Dimorphism

@misc{crook1972sexual1,
    author = "Crook, J. H",
    title = "Sexual selection, dimorphism, and social organization in the primates, in Campbell, B. G., ed., Sexual Selection and the Descent of Man (1871-1971)",
    year = "1972",
    howpublished = "Chicago, Aldine-Atherton, p. 231-281",
    note = "talkorigins\_source = {true}; raw\_reference = {Crook, J. H., 1972, Sexual selection, dimorphism, and social organization in the primates, in Campbell, B. G., ed., Sexual Selection and the Descent of Man (1871-1971): Chicago, Aldine-Atherton, p. 231-281.}"
}

@article{chiarelli1974sexual,
    author = "Chiarelli, A. B. and Campbell, Bernard",
    title = "Sexual Selection and the Descent of Man 1871-1971.",
    year = "1974",
    journal = "Man",
    url = "https://doi.org/10.2307/2800047",
    doi = "10.2307/2800047",
    number = "1",
    pages = "143",
    volume = "9"
}

@article{glass1974centennial,
    author = "Glass, Bentley",
    title = "Centennial View of Sexual Selection Sexual Selection and the Descent of Man 1871-1971. Bernard Campbell",
    year = "1974",
    journal = "The Quarterly Review of Biology",
    url = "https://doi.org/10.1086/407903",
    doi = "10.1086/407903",
    number = "1",
    pages = "49-50",
    volume = "49"
}

@article{zihlman1974physical,
    author = "ZIHLMAN, ADRIENNE",
    title = "Physical Anthropology: Sexual Selection and the Descent of Man 1871–1971. BERNARD CAMPBELL, ed",
    year = "1974",
    journal = "American Anthropologist",
    url = "https://doi.org/10.1525/aa.1974.76.2.02a01090",
    doi = "10.1525/aa.1974.76.2.02a01090",
    number = "2",
    pages = "475-478",
    volume = "76"
}

@article{crossref1975sexual,
    title = "Sexual selection and the descent of man. 1871–1971",
    year = "1975",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1016/0047-2484(75)90107-4",
    doi = "10.1016/0047-2484(75)90107-4",
    number = "1",
    pages = "58",
    volume = "4"
}

We have presented a formal model for the quantitative analysis of phylogenetic and specific effects on the distribution of trait values among species. Total trait values are divided into phylogenetic values, inherited from an ancestral species, and specific values, the result of independent evolution. This allows a quantitative assessment of the strength of the phylogenetic inertia, or burden, displayed by a character in a lineage, so that questions concerning the relative importance of phylogenetic constraints in evolution can be answered. The separation of phylogenetic from specific effects proposed here also allows phylogenetic factors to be explicitly included in cross-species comparative analyses of adaptation. This solves a long-standing problem in evolutionary comparative studies. Only species' specific values can provide information concerning the independent evolution of characters in a set of related species. Therefore, only correlations among specific values for traits may be used as evidence for adaptation in cross-species comparative analyses. The phylogenetic autocorrelation model was applied to a comparative analysis of the determinants of sexual dimorphism in weight among 44 primate species. In addition to sexual dimorphism in weight, mating system, habitat, diet, and size (weight itself) were included in the analysis. All of the traits, except diet, were substantially influenced by phylogenetic inertia. The comparative analysis of the determinants of sexual dimorphism in weight indicates that 50% of the variation among primate species is due to phylogeny. Size, or scaling, could account for a total of 36% of the variance, making it almost as important as phylogeny in determining the level of dimorphism displayed by a species. Habitat, mating system, and diet follow, accounting for minor amounts of variation. Thus, in attempting to explain why a particular modern primate species is very dimorphic compared to other primates, we would say first because its ancestor was more dimorphic than average, second because it is a relatively large species, and third because it is terrestrial, polygynous, and folivorous.

@article{doi101111j155856461985tb05699x,
    author = "Cheverud, James M. and Dow, Malcolm M. and Leutenegger, Walter",
    title = "THE QUANTITATIVE ASSESSMENT OF PHYLOGENETIC CONSTRAINTS IN COMPARATIVE ANALYSES: SEXUAL DIMORPHISM IN BODY WEIGHT AMONG PRIMATES",
    year = "1985",
    journal = "Evolution",
    abstract = "We have presented a formal model for the quantitative analysis of phylogenetic and specific effects on the distribution of trait values among species. Total trait values are divided into phylogenetic values, inherited from an ancestral species, and specific values, the result of independent evolution. This allows a quantitative assessment of the strength of the phylogenetic inertia, or burden, displayed by a character in a lineage, so that questions concerning the relative importance of phylogenetic constraints in evolution can be answered. The separation of phylogenetic from specific effects proposed here also allows phylogenetic factors to be explicitly included in cross-species comparative analyses of adaptation. This solves a long-standing problem in evolutionary comparative studies. Only species' specific values can provide information concerning the independent evolution of characters in a set of related species. Therefore, only correlations among specific values for traits may be used as evidence for adaptation in cross-species comparative analyses. The phylogenetic autocorrelation model was applied to a comparative analysis of the determinants of sexual dimorphism in weight among 44 primate species. In addition to sexual dimorphism in weight, mating system, habitat, diet, and size (weight itself) were included in the analysis. All of the traits, except diet, were substantially influenced by phylogenetic inertia. The comparative analysis of the determinants of sexual dimorphism in weight indicates that 50\% of the variation among primate species is due to phylogeny. Size, or scaling, could account for a total of 36\% of the variance, making it almost as important as phylogeny in determining the level of dimorphism displayed by a species. Habitat, mating system, and diet follow, accounting for minor amounts of variation. Thus, in attempting to explain why a particular modern primate species is very dimorphic compared to other primates, we would say first because its ancestor was more dimorphic than average, second because it is a relatively large species, and third because it is terrestrial, polygynous, and folivorous.",
    url = "https://doi.org/10.1111/j.1558-5646.1985.tb05699.x",
    doi = "10.1111/j.1558-5646.1985.tb05699.x",
    openalex = "W2335715110",
    references = "doi101007bf02382954, doi1023072412740"
}

Sexual size dimorphism (SSD) is the evolutionary result of selection operating differently on the body sizes of males and females. Anolis lizard species of the Greater Antilles have been classified into ecomorph classes, largely on the basis of their structural habitat (perch height and diameter). We show that the major ecomorph classes differ in degree of SSD. At least two SSD classes are supported: high SSD (trunk-crown, trunk-ground) and low SSD (trunk, crown-giant, grass-bush, twig). Differences cannot be attributed to an allometric increase of SSD with body size or to a phylogenetic effect. A third explanation, that selective pressures on male and/or female body size vary among habitat types, is examined by evaluating expectations from the major relevant kinds of selective pressures. Although no one kind of selective pressure produces expectations consistent with all of the information, competition with respect to structural habitat and sexual selection pressures are more likely possibilities than competition with respect to prey size or optimal feeding pressures. The existence of habitat-specific sexual dimorphism suggests that adaptation of Anolis species to their environment is more complex than previously appreciated.

@article{doi101111j001438202000tb00026x,
    author = "Butler, Marguerite A. and Schoener, Thomas W. and Losos, Jonathan B.",
    title = "THE RELATIONSHIP BETWEEN SEXUAL SIZE DIMORPHISM AND HABITAT USE IN GREATER ANTILLEAN ANOLIS LIZARDS",
    year = "2000",
    journal = "Evolution",
    abstract = "Sexual size dimorphism (SSD) is the evolutionary result of selection operating differently on the body sizes of males and females. Anolis lizard species of the Greater Antilles have been classified into ecomorph classes, largely on the basis of their structural habitat (perch height and diameter). We show that the major ecomorph classes differ in degree of SSD. At least two SSD classes are supported: high SSD (trunk-crown, trunk-ground) and low SSD (trunk, crown-giant, grass-bush, twig). Differences cannot be attributed to an allometric increase of SSD with body size or to a phylogenetic effect. A third explanation, that selective pressures on male and/or female body size vary among habitat types, is examined by evaluating expectations from the major relevant kinds of selective pressures. Although no one kind of selective pressure produces expectations consistent with all of the information, competition with respect to structural habitat and sexual selection pressures are more likely possibilities than competition with respect to prey size or optimal feeding pressures. The existence of habitat-specific sexual dimorphism suggests that adaptation of Anolis species to their environment is more complex than previously appreciated.",
    url = "https://doi.org/10.1111/j.0014-3820.2000.tb00026.x",
    doi = "10.1111/j.0014-3820.2000.tb00026.x",
    openalex = "W2176419462",
    references = "doi1010029780470316436, doi10108000401706199910485954, doi101086284325, doi101098rstb19890106, doi101111j155856461989tb04220x, doi101537ase188722495, doi1023072409177, doi1043249781315129266, doi105962bhltitle59991, doi105962bhltitle82303"
}

Sexual dimorphism is a pervasive phenomenon among anthropoid primates. Comparative analyses over the past 30 years have greatly expanded our understanding of both variation in the expression of dimorphism among primates, and the underlying causes of sexual dimorphism. Dimorphism in body mass and canine tooth size is familiar, as is pelage and “sex skin” dimorphism. More recent analyses are documenting subtle differences in the pattern of skeletal dimorphism among primates. Comparative analyses have corroborated the sexual selection hypotheses, and have provided a more detailed understanding of the relationship between sexual selection, natural selection, and mating systems in primates. A clearer picture is emerging of the relative contribution of various selective and nonselective mechanisms in the evolution and expression of dimorphism. Most importantly, recent studies have shown that dimorphism is the product of changes in both male and female traits. Developmental studies demonstrate the variety of ontogenetic pathways that can lead to dimorphism, and provide additional insight into the selective mechanisms that influence dimorphism throughout the lifetime of an animal. Evidence from the fossil record suggests that dimorphism probably evolved in parallel twice, and the dimorphism in some extinct hominoids probably exceeded that of any living primate. Our advances in understanding the behavioral/ecological correlates of dimorphism in living primates have not improved our ability to reconstruct social systems in extinct species on the basis of dimorphism alone, beyond the inference of polygyny or intense male-male competition. However, our understanding of the behavioral/ecological correlates of growth and development, and of the expression of dimorphism as a function of separate changes in male and female traits, offers great potential for inferring evolutionary changes in behavior over time. Yrbk Phys Anthropol 44:25–53, 2001. © 2001 Wiley-Liss, Inc.

@article{doi101002ajpa10011,
    author = "Plavcan, J. Michael",
    title = "Sexual dimorphism in primate evolution",
    year = "2001",
    journal = "American Journal of Physical Anthropology",
    abstract = "Sexual dimorphism is a pervasive phenomenon among anthropoid primates. Comparative analyses over the past 30 years have greatly expanded our understanding of both variation in the expression of dimorphism among primates, and the underlying causes of sexual dimorphism. Dimorphism in body mass and canine tooth size is familiar, as is pelage and “sex skin” dimorphism. More recent analyses are documenting subtle differences in the pattern of skeletal dimorphism among primates. Comparative analyses have corroborated the sexual selection hypotheses, and have provided a more detailed understanding of the relationship between sexual selection, natural selection, and mating systems in primates. A clearer picture is emerging of the relative contribution of various selective and nonselective mechanisms in the evolution and expression of dimorphism. Most importantly, recent studies have shown that dimorphism is the product of changes in both male and female traits. Developmental studies demonstrate the variety of ontogenetic pathways that can lead to dimorphism, and provide additional insight into the selective mechanisms that influence dimorphism throughout the lifetime of an animal. Evidence from the fossil record suggests that dimorphism probably evolved in parallel twice, and the dimorphism in some extinct hominoids probably exceeded that of any living primate. Our advances in understanding the behavioral/ecological correlates of dimorphism in living primates have not improved our ability to reconstruct social systems in extinct species on the basis of dimorphism alone, beyond the inference of polygyny or intense male-male competition. However, our understanding of the behavioral/ecological correlates of growth and development, and of the expression of dimorphism as a function of separate changes in male and female traits, offers great potential for inferring evolutionary changes in behavior over time. Yrbk Phys Anthropol 44:25–53, 2001. © 2001 Wiley-Liss, Inc.",
    url = "https://doi.org/10.1002/ajpa.10011",
    doi = "10.1002/ajpa.10011",
    openalex = "W4211119249",
    references = "doi101002ajpa1330600302, doi101006jhev19960122, doi101007bf02382954, doi10103712293000, doi101111j155856461980tb04817x, doi101126science2114480341, doi101126science327542, doi101146annurevecolsys281659, doi1015159780691207278, doi1043249781315129266, doi105962bhltitle27468, doi107312rens91062"
}

Sexual dimorphism is a pervasive phenomenon among anthropoid primates. Comparative analyses over the past 30 years have greatly expanded our understanding of both variation in the expression of dimorphism among primates, and the underlying causes of sexual dimorphism. Dimorphism in body mass and canine tooth size is familiar, as is pelage and "sex skin" dimorphism. More recent analyses are documenting subtle differences in the pattern of skeletal dimorphism among primates. Comparative analyses have corroborated the sexual selection hypotheses, and have provided a more detailed understanding of the relationship between sexual selection, natural selection, and mating systems in primates. A clearer picture is emerging of the relative contribution of various selective and nonselective mechanisms in the evolution and expression of dimorphism. Most importantly, recent studies have shown that dimorphism is the product of changes in both male and female traits. Developmental studies demonstrate the variety of ontogenetic pathways that can lead to dimorphism, and provide additional insight into the selective mechanisms that influence dimorphism throughout the lifetime of an animal. Evidence from the fossil record suggests that dimorphism probably evolved in parallel twice, and the dimorphism in some extinct hominoids probably exceeded that of any living primate. Our advances in understanding the behavioral/ecological correlates of dimorphism in living primates have not improved our ability to reconstruct social systems in extinct species on the basis of dimorphism alone, beyond the inference of polygyny or intense male-male competition. However, our understanding of the behavioral/ecological correlates of growth and development, and of the expression of dimorphism as a function of separate changes in male and female traits, offers great potential for inferring evolutionary changes in behavior over time.

@article{doi101002ajpa10011abs,
    author = "Plavcan, J. Michael",
    title = "Sexual dimorphism in primate evolution",
    year = "2001",
    journal = "American Journal of Physical Anthropology",
    abstract = {Sexual dimorphism is a pervasive phenomenon among anthropoid primates. Comparative analyses over the past 30 years have greatly expanded our understanding of both variation in the expression of dimorphism among primates, and the underlying causes of sexual dimorphism. Dimorphism in body mass and canine tooth size is familiar, as is pelage and "sex skin" dimorphism. More recent analyses are documenting subtle differences in the pattern of skeletal dimorphism among primates. Comparative analyses have corroborated the sexual selection hypotheses, and have provided a more detailed understanding of the relationship between sexual selection, natural selection, and mating systems in primates. A clearer picture is emerging of the relative contribution of various selective and nonselective mechanisms in the evolution and expression of dimorphism. Most importantly, recent studies have shown that dimorphism is the product of changes in both male and female traits. Developmental studies demonstrate the variety of ontogenetic pathways that can lead to dimorphism, and provide additional insight into the selective mechanisms that influence dimorphism throughout the lifetime of an animal. Evidence from the fossil record suggests that dimorphism probably evolved in parallel twice, and the dimorphism in some extinct hominoids probably exceeded that of any living primate. Our advances in understanding the behavioral/ecological correlates of dimorphism in living primates have not improved our ability to reconstruct social systems in extinct species on the basis of dimorphism alone, beyond the inference of polygyny or intense male-male competition. However, our understanding of the behavioral/ecological correlates of growth and development, and of the expression of dimorphism as a function of separate changes in male and female traits, offers great potential for inferring evolutionary changes in behavior over time.},
    url = "https://doi.org/10.1002/ajpa.10011.abs",
    doi = "10.1002/ajpa.10011.abs",
    openalex = "W2122501476",
    references = "crossref2017sexual, doi101006jhev19960122, doi10103712293000, doi101111j155856461980tb04817x, doi101126science2114480341, doi101126science327542, doi101537ase188722495, doi1023072341823, doi10432497813151292667, doi105860choice263889, doi105962bhltitle27468"
}

@incollection{plavcan2005seasonality,
    author = "Plavcan, J. Michael and van Schaik, Carel P. and McGraw, W. Scott",
    title = "Seasonality, social organization, and sexual dimorphism in primates",
    year = "2005",
    booktitle = "Seasonality in Primates",
    url = "https://doi.org/10.1017/cbo9780511542343.015",
    doi = "10.1017/cbo9780511542343.015",
    openalex = "W155478282",
    pages = "401-442",
    references = "doi101006jhev19960122, doi101016s0065345413600017, doi101093sysbio423265, doi101098rspb19890027, doi101111j155856461980tb04817x, doi101111j155856461986tb00560x, doi101126science327542, doi1015159780691207278, doi1015159781400858149, openalexw2097385721"
}

Researchers have described multilevel societies with one-male, multifemale units (OMUs) forming within a larger group in several catarrhine species, but not in platyrhines. OMUs in multilevel societies are associated with extremely large group sizes, often with >100 individuals, and the only platyrhine genus that forms groups of this size is Cacajao. We review available evidence for multilevel organization and the formation of OMUs in groups of Cacajao, and test predictions for the frequency distribution patterns of male-male and male-female interindividual distances within groups of red-faced uakaris (Cacajao calvus ucayalii), comparing year-round data with those collected at the peak of the breeding season, when group cohesion may be more pronounced. Groups of Cacajao fission and fuse, forming subgroup sizes at frequencies consistent with an OMU organization. In Cacajao calvus ucayalii and Cacajao calvus calvus, bachelor groups are also observed, a characteristic of several catarrhine species that form OMUs. However, researchers have observed both multimale-multifemale groups and groups with a single male and multiple females in Cacajao calvus. The frequency distributions of interindividual distances for male-male and male-female dyads are consistent with an OMU-based organization, but alternative interpretations of these data are possible. The distribution of interindividual distances collected during the peak breeding season differed from those collected year-round, indicating seasonal changes in the spatial organization of Cacajao calvus ucayalii. We suggest a high degree of flexibility may characterize the social organization of Cacajao calvus ucayalii, which may form OMUs under certain conditions. Further studies with identifiable individuals, thus far not possible in Cacajao, are required to confirm the social organization.

@article{doi101007s1076401296036,
    author = "Bowler, Mark and Knogge, Christoph and Heymann, Eckhard W. and Zinner, Dietmar",
    title = "Multilevel Societies in New World Primates? Flexibility May Characterize the Organization of Peruvian Red Uakaris (Cacajao calvus ucayalii)",
    year = "2012",
    journal = "International Journal of Primatology",
    abstract = "Researchers have described multilevel societies with one-male, multifemale units (OMUs) forming within a larger group in several catarrhine species, but not in platyrhines. OMUs in multilevel societies are associated with extremely large group sizes, often with >100 individuals, and the only platyrhine genus that forms groups of this size is Cacajao. We review available evidence for multilevel organization and the formation of OMUs in groups of Cacajao, and test predictions for the frequency distribution patterns of male-male and male-female interindividual distances within groups of red-faced uakaris (Cacajao calvus ucayalii), comparing year-round data with those collected at the peak of the breeding season, when group cohesion may be more pronounced. Groups of Cacajao fission and fuse, forming subgroup sizes at frequencies consistent with an OMU organization. In Cacajao calvus ucayalii and Cacajao calvus calvus, bachelor groups are also observed, a characteristic of several catarrhine species that form OMUs. However, researchers have observed both multimale-multifemale groups and groups with a single male and multiple females in Cacajao calvus. The frequency distributions of interindividual distances for male-male and male-female dyads are consistent with an OMU-based organization, but alternative interpretations of these data are possible. The distribution of interindividual distances collected during the peak breeding season differed from those collected year-round, indicating seasonal changes in the spatial organization of Cacajao calvus ucayalii. We suggest a high degree of flexibility may characterize the social organization of Cacajao calvus ucayalii, which may form OMUs under certain conditions. Further studies with identifiable individuals, thus far not possible in Cacajao, are required to confirm the social organization.",
    url = "https://doi.org/10.1007/s10764-012-9603-6",
    doi = "10.1007/s10764-012-9603-6",
    openalex = "W2110259272",
    references = "doi101007bf02373629"
}

@incollection{crossref2017sexual,
    title = "Sexual Selection, Dimorphism, and Social Organization in the Primates",
    year = "2017",
    booktitle = "Sexual Selection and the Descent of Man",
    url = "https://doi.org/10.4324/9781315129266-9",
    doi = "10.4324/9781315129266-9",
    pages = "231-281"
}