and Kinlan, Brian P. and Weiss, Jack M.",
    title = "Temperature control of larval dispersal and the implications for marine ecology, evolution, and conservation",
    year = "2007",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Temperature controls the rate of fundamental biochemical processes and thereby regulates organismal attributes including development rate and survival. The increase in metabolic rate with temperature explains substantial among-species variation in life-history traits, population dynamics, and ecosystem processes. Temperature can also cause variability in metabolic rate within species. Here, we compare the effect of temperature on a key component of marine life cycles among a geographically and taxonomically diverse group of marine fish and invertebrates. Although innumerable lab studies document the negative effect of temperature on larval development time, little is known about the generality versus taxon-dependence of this relationship. We present a unified, parameterized model for the temperature dependence of larval development in marine animals. Because the duration of the larval period is known to influence larval dispersal distance and survival, changes in ocean temperature could have a direct and predictable influence on population connectivity, community structure, and regional-to-global scale patterns of biodiversity.",
    url = "https://doi.org/10.1073/pnas.0603422104",
    doi = "10.1073/pnas.0603422104",
    openalex = "W2157367008",
    references = "doi101016b9780122825057x50015, doi101086381872, doi101111j1469185x1950tb00585x, doi101146annureves16110185002011, thorson1950reproductive"
}

Connectivity, or the exchange of individuals among marine populations, is a central topic in marine ecology. For most benthic marine species with complex life cycles, this exchange occurs primarily during the pelagic larval stage. The small size of larvae coupled with the vast and complex fluid environment they occupy hamper our ability to quantify dispersal and connectivity. Evidence from direct and indirect approaches using geochemical and genetic techniques suggests that populations range from fully open to fully closed. Understanding the biophysical processes that contribute to observed dispersal patterns requires integrated interdisciplinary approaches that incorporate high-resolution biophysical modeling and empirical data. Further, differential postsettlement survival of larvae may add complexity to measurements of connectivity. The degree to which populations self recruit or receive subsidy from other populations has consequences for a number of fundamental ecological processes that affect population regulation and persistence. Finally, a full understanding of population connectivity has important applications for management and conservation.

@article{doi101146annurevmarine010908163757,
    author = "Cowen, Robert K. and Sponaugle, Su",
    title = "Larval Dispersal and Marine Population Connectivity",
    year = "2008",
    journal = "Annual Review of Marine Science",
    abstract = "Connectivity, or the exchange of individuals among marine populations, is a central topic in marine ecology. For most benthic marine species with complex life cycles, this exchange occurs primarily during the pelagic larval stage. The small size of larvae coupled with the vast and complex fluid environment they occupy hamper our ability to quantify dispersal and connectivity. Evidence from direct and indirect approaches using geochemical and genetic techniques suggests that populations range from fully open to fully closed. Understanding the biophysical processes that contribute to observed dispersal patterns requires integrated interdisciplinary approaches that incorporate high-resolution biophysical modeling and empirical data. Further, differential postsettlement survival of larvae may add complexity to measurements of connectivity. The degree to which populations self recruit or receive subsidy from other populations has consequences for a number of fundamental ecological processes that affect population regulation and persistence. Finally, a full understanding of population connectivity has important applications for management and conservation.",
    url = "https://doi.org/10.1146/annurev.marine.010908.163757",
    doi = "10.1146/annurev.marine.010908.163757",
    openalex = "W2140618008",
    references = "doi1010160169534789900086, doi101046j14610248200300530x, doi101073pnas82113707, doi101093icbicj028, doi101126science11538249, doi101146annurevecolsys271477, doi101146annurevmarine010908163708, doi1018900012965820020831490prhcac20co2"
}

Chemicals with the potential to damage DNA are increasingly present in the marine environment; yet our understanding of the long-term consequences of DNA damage for populations remains limited. We explore the impact of paternal genotoxin exposure on the reproductive biology of two ecologically important free-spawning marine invertebrates: the polychaete Arenicola marina and the mussel Mytilus edulis. Males were exposed in vivo for 72 h to methyl methanesulfonate and benzo(a)pyrene and the impact on somatic cells and sperm assessed using the Comet assay. A strong correlation between DNA damage in somatic cells and sperm was observed after 24 h exposure (P < 0.001). Recovery in sperm was significantly lower than in coelomocytes after 72 h. The fertilization success of DNA-damaged sperm was unaffected, but a significant percentage of embryos derived from sperm with induced DNA damage exhibited severe developmental abnormalities within 24 h of fertilization with potential long-term consequences for population success. Further research is required to determine the mechanism by which paternal DNA damage causes disruption of development at this early stage.

@article{doi101021es802215d,
    author = "Lewis, Ceri and Galloway, Tamara S.",
    title = "Reproductive Consequences of Paternal Genotoxin Exposure in Marine Invertebrates",
    year = "2009",
    journal = "Environmental Science \& Technology",
    abstract = "Chemicals with the potential to damage DNA are increasingly present in the marine environment; yet our understanding of the long-term consequences of DNA damage for populations remains limited. We explore the impact of paternal genotoxin exposure on the reproductive biology of two ecologically important free-spawning marine invertebrates: the polychaete Arenicola marina and the mussel Mytilus edulis. Males were exposed in vivo for 72 h to methyl methanesulfonate and benzo(a)pyrene and the impact on somatic cells and sperm assessed using the Comet assay. A strong correlation between DNA damage in somatic cells and sperm was observed after 24 h exposure (P < 0.001). Recovery in sperm was significantly lower than in coelomocytes after 72 h. The fertilization success of DNA-damaged sperm was unaffected, but a significant percentage of embryos derived from sperm with induced DNA damage exhibited severe developmental abnormalities within 24 h of fertilization with potential long-term consequences for population success. Further research is required to determine the mechanism by which paternal DNA damage causes disruption of development at this early stage.",
    url = "https://doi.org/10.1021/es802215d",
    doi = "10.1021/es802215d",
    openalex = "W2058307126"
}

The ability of miniscule larvae to control their fate and replenish populations in dynamic marine environments has been a long-running topic of debate of central importance for managing resources and understanding the ecology and evolution of life in the sea. Larvae are considered to be highly susceptible to offshore transport in productive upwelling regions, thereby increasing dispersal, limiting onshore recruitment, and reducing the intensity of community interactions. We show that 45 species of nearshore crustaceans were not transported far offshore in a recruitment-limited region characterized by strong upwelling. To the contrary, 92% of these larvae remained within 6 km from shore in high densities throughout development along two transects sampled four times during the peak upwelling season. Larvae of most species remained nearshore by remaining below a shallow Ekman layer of seaward-flowing surface waters throughout development. Larvae of other species migrated farther offshore by occurring closer to the surface early in development. Postlarvae evidently returned to nearshore adult habitats either by descending to shoreward-flowing upwelled waters or rising to the sea surface where they can be transported shoreward by wind relaxation events or internal waves. Thus wind-driven offshore transport should not limit recruitment, even in strong upwelling regions, and larvae are more likely to recruit closer to natal populations than is widely believed. This study poses a new challenge to determine the true cause and extent of recruitment limitation for a more diverse array of species along upwelling coasts, and thus to further advance our understanding of the connectivity, dynamics, and structure of coastal populations.

@article{doi1018900815501,
    author = "Morgan, Steven G. and Fisher, Jennifer L. and Miller, Seth H. and McAfee, Skyli and Largier, John L.",
    title = "Nearshore larval retention in a region of strong upwelling and recruitment limitation",
    year = "2009",
    journal = "Ecology",
    abstract = "The ability of miniscule larvae to control their fate and replenish populations in dynamic marine environments has been a long-running topic of debate of central importance for managing resources and understanding the ecology and evolution of life in the sea. Larvae are considered to be highly susceptible to offshore transport in productive upwelling regions, thereby increasing dispersal, limiting onshore recruitment, and reducing the intensity of community interactions. We show that 45 species of nearshore crustaceans were not transported far offshore in a recruitment-limited region characterized by strong upwelling. To the contrary, 92\% of these larvae remained within 6 km from shore in high densities throughout development along two transects sampled four times during the peak upwelling season. Larvae of most species remained nearshore by remaining below a shallow Ekman layer of seaward-flowing surface waters throughout development. Larvae of other species migrated farther offshore by occurring closer to the surface early in development. Postlarvae evidently returned to nearshore adult habitats either by descending to shoreward-flowing upwelled waters or rising to the sea surface where they can be transported shoreward by wind relaxation events or internal waves. Thus wind-driven offshore transport should not limit recruitment, even in strong upwelling regions, and larvae are more likely to recruit closer to natal populations than is widely believed. This study poses a new challenge to determine the true cause and extent of recruitment limitation for a more diverse array of species along upwelling coasts, and thus to further advance our understanding of the connectivity, dynamics, and structure of coastal populations.",
    url = "https://doi.org/10.1890/08-1550.1",
    doi = "10.1890/08-1550.1",
    openalex = "W2091990001",
    references = "doi101016s0065288104470023, young1990larval"
}

Population connectivity plays significant roles on both evolutionary and ecological time-scales; however, quantifying the magnitude and pattern of exchange between populations of marine organisms is hindered by the difficulty of tracking the trajectory and fate of propagules. We explored biophysical correlates of population substructure to determine how well pelagic larval duration (PLD) correlates with population genetic estimates of connectivity in a sample of 300 published studies drawn pseudo-randomly from about 1600 hits on electronic searches. In direct contrast to the general expectation of a strong correlation, we find that average PLD is poorly correlated (r 2 < 0.1) with genetic structure (F ST). Furthermore, even this weak correlation is anchored by non-pelagic dispersal, because removal of the zero PLD class (direct developers) from the analysis resulted in a non-significant relationship between F ST and PLD. For species in which minimum, maximum, and mean PLDs were available, it is noteworthy that both minimum and maximum PLDs are better correlated with F ST than the mean larval duration, which has been used in all such previous studies. A 3-way AN-COVA reveals that genetic marker class (allozymes, microsatellites, and mitochondrial DNA sequences), as opposed to habitat or swimming ability, explain most of the variation in F ST (F = 7.113, df = 2, p = 0.001), with higher values of F ST obtained from mtDNA than with either microsatellites or allozymes (which were not significantly different). Our meta-analysis refutes recent reviews and conventional wisdom that PLD is a good predictor of the magnitude of gene flow and geographic scale of population structure in marine systems.

@article{doi103354meps08287,
    author = "Weersing, K. and Toonen, Robert J.",
    title = "Population genetics, larval dispersal, and connectivity in marine systems",
    year = "2009",
    journal = "Marine Ecology Progress Series",
    abstract = "Population connectivity plays significant roles on both evolutionary and ecological time-scales; however, quantifying the magnitude and pattern of exchange between populations of marine organisms is hindered by the difficulty of tracking the trajectory and fate of propagules. We explored biophysical correlates of population substructure to determine how well pelagic larval duration (PLD) correlates with population genetic estimates of connectivity in a sample of 300 published studies drawn pseudo-randomly from about 1600 hits on electronic searches. In direct contrast to the general expectation of a strong correlation, we find that average PLD is poorly correlated (r 2 < 0.1) with genetic structure (F ST). Furthermore, even this weak correlation is anchored by non-pelagic dispersal, because removal of the zero PLD class (direct developers) from the analysis resulted in a non-significant relationship between F ST and PLD. For species in which minimum, maximum, and mean PLDs were available, it is noteworthy that both minimum and maximum PLDs are better correlated with F ST than the mean larval duration, which has been used in all such previous studies. A 3-way AN-COVA reveals that genetic marker class (allozymes, microsatellites, and mitochondrial DNA sequences), as opposed to habitat or swimming ability, explain most of the variation in F ST (F = 7.113, df = 2, p = 0.001), with higher values of F ST obtained from mtDNA than with either microsatellites or allozymes (which were not significantly different). Our meta-analysis refutes recent reviews and conventional wisdom that PLD is a good predictor of the magnitude of gene flow and geographic scale of population structure in marine systems.",
    url = "https://doi.org/10.3354/meps08287",
    doi = "10.3354/meps08287",
    openalex = "W2104398796",
    references = "doi101038sjhdy6884960, doi101046j1365294x200302063x, doi101086392950, doi101093jhered895438, doi101111j1365294x200803887x, doi101111j146918091949tb02451x, doi101126science1122039, doi101126science2875454857, doi1018901051076120030130146pgdcat20co2, doi1023072531471"
}

@article{lewis2010sperm,
    author = "Lewis, Ceri and Galloway, Tamara",
    title = "Sperm toxicity and the reproductive ecology of marine invertebrates",
    year = "2010",
    journal = "Integrated Environmental Assessment and Management",
    url = "https://doi.org/10.1002/ieam.23",
    doi = "10.1002/ieam.23",
    number = "1",
    openalex = "W2089335479",
    pages = "188-190",
    volume = "6",
    references = "doi101016jaquatox200808001, doi101016jcub200806015, doi101016s0065288107530014, doi101021es802215d, doi101038432048a, doi103354meps333051"
}

@article{doi101016jmarenvres201110004,
    author = "Byrne, Maria",
    title = "Global change ecotoxicology: Identification of early life history bottlenecks in marine invertebrates, variable species responses and variable experimental approaches",
    year = "2011",
    journal = "Marine Environmental Research",
    url = "https://doi.org/10.1016/j.marenvres.2011.10.004",
    doi = "10.1016/j.marenvres.2011.10.004",
    openalex = "W2014903749",
    references = "doi101038nature02808, doi101038nature04095, doi101111j14610248200500871x, doi101111j14610248200801253x, doi101111j14610248201001518x, doi101126science1097329, doi101126science28754612225, doi101146annurevmarine010908163834, doi101242jeb037473, doi101242jeb037523, doi103354meps177269"
}

Biologists have long sought to identify and explain patterns in the diverse array of marine life histories. The most famous speculation about such patterns is Gunnar Thorson's suggestion that species producing planktonic larvae are rarer at higher latitudes (Thorson's rule). Although some elements of Thorson's rule have proven incorrect, other elements remain untested. With a wealth of new life-history data, statistical approaches, and remote-sensing technology, new insights into marine reproduction can be generated. We gathered life-history data for more than 1,000 marine invertebrates and examined patterns in the prevalence of different life histories. Systematic patterns in marine life histories exist at a range of scales, some of which support Thorson, whereas others suggest previously unrecognized relationships between the marine environment and the life histories of marine invertebrates. Overall, marine life histories covary strongly with temperature and local ocean productivity, and different regions should be managed accordingly.

@article{doi101146annurevecolsys102710145004,
    author = "Marshall, Dustin J. and Krug, Patrick J. and Kupriyanova, Elena K. and Byrne, Maria and Emlet, Richard B.",
    title = "The Biogeography of Marine Invertebrate Life Histories",
    year = "2011",
    journal = "Annual Review of Ecology Evolution and Systematics",
    abstract = "Biologists have long sought to identify and explain patterns in the diverse array of marine life histories. The most famous speculation about such patterns is Gunnar Thorson's suggestion that species producing planktonic larvae are rarer at higher latitudes (Thorson's rule). Although some elements of Thorson's rule have proven incorrect, other elements remain untested. With a wealth of new life-history data, statistical approaches, and remote-sensing technology, new insights into marine reproduction can be generated. We gathered life-history data for more than 1,000 marine invertebrates and examined patterns in the prevalence of different life histories. Systematic patterns in marine life histories exist at a range of scales, some of which support Thorson, whereas others suggest previously unrecognized relationships between the marine environment and the life histories of marine invertebrates. Overall, marine life histories covary strongly with temperature and local ocean productivity, and different regions should be managed accordingly.",
    url = "https://doi.org/10.1146/annurev-ecolsys-102710-145004",
    doi = "10.1146/annurev-ecolsys-102710-145004",
    openalex = "W2133547121",
    references = "doi103354meps08287, young1990larval"
}

Most insects have a complex life cycle with ecologically different larval and adult stages. We present an ontogenetic perspective to analyze and summarize the complex life cycle of Odonata within an evolutionary ecology framework. Morphological, physiological, and behavioral pathways that generate carry-over effects across the aquatic egg and larval stages and the terrestrial adult stage are identified. We also highlight several mechanisms that can decouple life stages including compensatory mechanisms at the larval and adult stages, stressful and stochastic events during metamorphosis, and stressful environmental conditions at the adult stage that may overrule effects of environmental conditions in the preceding stage. We consider the implications of these findings for the evolution, selection, and fitness of odonates; underline the role of the identified numerical and carry-over effects in shaping population and metapopulation dynamics and the community structure across habitat boundaries; and discuss implications for applied conservation issues.

@article{doi101146annurevento120710100557,
    author = "Stoks, Robby and Córdoba‐Aguilar, Alex",
    title = "Evolutionary Ecology of Odonata: A Complex Life Cycle Perspective",
    year = "2011",
    journal = "Annual Review of Entomology",
    abstract = "Most insects have a complex life cycle with ecologically different larval and adult stages. We present an ontogenetic perspective to analyze and summarize the complex life cycle of Odonata within an evolutionary ecology framework. Morphological, physiological, and behavioral pathways that generate carry-over effects across the aquatic egg and larval stages and the terrestrial adult stage are identified. We also highlight several mechanisms that can decouple life stages including compensatory mechanisms at the larval and adult stages, stressful and stochastic events during metamorphosis, and stressful environmental conditions at the adult stage that may overrule effects of environmental conditions in the preceding stage. We consider the implications of these findings for the evolution, selection, and fitness of odonates; underline the role of the identified numerical and carry-over effects in shaping population and metapopulation dynamics and the community structure across habitat boundaries; and discuss implications for applied conservation issues.",
    url = "https://doi.org/10.1146/annurev-ento-120710-100557",
    doi = "10.1146/annurev-ento-120710-100557",
    openalex = "W2157802851",
    references = "doi101016jtree200404009, doi101038nature03962, doi101093icbicj028, doi101093oso97801951116370010001, doi101111j14610248200701081x, doi101111j1469185x200900101x, doi101126science1154082, doi101146annureves11110180000435, doi103354meps177269, openalexw2082612019"
}

Global warming and increased atmospheric CO2 are causing the oceans to warm, decrease in pH and become hypercapnic. These stressors have deleterious impacts on marine invertebrates. Increasing temperature has a pervasive stimulatory effect on metabolism until lethal levels are reached, whereas hypercapnia has a narcotic effect. Ocean acidi™cation is a major threat to calcifying larvae because it decreases availability of the carbonate ions required for skeletogenesis and also exerts a direct pH effect on physiology. Marine invertebrate propagules live in a multistressor world and climate change stressors are adding to the mix. Ocean pH, pCO2 and CaCO3 covary and will change simultaneously with temperature, challenging our ability to predict future outcomes for marine biota. To address questions of future vulnerabilities, data on the thermo-and pH/pCO2 tolerance of fertilization and development in marine invertebrates are reviewed in the context of the change in the oceans that are forecast to occur over the next 100-200 years. Gametes and fertilization in many invertebrates exhibit a broad tolerance to warming and acidi™cation beyond stressor values projected for 2100. Available data show that all development stages are highly sensitive to warming. Larvae may be particularly sensitive to acidi™cation/hypercapnia. Embryos that develop through the bottleneck of mortality due to warming may succumb as larvae to acidi™cation. Early juveniles may be vulnerable to skeletal dissolution, although warming may diminish the negative impact of acidi™- cation on calci™cation. The effects of climate change stressors and their interaction differ among life history stages and species. Multistressor experiments show that if thermal thresholds are breached, embryos may not reach the calcifying stage. If the bottleneck for species persistence is embryonic thermotolerance, then the question of compromised calici™cation due to acidi™cation may not be relevant. Our limited knowledge of the interactive effects of climate change stressors is a major knowledge gap. Although climate change is deleterious for development in a broad range of marine invertebrates, some species and regional faunas will be more resilient than others. This has implications for persistence, faunal shifts, species invasions and community function in a changing ocean.

@incollection{doi101201b110093,
    author = "Stella, Jessica and Pratchett, Morgan S. and Hutchings, Pat and Jones, Geoffrey P.",
    title = "Coral-associated invertebrates",
    year = "2011",
    booktitle = "Oceanography and Marine Biology/Oceanography and marine biology - an annual review",
    abstract = "Global warming and increased atmospheric CO2 are causing the oceans to warm, decrease in pH and become hypercapnic. These stressors have deleterious impacts on marine invertebrates. Increasing temperature has a pervasive stimulatory effect on metabolism until lethal levels are reached, whereas hypercapnia has a narcotic effect. Ocean acidi™cation is a major threat to calcifying larvae because it decreases availability of the carbonate ions required for skeletogenesis and also exerts a direct pH effect on physiology. Marine invertebrate propagules live in a multistressor world and climate change stressors are adding to the mix. Ocean pH, pCO2 and CaCO3 covary and will change simultaneously with temperature, challenging our ability to predict future outcomes for marine biota. To address questions of future vulnerabilities, data on the thermo-and pH/pCO2 tolerance of fertilization and development in marine invertebrates are reviewed in the context of the change in the oceans that are forecast to occur over the next 100-200 years. Gametes and fertilization in many invertebrates exhibit a broad tolerance to warming and acidi™cation beyond stressor values projected for 2100. Available data show that all development stages are highly sensitive to warming. Larvae may be particularly sensitive to acidi™cation/hypercapnia. Embryos that develop through the bottleneck of mortality due to warming may succumb as larvae to acidi™cation. Early juveniles may be vulnerable to skeletal dissolution, although warming may diminish the negative impact of acidi™- cation on calci™cation. The effects of climate change stressors and their interaction differ among life history stages and species. Multistressor experiments show that if thermal thresholds are breached, embryos may not reach the calcifying stage. If the bottleneck for species persistence is embryonic thermotolerance, then the question of compromised calici™cation due to acidi™cation may not be relevant. Our limited knowledge of the interactive effects of climate change stressors is a major knowledge gap. Although climate change is deleterious for development in a broad range of marine invertebrates, some species and regional faunas will be more resilient than others. This has implications for persistence, faunal shifts, species invasions and community function in a changing ocean.",
    url = "https://doi.org/10.1201/b11009-3",
    doi = "10.1201/b11009-3",
    openalex = "W2262378901",
    references = "doi10100703873072065, doi101007s1064601004636, doi101016b9780122825019500065, doi101016jtree200308007, doi101038019118a0, doi101038416389a, doi101038nature04095, doi10108000785236199010422030, doi101111j175348871981tb06752x, doi101126science1059199, doi101126science1149345, doi101126science1152509, doi101126science1924238461, doi101126science19943351302, doi101146annurevecolsys37091305110149, doi101371journalpone0005661, doi1023071942565, doi1023073545850, doi103354meps177269, doi105670oceanog2009101, openalexw2173200745, openalexw2297370949"
}

Understanding connectivity remains a fundamental challenge to marine ecology due to technical limitations of tracking larval dispersal. Marine population genetic analyses are often used to make inferences about the scale of population connectivity. For species with a larval phase, pelagic larval duration (PLD) is assumed to influence the scale of connectivity. If PLD and genetic metrics are reliable proxies of connectivity, the 2 should be well correlated. Previous tests report conflicting results, with many reports that global F ST (Wright's fixation index) correlates poorly with PLD, and one very high correlation of isolation-by-distance (IBD) slope, which is derived from F ST, with PLD. First we clarify the expectations for the performance of these different proxies in light of the latest understanding of larval dispersal dynamics. We then test the hypothesis that IBD slope may be a more robust correlate with dispersal scale than global F ST with a new dataset of recent marine genetic studies. Re-evaluation of previously published and new datasets revealed a consistent, moderate fit (R 2 ~0.30) between genetic and PLD proxies of dispersal (using either IBD slope or global F ST), with significant improvement for small-scale (< 650 km) studies (R 2 = 0.50), and important effects of marker type. Significant effects of number of individuals and number of populations sampled on the genetic metrics in our dataset suggest a common need for more robust sampling designs. These results synchronize previous studies on this topic and provide validation that PLD and genetic metrics typically reflect scales of dispersal, as intended, at least when sampling design is robust.

@article{doi103354meps09238,
    author = "Selkoe, KA and Toonen, Robert J.",
    title = "Marine connectivity: a new look at pelagic larval duration and genetic metrics of dispersal",
    year = "2011",
    journal = "Marine Ecology Progress Series",
    abstract = "Understanding connectivity remains a fundamental challenge to marine ecology due to technical limitations of tracking larval dispersal. Marine population genetic analyses are often used to make inferences about the scale of population connectivity. For species with a larval phase, pelagic larval duration (PLD) is assumed to influence the scale of connectivity. If PLD and genetic metrics are reliable proxies of connectivity, the 2 should be well correlated. Previous tests report conflicting results, with many reports that global F ST (Wright's fixation index) correlates poorly with PLD, and one very high correlation of isolation-by-distance (IBD) slope, which is derived from F ST, with PLD. First we clarify the expectations for the performance of these different proxies in light of the latest understanding of larval dispersal dynamics. We then test the hypothesis that IBD slope may be a more robust correlate with dispersal scale than global F ST with a new dataset of recent marine genetic studies. Re-evaluation of previously published and new datasets revealed a consistent, moderate fit (R 2 \textasciitilde 0.30) between genetic and PLD proxies of dispersal (using either IBD slope or global F ST), with significant improvement for small-scale (< 650 km) studies (R 2 = 0.50), and important effects of marker type. Significant effects of number of individuals and number of populations sampled on the genetic metrics in our dataset suggest a common need for more robust sampling designs. These results synchronize previous studies on this topic and provide validation that PLD and genetic metrics typically reflect scales of dispersal, as intended, at least when sampling design is robust.",
    url = "https://doi.org/10.3354/meps09238",
    doi = "10.3354/meps09238",
    openalex = "W2313761567",
    references = "doi101371journalpone0008594, doi103354meps08287"
}

Connectivity among marine populations is critical for persistence of metapopulations, coping with climate change, and determining the geographic distribution of species. The influence of pelagic larval duration (PLD) on connectivity has been studied extensively, but relatively little is known about the influence of other biological parameters, such as the survival and behavior of larvae, and the fecundity of adults, on population connectivity. Furthermore, the interaction between the seascape (habitat structure and currents) and these biological parameters is unclear. We explore these interactions using a biophysical model of larval dispersal across the Indo-Pacific. We describe an approach that quantifies geographic patterns of connectivity from demographically relevant to evolutionarily significant levels across a range of species. We predict that at least 95% of larval settlement occurs within 155 km of the source population and within 13 days irrespective of the species' life history, yet long-distant connections remain likely. Self-recruitment is primarily driven by the local oceanography, larval mortality, and the larval precompetency period, whereas broad-scale connectivity is strongly influenced by reproductive output (abundance and fecundity of adults) and the length of PLD. The networks we have created are geographically explicit models of marine connectivity that define dispersal corridors, barriers, and the emergent structure of marine populations. These models provide hypotheses for empirical testing.

@article{doi101093icbics101,
    author = "Treml, Eric A. and Roberts, Jason J. and Chao, Yi and Halpin, Patrick N. and Possingham, Hugh P. and Riginos, Cynthia",
    title = "Reproductive Output and Duration of the Pelagic Larval Stage Determine Seascape-Wide Connectivity of Marine Populations",
    year = "2012",
    journal = "Integrative and Comparative Biology",
    abstract = "Connectivity among marine populations is critical for persistence of metapopulations, coping with climate change, and determining the geographic distribution of species. The influence of pelagic larval duration (PLD) on connectivity has been studied extensively, but relatively little is known about the influence of other biological parameters, such as the survival and behavior of larvae, and the fecundity of adults, on population connectivity. Furthermore, the interaction between the seascape (habitat structure and currents) and these biological parameters is unclear. We explore these interactions using a biophysical model of larval dispersal across the Indo-Pacific. We describe an approach that quantifies geographic patterns of connectivity from demographically relevant to evolutionarily significant levels across a range of species. We predict that at least 95\% of larval settlement occurs within 155 km of the source population and within 13 days irrespective of the species' life history, yet long-distant connections remain likely. Self-recruitment is primarily driven by the local oceanography, larval mortality, and the larval precompetency period, whereas broad-scale connectivity is strongly influenced by reproductive output (abundance and fecundity of adults) and the length of PLD. The networks we have created are geographically explicit models of marine connectivity that define dispersal corridors, barriers, and the emergent structure of marine populations. These models provide hypotheses for empirical testing.",
    url = "https://doi.org/10.1093/icb/ics101",
    doi = "10.1093/icb/ics101",
    openalex = "W2141985712",
    references = "doi103354meps08287"
}

Abstract Aim Pleistocene glacial cycles reduced global sea level by up to 130 m below present levels. These changes had profound impacts on coastal marine life, including a reduction of habitable area, changes in ocean currents, and shifts in water column thermal dynamics. We provide a comprehensive review of the impact of glacial sea‐level changes during the Pleistocene on tropical coastal marine life and a set of maps showing how coastlines worldwide changed during periods of low sea levels. Location We focused on coastal marine taxa within tropical latitudes, with deeper coverage of the world's major coral reef biogeographical provinces. Methods We examined recent and historical literature that alluded to the effects of Pleistocene sea‐level fluctuations in a variety of common marine clades. Data for shelf habitat area and map construction were obtained from the NOAA ETOPO 1 database, with final manipulations carried out in Adobe Illustrator CS 6. Results Drops in sea level led to a decrease in available coastal habitat and fragmented populations in many taxa, potentially resulting in high population genetic structuring. Habitable shelf area during sea‐level lows was reduced as much as 92% from present‐day values in some regions. Genetic evidence of population bottlenecks can be seen in many coastal marine taxa worldwide. Main conclusions Pleistocene sea‐level fluctuations seem to be linked to population bottlenecks worldwide, and influenced connections among populations separated by barriers that are affected by sea levels. Despite decreased habitat availability, very few species became extinct, and several species may have been formed due to restrictions in water (and consequently larval) flow between regions that are now connected. A variety of interdisciplinary studies have significantly increased our understanding of how Pleistocene sea‐level changes have shaped the marine landscape that we see today.

@article{doi101111jbi12416,
    author = "Ludt, William B. and Rocha, Luiz A.",
    title = "Shifting seas: the impacts of Pleistocene sea‐level fluctuations on the evolution of tropical marine taxa",
    year = "2014",
    journal = "Journal of Biogeography",
    abstract = "Abstract Aim Pleistocene glacial cycles reduced global sea level by up to 130 m below present levels. These changes had profound impacts on coastal marine life, including a reduction of habitable area, changes in ocean currents, and shifts in water column thermal dynamics. We provide a comprehensive review of the impact of glacial sea‐level changes during the Pleistocene on tropical coastal marine life and a set of maps showing how coastlines worldwide changed during periods of low sea levels. Location We focused on coastal marine taxa within tropical latitudes, with deeper coverage of the world's major coral reef biogeographical provinces. Methods We examined recent and historical literature that alluded to the effects of Pleistocene sea‐level fluctuations in a variety of common marine clades. Data for shelf habitat area and map construction were obtained from the NOAA ETOPO 1 database, with final manipulations carried out in Adobe Illustrator CS 6. Results Drops in sea level led to a decrease in available coastal habitat and fragmented populations in many taxa, potentially resulting in high population genetic structuring. Habitable shelf area during sea‐level lows was reduced as much as 92\% from present‐day values in some regions. Genetic evidence of population bottlenecks can be seen in many coastal marine taxa worldwide. Main conclusions Pleistocene sea‐level fluctuations seem to be linked to population bottlenecks worldwide, and influenced connections among populations separated by barriers that are affected by sea levels. Despite decreased habitat availability, very few species became extinct, and several species may have been formed due to restrictions in water (and consequently larval) flow between regions that are now connected. A variety of interdisciplinary studies have significantly increased our understanding of how Pleistocene sea‐level changes have shaped the marine landscape that we see today.",
    url = "https://doi.org/10.1111/jbi.12416",
    doi = "10.1111/jbi.12416",
    openalex = "W1975576679",
    references = "doi103354meps08287"
}

Population connectivity refers to the exchange of individuals among populations: it affects gene flow, regulates population size and function, and mitigates recovery from natural or anthropogenic disturbances. Many populations in the deep sea are spatially fragmented, and will become more so with increasing resource exploitation. Understanding population connectivity is critical for spatial management. For most benthic species, connectivity is achieved by the planktonic larval stage, and larval dispersal is, in turn, regulated by complex interactions between biological and oceanographic processes. Coupled biophysical models, incorporating ocean circulation and biological traits, such as planktonic larval duration (PLD), have been used to estimate population connectivity and generate spatial management plans in coastal and shallow waters. In the deep sea, knowledge gaps in both the physical and biological components are delaying the effective use of this approach. Here, we review the current efforts in conservation in the deep sea and evaluate (1) the relevance of using larval dispersal in the design of marine protected areas and (2) the application of biophysical models in the study of population connectivity. Within biophysical models, PLD can be used to estimate dispersal distance. We propose that a PLD that guarantees a minimum dispersal distance for a wide range of species should be used in the planning of marine protected areas in the deep sea. Based on a review of data on species found at depths >200 m, a PLD of 35 and 69 days ensures a minimum distance for 50 and 75%, respectively, of eurybathic and deep-sea species. We note that more data are required to enhance accuracy and address the high variability in PLD between and within taxonomic groups, limiting generalizations that are often appealing to decision-makers. Given the imminent expansion of resource exploitation in the deep sea, data relevant to spatial management are needed urgently.

@article{doi103389fmars201500006,
    author = "Hilário, Ana and Meta×as, Anna and Gaudron, Sylvie M. and Howell, Kerry L. and Mercier, Annie and Mestre, Nélia C. and Ross, Rebecca E. and Thurnherr, Andreas M. and Young, Craig M.",
    title = "Estimating dispersal distance in the deep sea: challenges and applications to marine reserves",
    year = "2015",
    journal = "Frontiers in Marine Science",
    abstract = "Population connectivity refers to the exchange of individuals among populations: it affects gene flow, regulates population size and function, and mitigates recovery from natural or anthropogenic disturbances. Many populations in the deep sea are spatially fragmented, and will become more so with increasing resource exploitation. Understanding population connectivity is critical for spatial management. For most benthic species, connectivity is achieved by the planktonic larval stage, and larval dispersal is, in turn, regulated by complex interactions between biological and oceanographic processes. Coupled biophysical models, incorporating ocean circulation and biological traits, such as planktonic larval duration (PLD), have been used to estimate population connectivity and generate spatial management plans in coastal and shallow waters. In the deep sea, knowledge gaps in both the physical and biological components are delaying the effective use of this approach. Here, we review the current efforts in conservation in the deep sea and evaluate (1) the relevance of using larval dispersal in the design of marine protected areas and (2) the application of biophysical models in the study of population connectivity. Within biophysical models, PLD can be used to estimate dispersal distance. We propose that a PLD that guarantees a minimum dispersal distance for a wide range of species should be used in the planning of marine protected areas in the deep sea. Based on a review of data on species found at depths >200 m, a PLD of 35 and 69 days ensures a minimum distance for 50 and 75\%, respectively, of eurybathic and deep-sea species. We note that more data are required to enhance accuracy and address the high variability in PLD between and within taxonomic groups, limiting generalizations that are often appealing to decision-makers. Given the imminent expansion of resource exploitation in the deep sea, data relevant to spatial management are needed urgently.",
    url = "https://doi.org/10.3389/fmars.2015.00006",
    doi = "10.3389/fmars.2015.00006",
    openalex = "W2064251247",
    references = "doi103354meps08287"
}

@incollection{harder2018chemical,
    author = "Harder, Tilmann and Tebben, Jan and Möller, Mareen and Schupp, Peter J.",
    title = "Chemical Ecology of Marine Invertebrate Larval Settlement",
    year = "2018",
    booktitle = "Chemical Ecology",
    url = "https://doi.org/10.1201/9780429453465-10",
    doi = "10.1201/9780429453465-10",
    openalex = "W3014717988",
    pages = "329-355",
    references = "doi101016jjembe200910006"
}

How species diversification occurs remains an unanswered question in predatory marine invertebrates, such as sea snails of the family Terebridae. However, the anatomical disparity found throughput the Terebridae provides a unique perspective for investigating diversification patterns in venomous predators. In this study, a new dated molecular phylogeny of the Terebridae is used as a framework for investigating diversification of the family through time, and for testing the putative role of intrinsic and extrinsic traits, such as shell size, larval ecology, bathymetric distribution, and anatomical features of the venom apparatus, as drivers of terebrid species diversification. Macroevolutionary analysis revealed that when diversification rates do not vary across Terebridae clades, the whole family has been increasing its global diversification rate since 25 Ma. We recovered evidence for a concurrent increase in diversification of depth ranges, while shell size appeared to have undergone a fast divergence early in terebrid evolutionary history. Our data also confirm that planktotrophy is the ancestral larval ecology in terebrids, and evolutionary modeling highlighted that shell size is linked to larval ecology of the Terebridae, with species with long-living pelagic larvae tending to be larger and have a broader size range than lecithotrophic species. Although we recovered patterns of size and depth trait diversification through time and across clades, the presence or absence of a venom gland (VG) did not appear to have impacted Terebridae diversification. Terebrids have lost their venom apparatus several times and we confirm that the loss of a VG happened in phylogenetically clustered terminal taxa and that reversal is extremely unlikely. Our findings suggest that environmental factors, and not venom, have had more influence on terebrid evolution.

@article{doi101093sysbiosyz059,
    author = "Modica, Maria Vittoria and Gorson, Juliette and Fedosov, Alexander E and Malcolm, Gavin and Terryn, Yves and Puillandre, Nicolas and Holford, Mandë",
    title = "Macroevolutionary Analyses Suggest That Environmental Factors, Not Venom Apparatus, Play Key Role in Terebridae Marine Snail Diversification.",
    year = "2020",
    journal = "Systematic biology",
    abstract = "How species diversification occurs remains an unanswered question in predatory marine invertebrates, such as sea snails of the family Terebridae. However, the anatomical disparity found throughput the Terebridae provides a unique perspective for investigating diversification patterns in venomous predators. In this study, a new dated molecular phylogeny of the Terebridae is used as a framework for investigating diversification of the family through time, and for testing the putative role of intrinsic and extrinsic traits, such as shell size, larval ecology, bathymetric distribution, and anatomical features of the venom apparatus, as drivers of terebrid species diversification. Macroevolutionary analysis revealed that when diversification rates do not vary across Terebridae clades, the whole family has been increasing its global diversification rate since 25 Ma. We recovered evidence for a concurrent increase in diversification of depth ranges, while shell size appeared to have undergone a fast divergence early in terebrid evolutionary history. Our data also confirm that planktotrophy is the ancestral larval ecology in terebrids, and evolutionary modeling highlighted that shell size is linked to larval ecology of the Terebridae, with species with long-living pelagic larvae tending to be larger and have a broader size range than lecithotrophic species. Although we recovered patterns of size and depth trait diversification through time and across clades, the presence or absence of a venom gland (VG) did not appear to have impacted Terebridae diversification. Terebrids have lost their venom apparatus several times and we confirm that the loss of a VG happened in phylogenetically clustered terminal taxa and that reversal is extremely unlikely. Our findings suggest that environmental factors, and not venom, have had more influence on terebrid evolution.",
    url = "https://pmc.ncbi.nlm.nih.gov/articles/PMC7164365/",
    doi = "10.1093/sysbio/syz059",
    openalex = "W2971453020",
    pmcid = "PMC7164365",
    pmid = "31504987",
    references = "doi101046j14610248200100230x, doi101093bioinformaticsbtl446, doi101093bioinformaticsbtu033, doi101093biomet762297, doi101093molbevmsn083, doi101093nargkh340, doi101111j155856461985tb00420x, doi101186147121487214, doi1014601phytopatholmediterr14998u129, doi1023073802723"
}

ABSTRACT Aim This work addressed the hypotheses that invertebrate species from hydrocarbon seeps at the Pacific Costa Rica Margin (CRM) would descend from adjacent biogeographic provinces, and that common ancestral histories would be identified across invertebrate groups. This research asked: (1) What are the ancestral biogeographic origins of seep species at the CRM and (2) do different invertebrate groups at the CRM show common ancestral origins? The aim of this study was to examine the evolutionary history of this novel and biodiverse region in the deep ocean. Location Costa Rica Margin, Pacific Ocean. Taxa Hydrocarbon Seep Invertebrates (Decapoda, Gastropoda, Bivalvia, Polychaeta). Methods Investigations utilised open‐source sequence data from NCBI GenBank to investigate the ancestral origins of 21 seep species across ten genera and three phyla. Phylogenetic frameworks were used as the foundation for reconstructing ancestral biogeographic ranges of species across time. Results A diversity of ancestral origins for CRM species was found, including the Caribbean Sea, the East Pacific Rise and the Northeast Pacific. Species under investigation originated throughout the Cenozoic, with a peak in diversification in the Pliocene. Almost a quarter of the species (mainly foundational, chemosynthetic taxa) showed evidence of vicariance with the Central American Isthmus, while those remaining (mainly consumers) showed Pacific origins. Connections to the Western Pacific implicate either long‐distance dispersal or unsampled stepping‐stone populations. No obvious patterning between ancestral ranges and mode of larval development was found. Main Conclusions The hypothesis that adjacent biogeographic provinces would give rise to CRM species was partially supported by shared ancestry with the East Pacific Rise and Central Northwest Atlantic, but was not supported by shared ancestries with the Northeast and Western Pacific. The hypothesis that common ancestral histories would be found among invertebrate groups was rejected, as nearly all taxa took a different evolutionary route to colonise the CRM. These results highlight the stochastic nature of speciation in the deep ocean, emphasising the interconnectedness of deep‐sea chemosynthetic ecosystems.

@article{doi101111jbi70199,
    author = "Betters, Melissa and Nocella, Elisa",
    title = "Ancestral Biogeography Reveals Diverse Origins of Costa Rica Margin Seep Invertebrates",
    year = "2026",
    journal = "Journal of Biogeography",
    abstract = "ABSTRACT Aim This work addressed the hypotheses that invertebrate species from hydrocarbon seeps at the Pacific Costa Rica Margin (CRM) would descend from adjacent biogeographic provinces, and that common ancestral histories would be identified across invertebrate groups. This research asked: (1) What are the ancestral biogeographic origins of seep species at the CRM and (2) do different invertebrate groups at the CRM show common ancestral origins? The aim of this study was to examine the evolutionary history of this novel and biodiverse region in the deep ocean. Location Costa Rica Margin, Pacific Ocean. Taxa Hydrocarbon Seep Invertebrates (Decapoda, Gastropoda, Bivalvia, Polychaeta). Methods Investigations utilised open‐source sequence data from NCBI GenBank to investigate the ancestral origins of 21 seep species across ten genera and three phyla. Phylogenetic frameworks were used as the foundation for reconstructing ancestral biogeographic ranges of species across time. Results A diversity of ancestral origins for CRM species was found, including the Caribbean Sea, the East Pacific Rise and the Northeast Pacific. Species under investigation originated throughout the Cenozoic, with a peak in diversification in the Pliocene. Almost a quarter of the species (mainly foundational, chemosynthetic taxa) showed evidence of vicariance with the Central American Isthmus, while those remaining (mainly consumers) showed Pacific origins. Connections to the Western Pacific implicate either long‐distance dispersal or unsampled stepping‐stone populations. No obvious patterning between ancestral ranges and mode of larval development was found. Main Conclusions The hypothesis that adjacent biogeographic provinces would give rise to CRM species was partially supported by shared ancestry with the East Pacific Rise and Central Northwest Atlantic, but was not supported by shared ancestries with the Northeast and Western Pacific. The hypothesis that common ancestral histories would be found among invertebrate groups was rejected, as nearly all taxa took a different evolutionary route to colonise the CRM. These results highlight the stochastic nature of speciation in the deep ocean, emphasising the interconnectedness of deep‐sea chemosynthetic ecosystems.",
    url = "https://doi.org/10.1111/jbi.70199",
    doi = "10.1111/jbi.70199",
    openalex = "W7138877544",
    references = "doi103389fmars20231323156"
}