Homonoids

@article{doi101038202005a0,
    author = "Leakey, L. S. B. and Leakey, Mary D.",
    title = "Recent Discoveries of Fossil Hominids in Tanganyika: At Olduvai and Near Lake Natron",
    year = "1964",
    journal = "Nature",
    url = "https://doi.org/10.1038/202005a0",
    doi = "10.1038/202005a0",
    openalex = "W2018237921"
}

@article{doi1023072401323,
    author = "Laws, R. M. and Howell, F. Clark and Bourlière, F",
    title = "African Ecology and Human Evolution.",
    year = "1964",
    journal = "Journal of Applied Ecology",
    url = "https://doi.org/10.2307/2401323",
    doi = "10.2307/2401323",
    openalex = "W2325221466"
}

Several workers have observed that there is an extremely close immunological resemblance between the serum albumins of apes and man. Our studies with the quantitative micro-complement fixation method confirm this observation. To explain the closeness of the resemblance, previous workers suggested that there has been a slowing down of albumin evolution since the time of divergence of apes and man. Recent evidence, however, indicates that the albumin molecule has evolved at a steady rate. Hence, we suggest that apes and man have a more recent common ancestry than is usually supposed. Our calculations lead to the suggestion that, if man and Old World monkeys last shared a common ancestor 30 million years ago, then man and African apes shared a common ancestor 5 million years ago, that is, in the Pliocene era.

@article{doi101126science15838051200,
    author = "Sarich, Vincent M. and Wilson, Allan C.",
    title = "Immunological Time Scale for Hominid Evolution",
    year = "1967",
    journal = "Science",
    abstract = "Several workers have observed that there is an extremely close immunological resemblance between the serum albumins of apes and man. Our studies with the quantitative micro-complement fixation method confirm this observation. To explain the closeness of the resemblance, previous workers suggested that there has been a slowing down of albumin evolution since the time of divergence of apes and man. Recent evidence, however, indicates that the albumin molecule has evolved at a steady rate. Hence, we suggest that apes and man have a more recent common ancestry than is usually supposed. Our calculations lead to the suggestion that, if man and Old World monkeys last shared a common ancestor 30 million years ago, then man and African apes shared a common ancestor 5 million years ago, that is, in the Pliocene era.",
    url = "https://doi.org/10.1126/science.158.3805.1200",
    doi = "10.1126/science.158.3805.1200",
    openalex = "W2048918147",
    references = "doi101002ajpa1330260211, doi1010160002934366901458, doi101016s006532330860128x, doi101038202147a0, doi101038205135a0, doi101038213155a0, doi101073pnas581142, doi101126science147365368, doi101159000155026, doi1043249781315081083"
}

@article{doi1023072798879,
    author = "Day, M. H. and Wood, Bernard",
    title = "Functional Affinities of the Olduvai Hominid 8 Talus",
    year = "1968",
    journal = "Man",
    url = "https://doi.org/10.2307/2798879",
    doi = "10.2307/2798879",
    openalex = "W2800728273"
}

@article{doi1023072798801,
    author = "Jolly, Clifford J.",
    title = "The Seed-Eaters: A New Model of Hominid Differentiation Based on a Baboon Analogy",
    year = "1970",
    journal = "Man",
    url = "https://doi.org/10.2307/2798801",
    doi = "10.2307/2798801",
    openalex = "W4254547492"
}

@article{doi101038231241a0,
    author = "Leakey, Richard E.",
    title = "Further Evidence of Lower Pleistocene Hominids from East Rudolf, North Kenya",
    year = "1971",
    journal = "Nature",
    url = "https://doi.org/10.1038/231241a0",
    doi = "10.1038/231241a0",
    openalex = "W4246402040"
}

@article{doi1023072799185,
    author = "Wolpoff, Milford H.",
    title = "Competitive Exclusion Among Lower Pleistocene Hominids: The Single Species Hypothesis",
    year = "1971",
    journal = "Man",
    url = "https://doi.org/10.2307/2799185",
    doi = "10.2307/2799185",
    openalex = "W2798247443"
}

Q vi of fissuration."I was aware, too, of the considerable subjective element that has often entered into such studies, especially when applied to interracial comparisons; of the fact that it is most difficult, and for some characters virtually impossible, to express such observations in precise metrical form; and of the comment by the distinguished neuroanatomist, Dr. Gerhardt von Bonin, after a lifetime of studies on brains and endocasts: "It should at last be admitted that most of what has been said and written on the sulci of the brain as they have been seen on endocasts is worth very little" (von Bonin 1963, p. 50), a view that is shared by not a few of those mentioned above.These are among the reasons why I have chosen to confine this study to brain size and endocranial capacity.It started, as I have said, as a single lecture and, as such, possesses a single unifying theme.Briefly stated, it is this: nothing is more striking and more sustained in the whole of human evolution than the twofold trend towards increase in brain size on the one hand, and, on the other, towards cultural activities, cultural mastery, and, indeed, utter dependence on culture for survival.These two sets of changes are indissolubly linked.The chain between them may be set forth simply as follows: increase in brain size = gain in intricacy of neuronal organization = rise in complexity of nervous function = ever more diversified and complicated behavior responses = progressively amplified and enhanced cultural manifestations.This essay explores the first and last steps of this causal chain-the steps that are directly manifest in the fossil record.It pleads that these two items are valid fields of study, each in its own right, irrespective of the tangled skein that may connect them.With Stephan (1969), this essay accepts that 'The functional capacity of a system depends upon its size and structural differentiation" (italics mine); that, in addition, '""The two variables of structure-size and differentiation-in general do not vary independently," but that "... the differentiation can vary in many ways (e.g. in construction, arrangements and connection of the cells, units, layers, etc.), whereas for variations in size there are only two possibilities: enlargement or reduction" (Stephan 1969, p. 34).This work fully recognizes the importance of the intervening areas of knowledge.In fact, it very gingerly peers into the murky fastnesses of the fossil neuron, the glia-'neuron ratio and relationship, the feedback chains, and other components of the middle links that will one day establish the logic and the causality uniting the termini.Into this no-man's land, at present, only the intrepid few are venturing.It is in these QG x intervening areas that the next major chapter in the history of the brain in hominid evolution waits to be written.Meantime, this little book attempts to marshal and evaluate the crucial evidence at the two ends of the chain: for accurate observation and cautious interpretation of these relatively simple and modest first criteria are the foundations upon which any later, profounder study must be predicated.

@book{doi105962bhltitle15880,
    author = "Tobias, Phillip V.",
    title = "The brain in hominid evolution",
    year = "1971",
    booktitle = "Columbia University Press eBooks",
    abstract = {Q vi of fissuration."I was aware, too, of the considerable subjective element that has often entered into such studies, especially when applied to interracial comparisons; of the fact that it is most difficult, and for some characters virtually impossible, to express such observations in precise metrical form; and of the comment by the distinguished neuroanatomist, Dr. Gerhardt von Bonin, after a lifetime of studies on brains and endocasts: "It should at last be admitted that most of what has been said and written on the sulci of the brain as they have been seen on endocasts is worth very little" (von Bonin 1963, p. 50), a view that is shared by not a few of those mentioned above.These are among the reasons why I have chosen to confine this study to brain size and endocranial capacity.It started, as I have said, as a single lecture and, as such, possesses a single unifying theme.Briefly stated, it is this: nothing is more striking and more sustained in the whole of human evolution than the twofold trend towards increase in brain size on the one hand, and, on the other, towards cultural activities, cultural mastery, and, indeed, utter dependence on culture for survival.These two sets of changes are indissolubly linked.The chain between them may be set forth simply as follows: increase in brain size = gain in intricacy of neuronal organization = rise in complexity of nervous function = ever more diversified and complicated behavior responses = progressively amplified and enhanced cultural manifestations.This essay explores the first and last steps of this causal chain-the steps that are directly manifest in the fossil record.It pleads that these two items are valid fields of study, each in its own right, irrespective of the tangled skein that may connect them.With Stephan (1969), this essay accepts that 'The functional capacity of a system depends upon its size and structural differentiation" (italics mine); that, in addition, '""The two variables of structure-size and differentiation-in general do not vary independently," but that "... the differentiation can vary in many ways (e.g. in construction, arrangements and connection of the cells, units, layers, etc.), whereas for variations in size there are only two possibilities: enlargement or reduction" (Stephan 1969, p. 34).This work fully recognizes the importance of the intervening areas of knowledge.In fact, it very gingerly peers into the murky fastnesses of the fossil neuron, the glia-'neuron ratio and relationship, the feedback chains, and other components of the middle links that will one day establish the logic and the causality uniting the termini.Into this no-man's land, at present, only the intrepid few are venturing.It is in these QG x intervening areas that the next major chapter in the history of the brain in hominid evolution waits to be written.Meantime, this little book attempts to marshal and evaluate the crucial evidence at the two ends of the chain: for accurate observation and cautious interpretation of these relatively simple and modest first criteria are the foundations upon which any later, profounder study must be predicated.},
    url = "https://doi.org/10.5962/bhl.title.15880",
    doi = "10.5962/bhl.title.15880",
    openalex = "W2476847938",
    references = "doi101002ajpa1330020102, doi101002jmor1051240204, doi101038115195a0, doi101038184491a0, doi1010382011264a0, doi101038202007a0, doi101111j146979981960tb05606x, doi101126science14035711081, doi1023073101360, eiseley1955fossil, greene1963mankind, openalexw2150985179"
}

@article{doi101038237264a0,
    author = "Leakey, Richard E.",
    title = "Further Evidence of Lower Pleistocene Hominids from East Rudolf, North Kenya, 1971",
    year = "1972",
    journal = "Nature",
    url = "https://doi.org/10.1038/237264a0",
    doi = "10.1038/237264a0",
    openalex = "W4251580063"
}

@article{doi101038242170a0,
    author = "Leakey, Richard E.",
    title = "Further Evidence of Lower Pleistocene Hominids from East Rudolf, North Kenya, 1972",
    year = "1973",
    journal = "Nature",
    url = "https://doi.org/10.1038/242170a0",
    doi = "10.1038/242170a0",
    openalex = "W4229849167"
}

@article{doi101038242447a0,
    author = "Leakey, Richard E.",
    title = "Evidence for an Advanced Plio-Pleistocene Hominid from East Rudolf, Kenya",
    year = "1973",
    journal = "Nature",
    url = "https://doi.org/10.1038/242447a0",
    doi = "10.1038/242447a0",
    openalex = "W1997760482",
    references = "doi101002ajpa1330360212, doi101038226223a0, doi101038231241a0, doi101038237264a0, doi101038239379a0, doi101038242170a0, doi101038242391a0, doi101126science1683934966, doi105962bhltitle15880"
}

@article{doi101038248653a0,
    author = "Leakey, Richard E.",
    title = "Further evidence of Lower Pleistocene hominids from East Rudolf, North Kenya, 1973",
    year = "1974",
    journal = "Nature",
    url = "https://doi.org/10.1038/248653a0",
    doi = "10.1038/248653a0",
    openalex = "W1994411951",
    references = "doi101002ajpa1330360212, doi101017cbo9780511897795, doi101038189649a0, doi101038202005a0, doi1010382231234a0, doi101038226918a0, doi101038231241a0, doi101038242170a0, doi101038242447a0, doi1023072798879"
}

@article{doi101038260289a0,
    author = "Taieb, Maurice and Johanson, Donald C. and Coppens, Yves and Aronson, James L.",
    title = "Geological and palaeontological background of Hadar hominid site, Afar, Ethiopia",
    year = "1976",
    journal = "Nature",
    url = "https://doi.org/10.1038/260289a0",
    doi = "10.1038/260289a0",
    openalex = "W1985132650"
}

@article{doi101038260293a0,
    author = "Johanson, Donald C. and Taieb, Maurice",
    title = "Plio—Pleistocene hominid discoveries in Hadar, Ethiopia",
    year = "1976",
    journal = "Nature",
    url = "https://doi.org/10.1038/260293a0",
    doi = "10.1038/260293a0",
    openalex = "W1992693329",
    references = "doi101002ajpa1330070105, doi101002ajpa1330350109, doi101038202007a0, doi101038221230a0, doi101038242170a0, doi101038248653a0, doi101038260289a0"
}

@article{doi101016s0047248477800511,
    author = "Delson, Eric and Eldredge, Niles and Tattersall, Ian",
    title = "Reconstruction of hominid phylogeny: A testable framework based on cladistic analysis",
    year = "1977",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1016/s0047-2484(77)80051-1",
    doi = "10.1016/s0047-2484(77)80051-1",
    openalex = "W2049102891"
}

@article{wood1977african,
    author = "Wood, Bernard",
    title = "African fossil hominids",
    year = "1977",
    journal = "Nature",
    url = "https://doi.org/10.1038/270766a0",
    doi = "10.1038/270766a0",
    number = "5639",
    openalex = "W2047229267",
    pages = "766-766",
    volume = "270"
}

A large sample of Pliocene fossil hominid remains has been recovered from the African sites of Hadar in Ethiopia and Laetolil in Tanzania. These collections, dating approximately between 2.9 and 3.8 million years ago, constitute the earliest substantial record of the family Hominidae. This article assesses the phylogenetic relationships of the newly discovered fossil hominids and provides a taxonomy consistent with that assessment. A new taxon, Australopithecus afarensis, has been created to accommodate these Pliocene hominid fossils.

@article{johanson1979a,
    author = "Johanson, D. C. and White, T. D.",
    title = "A Systematic Assessment of Early African Hominids",
    year = "1979",
    journal = "Science",
    abstract = "A large sample of Pliocene fossil hominid remains has been recovered from the African sites of Hadar in Ethiopia and Laetolil in Tanzania. These collections, dating approximately between 2.9 and 3.8 million years ago, constitute the earliest substantial record of the family Hominidae. This article assesses the phylogenetic relationships of the newly discovered fossil hominids and provides a taxonomy consistent with that assessment. A new taxon, Australopithecus afarensis, has been created to accommodate these Pliocene hominid fossils.",
    url = "https://doi.org/10.1126/science.104384",
    doi = "10.1126/science.104384",
    number = "4378",
    openalex = "W2027226179",
    pages = "321-330",
    volume = "203",
    references = "doi101002ajpa1330080109, doi101017cbo9780511897795, doi101038115195a0, doi101038142377a0, doi101038184491a0, doi101038202007a0, doi101038248653a0, doi101038254301a0, doi101038260293a0, doi101086397067, doi101126science15838051200"
}

@misc{johanson1979a1,
    author = "Johanson, D. C. and White, T. D",
    title = "A Systematic Assessment of Early African Hominids",
    year = "1979",
    howpublished = "Science, v. 203, p. 320-330",
    note = "talkorigins\_source = {true}; raw\_reference = {Johanson, D. C., and White, T. D., 1979, A Systematic Assessment of Early African Hominids: Science, v. 203, p. 320-330.}"
}

In modern man the pitch of the occlusal plane may vary along the tooth-row. When anterior cheek-teeth show a plane sloping upward palatally, whilst that on posterior cheek-teeth slopes upward buccally, there results a twisted or helicoidal occlusal plane (Ackermann). Several hypotheses have been proposed for the structural basis of the helicoidal occlusal plane. Campbell's proposal ('25) has gained widest acceptance, namely that the helicoid results from anteroposterior differences in upper and lower alveolar arch width. In the early 1960s, while studying the Olduvai hominids assigned to Homo habilis, the author noted changing occlusal slopes along the tooth-row and a slight helicoid, although these featues had not been noted in other early hominids. Subsequently, Wallace showed a total absence of the helicoid from South African australopithecines, and its presence in Swartkrans Homo, SK 45 and SK 80. Recent studies confirm the presence of the helicoid in all available specimens of H. habilis, including Stw 53 found at Sterkfontein in 1976. Hence, this trait may distinguish between Australopithecus and early Homo. Measurements of the maxillary arch widths have shown that, whereas in Australopithecus arch widths increase to a maximum at M3, in early Homo maxillary arch widths are greatest at M2. The decline in posterior maxillary arch width is part of a general reduction of that region. Thus despite striking elongation of premolars and M1 in early Homo, M2 and M3 are mesiodistally abbreviated. It is hypothesized that the onset of posterior arch reduction, with the appearance of a helicoid, was a structural and functional concomitant of the transition from the presumed australopithecine ancestor to H. habilis.

@article{doi101002ajpa1330530202,
    author = "Tobias, Phillip V.",
    title = "The natural history of the helicoidal occlusal plane and its evolution in early Homo",
    year = "1980",
    journal = "American Journal of Physical Anthropology",
    abstract = "In modern man the pitch of the occlusal plane may vary along the tooth-row. When anterior cheek-teeth show a plane sloping upward palatally, whilst that on posterior cheek-teeth slopes upward buccally, there results a twisted or helicoidal occlusal plane (Ackermann). Several hypotheses have been proposed for the structural basis of the helicoidal occlusal plane. Campbell's proposal ('25) has gained widest acceptance, namely that the helicoid results from anteroposterior differences in upper and lower alveolar arch width. In the early 1960s, while studying the Olduvai hominids assigned to Homo habilis, the author noted changing occlusal slopes along the tooth-row and a slight helicoid, although these featues had not been noted in other early hominids. Subsequently, Wallace showed a total absence of the helicoid from South African australopithecines, and its presence in Swartkrans Homo, SK 45 and SK 80. Recent studies confirm the presence of the helicoid in all available specimens of H. habilis, including Stw 53 found at Sterkfontein in 1976. Hence, this trait may distinguish between Australopithecus and early Homo. Measurements of the maxillary arch widths have shown that, whereas in Australopithecus arch widths increase to a maximum at M3, in early Homo maxillary arch widths are greatest at M2. The decline in posterior maxillary arch width is part of a general reduction of that region. Thus despite striking elongation of premolars and M1 in early Homo, M2 and M3 are mesiodistally abbreviated. It is hypothesized that the onset of posterior arch reduction, with the appearance of a helicoid, was a structural and functional concomitant of the transition from the presumed australopithecine ancestor to H. habilis.",
    url = "https://doi.org/10.1002/ajpa.1330530202",
    doi = "10.1002/ajpa.1330530202",
    openalex = "W2025447683"
}

The O.H. 7 brain endocast was reexamined using a stereoplotting apparatus to quantify the amount of distortion. Some 127 measurements for each of the left and right sides were taken and treated statically by student t-tests, both in paired and grouped fashion. Grouped data indicated no significant left-right differences. Paired data suggested three small regions of distortion, which produced three pairs of left-right differences that were significantly different. Given the very local nature of these minor distortions, it is concluded that the original reconstruction by Tobias was essentially correct. In addition, multiple regression analyses of selected chord-arc dimensions suggest that a volume in excess of 700 ml is most probable.

@article{doi101002ajpa1330530211,
    author = "Holloway, Ralph L.",
    title = "The O.H. 7 (Olduvai Gorge, Tanzania) hominid partial brain endocast revisited",
    year = "1980",
    journal = "American Journal of Physical Anthropology",
    abstract = "The O.H. 7 brain endocast was reexamined using a stereoplotting apparatus to quantify the amount of distortion. Some 127 measurements for each of the left and right sides were taken and treated statically by student t-tests, both in paired and grouped fashion. Grouped data indicated no significant left-right differences. Paired data suggested three small regions of distortion, which produced three pairs of left-right differences that were significantly different. Given the very local nature of these minor distortions, it is concluded that the original reconstruction by Tobias was essentially correct. In addition, multiple regression analyses of selected chord-arc dimensions suggest that a volume in excess of 700 ml is most probable.",
    url = "https://doi.org/10.1002/ajpa.1330530211",
    doi = "10.1002/ajpa.1330530211",
    openalex = "W1999866812"
}

Sulcal patterns of six previously available South African australopithecine natural endocasts are reexamined and compared to sulcal patterns of 17 human, 12 gorilla and six chimpanzee brains. In addition, a seventh natural endocast, from STS 58, is described for the first time and compared to an artificial endocast from the same specimen. Using the Taung endocast as a focal point, it is shown that sulcal patterns reproduced on natural endocasts of australopithecines appear to be pongid-like rather than human-like. Contrary to earlier descriptions, the lunate sulcus occupies a rostral position similar to that found in pongids. Since South African australopithecine brains do not appear to be reorganized along human lines at a gross external neuroanatomical level, the concept of neurological reorganization is best applied at finer neurological levels, perhaps at the level of the neuron or at a neurochemical level. Thus, future studies by comparative neuroscientists are more likely to elucidate the fine details of neurological reorganization that occurred during early human evolution than are studies by paleontologists who directly observe the australopithecine fossil record of natural endocasts.

@article{doi101002ajpa1330530409,
    author = "Falk, Dean",
    title = "A reanalysis of the South African australopithecine natural endocasts",
    year = "1980",
    journal = "American Journal of Physical Anthropology",
    abstract = "Sulcal patterns of six previously available South African australopithecine natural endocasts are reexamined and compared to sulcal patterns of 17 human, 12 gorilla and six chimpanzee brains. In addition, a seventh natural endocast, from STS 58, is described for the first time and compared to an artificial endocast from the same specimen. Using the Taung endocast as a focal point, it is shown that sulcal patterns reproduced on natural endocasts of australopithecines appear to be pongid-like rather than human-like. Contrary to earlier descriptions, the lunate sulcus occupies a rostral position similar to that found in pongids. Since South African australopithecine brains do not appear to be reorganized along human lines at a gross external neuroanatomical level, the concept of neurological reorganization is best applied at finer neurological levels, perhaps at the level of the neuron or at a neurochemical level. Thus, future studies by comparative neuroscientists are more likely to elucidate the fine details of neurological reorganization that occurred during early human evolution than are studies by paleontologists who directly observe the australopithecine fossil record of natural endocasts.",
    url = "https://doi.org/10.1002/ajpa.1330530409",
    doi = "10.1002/ajpa.1330530409",
    openalex = "W2143417155",
    references = "doi101126science1683934966, holloway1974the"
}

A previous article outlined the new fossil evidence on man's origins recovered from East Africa and Ethiopia. Two problems raised by these fossil finds are discussed here.The first concerns the evolutionary relationship obtaining between Australopithecus and Homo. The claimed coexistence between australopithecines and early forms of the genus Homo has sometimes been regarded as proof that the former could no longer be regarded as ancestral to the latter. More recent finds in Laetolil and Hadar, however, suggest that an early australopithecine form may have been ancestral to both later australopithecines and early species of Homo. This interpretation is compatible both with the traditional view that sees Australopithecus as ancestral to Homo and with the claimed coexistence of australopithecines with more advanced hominids.The second problem here considered has to do with the coexistence at a number of sites in East Africa, for longer periods of time, of several distinct hominid lineages. Such coexistence is best documented in Omo, East Turkana and Olduvai. The most parsimonious interpretation of the fossil finds recognizes the coexistence of two distinct hominid lineages, one fairly uniform and perduring unchanged for over 1 million years (the robust australopithecines), the other comprising a variety of more gracile hominids. The large range of variation of the latter lineage creates as yet unsolved problems for the taxonomist, but it is apparently out of this variety of more gracile hominids that emerged Homo erectus whose appearance seems to have been the principal factor that occasioned the extinction of the robust australopithecine lineage.

@article{doi101537ase191188201,
    author = "Kitahara-Frisch, J.",
    title = "Recent Hominid Finds in East Africa and Ethiopia",
    year = "1980",
    journal = "The Journal of Anthropological Society of Nippon",
    abstract = "A previous article outlined the new fossil evidence on man's origins recovered from East Africa and Ethiopia. Two problems raised by these fossil finds are discussed here.The first concerns the evolutionary relationship obtaining between Australopithecus and Homo. The claimed coexistence between australopithecines and early forms of the genus Homo has sometimes been regarded as proof that the former could no longer be regarded as ancestral to the latter. More recent finds in Laetolil and Hadar, however, suggest that an early australopithecine form may have been ancestral to both later australopithecines and early species of Homo. This interpretation is compatible both with the traditional view that sees Australopithecus as ancestral to Homo and with the claimed coexistence of australopithecines with more advanced hominids.The second problem here considered has to do with the coexistence at a number of sites in East Africa, for longer periods of time, of several distinct hominid lineages. Such coexistence is best documented in Omo, East Turkana and Olduvai. The most parsimonious interpretation of the fossil finds recognizes the coexistence of two distinct hominid lineages, one fairly uniform and perduring unchanged for over 1 million years (the robust australopithecines), the other comprising a variety of more gracile hominids. The large range of variation of the latter lineage creates as yet unsolved problems for the taxonomist, but it is apparently out of this variety of more gracile hominids that emerged Homo erectus whose appearance seems to have been the principal factor that occasioned the extinction of the robust australopithecine lineage.",
    url = "https://doi.org/10.1537/ase1911.88.201",
    doi = "10.1537/ase1911.88.201",
    openalex = "W4256628679",
    references = "doi101038202007a0, doi101038237264a0, doi101038260293a0, doi104159harvard9780674431263, doi104159harvard9780674592971c14, johanson2017a"
}

Abstract The large collections of fossil hominid remains from Hadar, Ethiopia, derive from the Afar Triangle of the continental East African Rift. The fossils constitute much of the paratype series of Australopithecus afarensis (Johanson, White, and Coppens, 1978*). Citations for starred (*) references appear in Appendix 2, Publications. The primitive morphology exhibited by these hominids is consistent with their chronologic placement between 3.0 and 4.0 m.y. This paper provides the geographic, historic, stratigraphic, paleoenvironmental, and systematic background for Hadar fossil hominids described in this volume.

@article{doi101002ajpa1330570402,
    author = "Johanson, Donald C. and Taieb, Maurice and Coppens, Yves",
    title = "Pliocene hominids from the Hadar formation, Ethiopia (1973–1977): Stratigraphic, chronologic, and paleoenvironmental contexts, with notes on hominid morphology and systematics",
    year = "1982",
    journal = "American Journal of Physical Anthropology",
    abstract = "Abstract The large collections of fossil hominid remains from Hadar, Ethiopia, derive from the Afar Triangle of the continental East African Rift. The fossils constitute much of the paratype series of Australopithecus afarensis (Johanson, White, and Coppens, 1978*). Citations for starred (*) references appear in Appendix 2, Publications. The primitive morphology exhibited by these hominids is consistent with their chronologic placement between 3.0 and 4.0 m.y. This paper provides the geographic, historic, stratigraphic, paleoenvironmental, and systematic background for Hadar fossil hominids described in this volume.",
    url = "https://doi.org/10.1002/ajpa.1330570402",
    doi = "10.1002/ajpa.1330570402",
    openalex = "W2025325197",
    references = "doi101038260293a0"
}

Abstract The upper part of the Pliocene Hadar Formation, central Afar, Ethiopia, has yielded a 40% complete fossil hominid skeleton (A.L. 288‐1, “Lucy”). This specimen is described in detail and selected measurements and illustrations are provided.

@article{doi101002ajpa1330570403,
    author = "Johanson, Donald C. and Lovejoy, C. Owen and Kimbel, William H. and White, Tim D. and Ward, Steven and Bush, Michael E. and Latimer, Bruce M. and Coppens, Yves",
    title = "Morphology of the Pliocene partial hominid skeleton (A.L. 288‐1) from the Hadar formation, Ethiopia",
    year = "1982",
    journal = "American Journal of Physical Anthropology",
    abstract = "Abstract The upper part of the Pliocene Hadar Formation, central Afar, Ethiopia, has yielded a 40\% complete fossil hominid skeleton (A.L. 288‐1, “Lucy”). This specimen is described in detail and selected measurements and illustrations are provided.",
    url = "https://doi.org/10.1002/ajpa.1330570403",
    doi = "10.1002/ajpa.1330570403",
    openalex = "W2123307947",
    references = "doi101017cbo9780511897795, openalexw1516188323"
}

An endocast of the frontal lobe of a reconstructed skull, which is approximately 2 million years old, from the Koobi Fora region of Kenya appears to represent the oldest human-like cortical sulcal pattern in the fossil record, while the endocast from another skull from the same region produces an endocast that appears apelike in its frontal lobe and similar to endocasts from earlier South African australopithecines. New analysis of paleoanatomical evidence thus indicates that at least two taxa of early hominids coexisted in East Africa.

@article{falk1983cerebral,
    author = "Falk, Dean",
    title = "Cerebral Cortices of East African Early Hominids",
    year = "1983",
    journal = "Science",
    abstract = "An endocast of the frontal lobe of a reconstructed skull, which is approximately 2 million years old, from the Koobi Fora region of Kenya appears to represent the oldest human-like cortical sulcal pattern in the fossil record, while the endocast from another skull from the same region produces an endocast that appears apelike in its frontal lobe and similar to endocasts from earlier South African australopithecines. New analysis of paleoanatomical evidence thus indicates that at least two taxa of early hominids coexisted in East Africa.",
    url = "https://doi.org/10.1126/science.221.4615.1072",
    doi = "10.1126/science.221.4615.1072",
    number = "4615",
    openalex = "W1972089338",
    pages = "1072-1074",
    volume = "221",
    references = "doi101001archneurpsyc195202320190169017, doi101002ajpa1330530409, doi101002ajpa1330560105, doi1010079781468441482, doi101016s0047248477800262, doi101038115195a0, doi101038242447a0, doi101038248653a0, doi101038261572a0, doi1043249781315132129"
}

This study has used accurate measurements of crown area and precise assessments of the morphological traits of mandibular molars in an attempt to define the metrical and morphological characteristics of early hominid taxa. A total of 196 Plio-Pleistocene hominid molars were either allocated to one of six informal taxonomic groups or considered as individual cases. Accurate measurements of crown base area made from occlusal photographs have enabled us to estimate the effects of interproximal wear on crown areas. The average correction factor over the three molar types is around 2-4% with a maximum of 6%. The patterns of distribution of extra cusps show interesting differences between taxa. None of the M-1S in the two groups of 'gracile' hominids from East and South Africa bears a C6, but it is common in the two 'robust' taxa. The distribution of a C7 is the reverse of this, it being rare in the robust' taxa, and more common in the 'gracile' groups. There is thus no simple relationship between cusp number and tooth size. Our observations on the protostylid suggest that though it is more common in the 'robust' australopithecines than the 'graciles', when it does occur it is more strongly expressed in the 'gracile' group. The combination of simple metrical data, and the assessment of morphological traits, can help in the classification of enigmatic or incomplete specimens. Some isolated teeth from the collection at Koobi Fora can confidently be assigned to Australopithecus boisei, and useful guides have been provided for taxonomic assessment of the skull KNM-ER 1805, and the mandibles KNM-ER 1506 and 1820.

@article{openalexw1541691368,
    author = "Wood, Bernard and Abbott, S A",
    title = "Analysis of the dental morphology of Plio-pleistocene hominids. I. Mandibular molars: crown area measurements and morphological traits.",
    year = "1983",
    journal = "PubMed",
    abstract = "This study has used accurate measurements of crown area and precise assessments of the morphological traits of mandibular molars in an attempt to define the metrical and morphological characteristics of early hominid taxa. A total of 196 Plio-Pleistocene hominid molars were either allocated to one of six informal taxonomic groups or considered as individual cases. Accurate measurements of crown base area made from occlusal photographs have enabled us to estimate the effects of interproximal wear on crown areas. The average correction factor over the three molar types is around 2-4\% with a maximum of 6\%. The patterns of distribution of extra cusps show interesting differences between taxa. None of the M-1S in the two groups of 'gracile' hominids from East and South Africa bears a C6, but it is common in the two 'robust' taxa. The distribution of a C7 is the reverse of this, it being rare in the robust' taxa, and more common in the 'gracile' groups. There is thus no simple relationship between cusp number and tooth size. Our observations on the protostylid suggest that though it is more common in the 'robust' australopithecines than the 'graciles', when it does occur it is more strongly expressed in the 'gracile' group. The combination of simple metrical data, and the assessment of morphological traits, can help in the classification of enigmatic or incomplete specimens. Some isolated teeth from the collection at Koobi Fora can confidently be assigned to Australopithecus boisei, and useful guides have been provided for taxonomic assessment of the skull KNM-ER 1805, and the mandibles KNM-ER 1506 and 1820.",
    openalex = "W1541691368",
    references = "doi101038248653a0"
}

@article{newman1984early,
    author = "Newman, James L.",
    title = "Early African Hominids: Pedagogic patterns",
    year = "1984",
    journal = "Journal of Geography",
    url = "https://doi.org/10.1080/00221348408980475",
    doi = "10.1080/00221348408980475",
    number = "3",
    openalex = "W2001896103",
    pages = "107-112",
    volume = "83",
    references = "doi101002ajpa1330530202, doi101002ajpa1330530211, doi101002ajpa1330600302, doi101038scientificamerican028250, doi101126science2114480341, doi1015159783110878837477, doi102307143912, doi105281zenodo15915545, johanson1979a, openalexw1666666158"
}

@misc{pilbeam1984the2,
    author = "Pilbeam, D",
    title = "The descent of homonoids and homonids",
    year = "1984",
    howpublished = "Scientific American, v. 250, no. 3, p. 84-96",
    note = "talkorigins\_source = {true}; raw\_reference = {Pilbeam, D., 1984, The descent of homonoids and homonids: Scientific American, v. 250, no. 3, p. 84-96.}"
}

@article{doi101038316788a0,
    author = "Brown, Frank H. and Harris, John and Leakey, Richard E. and Walker, Alan",
    title = "Early Homo erectus skeleton from west Lake Turkana, Kenya",
    year = "1985",
    journal = "Nature",
    url = "https://doi.org/10.1038/316788a0",
    doi = "10.1038/316788a0",
    openalex = "W2091073050",
    references = "doi101002ajpa1330380315, doi101038184491a0"
}

The subocclusal morphology of 168 permanent mandibular premolars (N = 77) and molars (N = 91) of Plio-Pleistocene hominids has been investigated. The taxonomic allocation of the teeth, which represent at least 46 individuals, was based on nondental evidence. Specimens were allocated to one of two major taxonomic categories, (EAFROB or EAFHOM), East African Homo erectus (EAFHER), or their taxonomic affinity was regarded as 'unknown' (N = 17). Information about the root system was derived from radiography and direct observation. Morphometric data were in the form of nine linear and two angular measurements based on eighteen reference points. Root form was also assessed using a scheme which recognised four classes of root morphology. Data were compared using both univariate and multivariate techniques, including Principal Component and Canonical Variate analysis. Posterior probabilities derived from the latter were used (in a two-taxon design model) to assess the affinities of the 'unknown' specimens. The variation in hominid mandibular premolar root form was interpreted as two morphoclines, based on the presumed primitive condition of the P3 (with mesiobuccal and distal roots, 2R: MB and D) and P4 (with mesial and distal root, 2R: M and D) root systems. One trend apparently leads towards root reduction (i.e. P3 = 1 R; P4 = 1 R), and the other to root elaboration (i.e. P3 and P4 = 2R: M and D). The extreme form of the latter is the 'molarisation' of the premolar roots seen in EAFROB. Despite major differences in root form there was relatively little taxonomic variation in root metrics, except for a more robust distal root system in EAFROB. Molar root form showed little interspecific variation except for M2 in which the roots in EAFROB were larger and more robust, with differences in root height being greater for the distal than for the mesial roots. Root form and metrics enable four of the 'unknown' specimens (KMN-ER 819, 1482, 1483 and 1801) to be tentatively allocated to EAFHOM, and a single specimen, KMN-ER 3731, to EAFROB. Published assessments of the root morphology of the 'robust' australopithecines from Swartkrans suggest that the premolar root form of Australopithecus (Paranthropus) robustus is not obviously intermediate between the presumed ancestral condition, and the 'molarised' mandibular premolar root systems of Australopithecus (Paranthropus) boisei.

@article{openalexw1512152518,
    author = "Wood, Bernard and Abbott, S A and Uytterschaut, Hilde",
    title = "Analysis of the dental morphology of Plio-Pleistocene hominids. IV. Mandibular postcanine root morphology.",
    year = "1988",
    journal = "PubMed",
    abstract = "The subocclusal morphology of 168 permanent mandibular premolars (N = 77) and molars (N = 91) of Plio-Pleistocene hominids has been investigated. The taxonomic allocation of the teeth, which represent at least 46 individuals, was based on nondental evidence. Specimens were allocated to one of two major taxonomic categories, (EAFROB or EAFHOM), East African Homo erectus (EAFHER), or their taxonomic affinity was regarded as 'unknown' (N = 17). Information about the root system was derived from radiography and direct observation. Morphometric data were in the form of nine linear and two angular measurements based on eighteen reference points. Root form was also assessed using a scheme which recognised four classes of root morphology. Data were compared using both univariate and multivariate techniques, including Principal Component and Canonical Variate analysis. Posterior probabilities derived from the latter were used (in a two-taxon design model) to assess the affinities of the 'unknown' specimens. The variation in hominid mandibular premolar root form was interpreted as two morphoclines, based on the presumed primitive condition of the P3 (with mesiobuccal and distal roots, 2R: MB and D) and P4 (with mesial and distal root, 2R: M and D) root systems. One trend apparently leads towards root reduction (i.e. P3 = 1 R; P4 = 1 R), and the other to root elaboration (i.e. P3 and P4 = 2R: M and D). The extreme form of the latter is the 'molarisation' of the premolar roots seen in EAFROB. Despite major differences in root form there was relatively little taxonomic variation in root metrics, except for a more robust distal root system in EAFROB. Molar root form showed little interspecific variation except for M2 in which the roots in EAFROB were larger and more robust, with differences in root height being greater for the distal than for the mesial roots. Root form and metrics enable four of the 'unknown' specimens (KMN-ER 819, 1482, 1483 and 1801) to be tentatively allocated to EAFHOM, and a single specimen, KMN-ER 3731, to EAFROB. Published assessments of the root morphology of the 'robust' australopithecines from Swartkrans suggest that the premolar root form of Australopithecus (Paranthropus) robustus is not obviously intermediate between the presumed ancestral condition, and the 'molarised' mandibular premolar root systems of Australopithecus (Paranthropus) boisei.",
    openalex = "W1512152518",
    references = "doi101038248653a0"
}

The discovery of several associated body parts of early hominids whose taxonomic identity is known inspires this study of body size and proportions in early hominids. The approach consists of finding the relationship between various measures of skeletal size and body mass in modern ape and human specimens of known body weight. This effort leads to 78 equations which predict body weight from 95 fossil specimens ranging in geological age between 4 and 1.4 mya. Predicted weights range from 10 kg to over 160 kg, but the partial associated skeletons provide the essential clues as to which predictions are most reliable. Measures of hindlimb joint size are the best and probably those equations based on the human samples are better than those based on all Hominoidea. Using hindlimb joint size of specimens of relatively certain taxonomy and assuming these measures were more like those of modern humans than of apes, the male and female averages are as follows: Australopithecus afarensis, 45 and 29 kg; A. africanus, 41 and 30 kg; A. robustus, 40 and 32 kg; A. boisei, 49 and 34 kg; H. habilis, 52 and 32 kg. These values appear to be consistent with the range of size variation seen in the entire postcranial samples that can be assigned to species. If hominoid (i.e., ape and human combined) proportions are assumed, the males would be 10 to 23 kg larger and the females 4 to 10 kg larger.

@article{doi101002ajpa1330870404,
    author = "McHenry, Henry M.",
    title = "Body size and proportions in early hominids",
    year = "1992",
    journal = "American Journal of Physical Anthropology",
    abstract = "The discovery of several associated body parts of early hominids whose taxonomic identity is known inspires this study of body size and proportions in early hominids. The approach consists of finding the relationship between various measures of skeletal size and body mass in modern ape and human specimens of known body weight. This effort leads to 78 equations which predict body weight from 95 fossil specimens ranging in geological age between 4 and 1.4 mya. Predicted weights range from 10 kg to over 160 kg, but the partial associated skeletons provide the essential clues as to which predictions are most reliable. Measures of hindlimb joint size are the best and probably those equations based on the human samples are better than those based on all Hominoidea. Using hindlimb joint size of specimens of relatively certain taxonomy and assuming these measures were more like those of modern humans than of apes, the male and female averages are as follows: Australopithecus afarensis, 45 and 29 kg; A. africanus, 41 and 30 kg; A. robustus, 40 and 32 kg; A. boisei, 49 and 34 kg; H. habilis, 52 and 32 kg. These values appear to be consistent with the range of size variation seen in the entire postcranial samples that can be assigned to species. If hominoid (i.e., ape and human combined) proportions are assumed, the males would be 10 to 23 kg larger and the females 4 to 10 kg larger.",
    url = "https://doi.org/10.1002/ajpa.1330870404",
    doi = "10.1002/ajpa.1330870404",
    openalex = "W2088101833",
    references = "doi101002ajpa1330490407, doi101038202007a0, doi101038248653a0, doi101126science1864167892, doi1023072800701, doi105860choice290302"
}

Miocene hominoids from Europe are among the earliest members of the great ape and human clade (the Hominidae). One of these forms, represented by well-preserved cranial remains from Rudabánya, Hungary, sheds new light on the question of the evolutionary relations among living hominids. This new evidence supports the view that humans have a specific evolutionary relation with chimpanzees, to the exclusion of all other apes.

@article{doi101126science1411507,
    author = "Begun, David R.",
    title = "Miocene Fossil Hominids and the Chimp-Human Clade",
    year = "1992",
    journal = "Science",
    abstract = "Miocene hominoids from Europe are among the earliest members of the great ape and human clade (the Hominidae). One of these forms, represented by well-preserved cranial remains from Rudabánya, Hungary, sheds new light on the question of the evolutionary relations among living hominids. This new evidence supports the view that humans have a specific evolutionary relation with chimpanzees, to the exclusion of all other apes.",
    url = "https://doi.org/10.1126/science.1411507",
    doi = "10.1126/science.1411507",
    openalex = "W1975586897"
}

Hominids—both living and past—exhibit considerable variation in body size and shape. Both theoretical considerations and empirical observations indicate that some of this variation may be attributable to climatic adaptation. Application of the simple thermoregulatory principle of increasing and decreasing body surface area/body mass in hot and cold climates, respectively, may explain the major systematic differences in body form between living and fossil hominids inhabiting tropical and higher latitude regions of the world. Consideration of potential climatic influences on morphology has important ramifications for reconstructing body form and behavior of past hominids, interpreting geographic and temporal variability and migrational events, explaining the origins and perfection of hominid bipedalism, and better understanding changes in brain size and encephalization during hominid evolution. © 1994 Wiley-Liss, Inc.

@article{doi101002ajpa1330370605,
    author = "Ruff, Christopher B.",
    title = "Morphological adaptation to climate in modern and fossil hominids",
    year = "1994",
    journal = "American Journal of Physical Anthropology",
    abstract = "Hominids—both living and past—exhibit considerable variation in body size and shape. Both theoretical considerations and empirical observations indicate that some of this variation may be attributable to climatic adaptation. Application of the simple thermoregulatory principle of increasing and decreasing body surface area/body mass in hot and cold climates, respectively, may explain the major systematic differences in body form between living and fossil hominids inhabiting tropical and higher latitude regions of the world. Consideration of potential climatic influences on morphology has important ramifications for reconstructing body form and behavior of past hominids, interpreting geographic and temporal variability and migrational events, explaining the origins and perfection of hominid bipedalism, and better understanding changes in brain size and encephalization during hominid evolution. © 1994 Wiley-Liss, Inc.",
    url = "https://doi.org/10.1002/ajpa.1330370605",
    doi = "10.1002/ajpa.1330370605",
    openalex = "W2004116172",
    references = "doi101007bf02547562, doi101016s0047248484800792, doi101038331614a0, doi1023072800701, doi102307588281, openalexw3207143292"
}

@article{doi101038371306a0,
    author = "White, Tim D. and Suwa, Gen and Asfaw, Berhane",
    title = "Australopithecus ramidus, a new species of early hominid from Aramis, Ethiopia",
    year = "1994",
    journal = "Nature",
    url = "https://doi.org/10.1038/371306a0",
    doi = "10.1038/371306a0",
    openalex = "W2073859880",
    references = "doi101007bf02101694, doi101038360641a0, doi101038366261a0, doi101038371330a0, doi101098rstb19910109, doi101126science1411507, doi101126science15838051200, doi101126science2114480341, doi101144gsljgs1949105010409, johanson1979a"
}

@article{doi101038371330a0,
    author = "WoldeGabriel, Giday and White, Tim D. and Suwa, Gen and Renne, Paul R. and de Heinzelin, Jean and Hart, William K. and Heiken, Grant",
    title = "Ecological and temporal placement of early Pliocene hominids at Aramis, Ethiopia",
    year = "1994",
    journal = "Nature",
    url = "https://doi.org/10.1038/371330a0",
    doi = "10.1038/371330a0",
    openalex = "W1985131644",
    references = "doi1023072803270"
}

@article{doi101038373509a0,
    author = "Gabunia, Leo and Vekua, Abesalom",
    title = "A Plio-Pleistocene hominid from Dmanisi, East Georgia, Caucasus",
    year = "1995",
    journal = "Nature",
    url = "https://doi.org/10.1038/373509a0",
    doi = "10.1038/373509a0",
    openalex = "W2029964302"
}

@article{doi101038376565a0,
    author = "Leakey, Meave G. and Feibel, Craig S. and McDougall, Ian and Walker, Alan",
    title = "New four-million-year-old hominid species from Kanapoi and Allia Bay, Kenya",
    year = "1995",
    journal = "Nature",
    url = "https://doi.org/10.1038/376565a0",
    doi = "10.1038/376565a0",
    openalex = "W1972864325",
    references = "doi101038371306a0, doi1023072803270"
}

Four articulating hominid foot bones have been recovered from Sterkfontein Member 2, near Johannesburg, South Africa. They have human features in the hindfoot and strikingly apelike traits in the forefoot. While the foot is manifestly adapted for bipedalism, its most remarkable characteristic is that the great toe (hallux) is appreciably medially diverged (varus) and strongly mobile, as in apes. Possibly as old as 3.5 million years, the foot provides the first evidence that bipedal hominids were in southern Africa more than 3.0 million years ago. The bones probably belonged to an early member of Australopithecus africanus or another early hominid species.

@article{doi101126science7624772,
    author = "Clarke, Ronald J. and Tobias, Phillip V.",
    title = "Sterkfontein Member 2 Foot Bones of the Oldest South African Hominid",
    year = "1995",
    journal = "Science",
    abstract = "Four articulating hominid foot bones have been recovered from Sterkfontein Member 2, near Johannesburg, South Africa. They have human features in the hindfoot and strikingly apelike traits in the forefoot. While the foot is manifestly adapted for bipedalism, its most remarkable characteristic is that the great toe (hallux) is appreciably medially diverged (varus) and strongly mobile, as in apes. Possibly as old as 3.5 million years, the foot provides the first evidence that bipedal hominids were in southern Africa more than 3.0 million years ago. The bones probably belonged to an early member of Australopithecus africanus or another early hominid species.",
    url = "https://doi.org/10.1126/science.7624772",
    doi = "10.1126/science.7624772",
    openalex = "W2073905748",
    references = "doi101038254301a0"
}

The vertical-climbing account of the evolution of locomotor behavior and morphology in hominid ancestry is reexamined in light of recent behavioral, anatomical, and paleontological findings and a more firmly established phylogeny for the living apes. The behavioral record shows that African apes, when arboreal, are good vertical climbers, and that locomotion during traveling best separates the living apes into brachiators (gibbons), scrambling/ climbing/brachiators (orangutans), and terrestrial quadrupeds (gorillas and chimpanzees). The paleontological record documents frequent climbing as an ancestral catarrhine ability, while a reassessment of the morphology of the torso and forelimb in living apes and Atelini suggests that their shared unique morphological pattern is best explained by brachiation and forelimb suspensory positional behavior. Further, evidence from the hand and foot points to a terrestrial quadrupedal phase in hominoid evolution prior to the adoption of bipedalism. The evolution of positional behavior from early hominoids to hominids appears to have begun with an arboreal quadrupedal-climbing phase and proceeded though an orthograde, brachiating, forelimb-suspensory phase, which was in turn followed by arboreal and terrestrial quadrupedal phases prior to the advent of hominid bipedality. The thesis that protohominids climbed down from the trees to become terrestrial bipeds needs to be reexamined in light of a potentially long history of terrestriality in the ancestral protohominid.

@article{doi101002sici10968644199609101155aidajpa530co2c,
    author = "Gebo, Daniel L.",
    title = "Climbing, brachiation, and terrestrial quadrupedalism: Historical precursors of hominid bipedalism",
    year = "1996",
    journal = "American Journal of Physical Anthropology",
    abstract = "The vertical-climbing account of the evolution of locomotor behavior and morphology in hominid ancestry is reexamined in light of recent behavioral, anatomical, and paleontological findings and a more firmly established phylogeny for the living apes. The behavioral record shows that African apes, when arboreal, are good vertical climbers, and that locomotion during traveling best separates the living apes into brachiators (gibbons), scrambling/ climbing/brachiators (orangutans), and terrestrial quadrupeds (gorillas and chimpanzees). The paleontological record documents frequent climbing as an ancestral catarrhine ability, while a reassessment of the morphology of the torso and forelimb in living apes and Atelini suggests that their shared unique morphological pattern is best explained by brachiation and forelimb suspensory positional behavior. Further, evidence from the hand and foot points to a terrestrial quadrupedal phase in hominoid evolution prior to the adoption of bipedalism. The evolution of positional behavior from early hominoids to hominids appears to have begun with an arboreal quadrupedal-climbing phase and proceeded though an orthograde, brachiating, forelimb-suspensory phase, which was in turn followed by arboreal and terrestrial quadrupedal phases prior to the advent of hominid bipedality. The thesis that protohominids climbed down from the trees to become terrestrial bipeds needs to be reexamined in light of a potentially long history of terrestriality in the ancestral protohominid.",
    url = "https://doi.org/10.1002/(sici)1096-8644(199609)101:1<55::aid-ajpa5>3.0.co;2-c",
    doi = "10.1002/(sici)1096-8644(199609)101:1<55::aid-ajpa5>3.0.co;2-c",
    openalex = "W2038925787",
    references = "doi101002aja1001370304, doi101007978148993647916, doi101038196409a0, doi101086397067"
}

@article{doi101006jhev19960097,
    author = "Strait, David S. and Grine, Frederick E. and Moniz, Marc A.",
    title = "A reappraisal of early hominid phylogeny",
    year = "1997",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1006/jhev.1996.0097",
    doi = "10.1006/jhev.1996.0097",
    openalex = "W1974669442",
    references = "conroy1990endocranial, doi101002ajpa1330700205, doi101002ajpa1330700306, doi101007978146848854829, doi101007bf02547562, doi101086203377, doi101093sysbio1811, doi101111j109600311989tb00573x, doi101111j155856461982tb05453x, doi101146annureven10010165000525, doi1023071377078, doi1023072412407, doi1023072412606, doi105860choice392183, doi107312simp92414, openalexw2506868775, openalexw3034932225, openalexw638862129"
}

@article{doi101006jhev19960102,
    author = "Spencer, Lillian M.",
    title = "Dietary adaptations of Plio-Pleistocene Bovidae: implications for hominid habitat use",
    year = "1997",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1006/jhev.1996.0102",
    doi = "10.1006/jhev.1996.0102",
    openalex = "W1986855259",
    references = "doi101038142377a0"
}

@article{doi101006jhev19960106,
    author = "Reed, Kaye E.",
    title = "Early hominid evolution and ecological change through the African Plio-Pleistocene",
    year = "1997",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1006/jhev.1996.0106",
    doi = "10.1006/jhev.1996.0106",
    openalex = "W2053736750",
    references = "doi101002ajpa1330600302, doi10100797814899503456, doi101016s0047248477800262, doi101038115195a0, doi101038254301a0, doi10108002724634198710011651, doi1023072803270, doi1023073515582, doi1043249780203792667, doi105860choice291525, doi105860choice300309"
}

Variability selection (abbreviated as VS) is a process considered to link adaptive change to large degrees of environment variability. Its application to hominid evolution is based, in part, on the pronounced rise in environmental remodeling that took place over the past several million years. The VS hypothesis differs from prior views of hominid evolution, which stress the consistent selective effects associated with specific habitats or directional trends (e.g., woodland, savanna expansion, cooling). According to the VS hypothesis, wide fluctuations over time created a growing disparity in adaptive conditions. Inconsistency in selection eventually caused habitat-specific adaptations to be replaced by structures and behaviors responsive to complex environmental change. Key hominid adaptations, in fact, emerged during times of heightened variability. Early bipedality, encephalized brains, and complex human sociality appear to signify a sequence of VS adaptations—i.e., a ratcheting up of versatility and responsiveness to novel environments experienced over the past 6 million years. The adaptive results of VS cannot be extrapolated from selection within a single environmental shift or relatively stable habitat. If some complex traits indeed require disparities in adaptive setting (and relative fitness) in order to evolve, the VS idea counters the prevailing view that adaptive change necessitates long-term, directional consistency in selection. © 1998 Wiley-Liss, Inc.

@article{doi101002sici1520650519987381aidevan330co2a,
    author = "Potts, Richard",
    title = "Variability selection in hominid evolution",
    year = "1998",
    journal = "Evolutionary Anthropology Issues News and Reviews",
    abstract = "Variability selection (abbreviated as VS) is a process considered to link adaptive change to large degrees of environment variability. Its application to hominid evolution is based, in part, on the pronounced rise in environmental remodeling that took place over the past several million years. The VS hypothesis differs from prior views of hominid evolution, which stress the consistent selective effects associated with specific habitats or directional trends (e.g., woodland, savanna expansion, cooling). According to the VS hypothesis, wide fluctuations over time created a growing disparity in adaptive conditions. Inconsistency in selection eventually caused habitat-specific adaptations to be replaced by structures and behaviors responsive to complex environmental change. Key hominid adaptations, in fact, emerged during times of heightened variability. Early bipedality, encephalized brains, and complex human sociality appear to signify a sequence of VS adaptations—i.e., a ratcheting up of versatility and responsiveness to novel environments experienced over the past 6 million years. The adaptive results of VS cannot be extrapolated from selection within a single environmental shift or relatively stable habitat. If some complex traits indeed require disparities in adaptive setting (and relative fitness) in order to evolve, the VS idea counters the prevailing view that adaptive change necessitates long-term, directional consistency in selection. © 1998 Wiley-Liss, Inc.",
    url = "https://doi.org/10.1002/(sici)1520-6505(1998)7:3<81::aid-evan3>3.0.co;2-a",
    doi = "10.1002/(sici)1520-6505(1998)7:3<81::aid-evan3>3.0.co;2-a",
    openalex = "W2025328236",
    references = "doi101007bf02547562, doi101038371306a0, doi101038scientificamerican096062"
}

Palaeoanthropological systematics is principally concerned with the identification and formal recognition of natural groups among the fossil specimens that belong to the human lineage. It aims, in other words, to divide the fossil hominids into taxa that are the result of biological processes rather than abstractions of the human mind.

@incollection{collard1999grades,
    author = "Collard, Mark and Wood, Bernard",
    title = "Grades among the African Early Hominids",
    year = "1999",
    booktitle = "African Biogeography, Climate Change, \& Human Evolution",
    abstract = "Palaeoanthropological systematics is principally concerned with the identification and formal recognition of natural groups among the fossil specimens that belong to the human lineage. It aims, in other words, to divide the fossil hominids into taxa that are the result of biological processes rather than abstractions of the human mind.",
    url = "https://doi.org/10.1093/oso/9780195114379.003.0023",
    doi = "10.1093/oso/9780195114379.003.0023",
    openalex = "W1923507826",
    pages = "316-327"
}

Current consensus holds that the 3-million-year-old hominid Australopithecus africanus subsisted on fruits and leaves, much as the modern chimpanzee does. Stable carbon isotope analysis of A. africanus from Makapansgat Limeworks, South Africa, demonstrates that this early hominid ate not only fruits and leaves but also large quantities of carbon-13-enriched foods such as grasses and sedges or animals that ate these plants, or both. The results suggest that early hominids regularly exploited relatively open environments such as woodlands or grasslands for food. They may also suggest that hominids consumed high-quality animal foods before the development of stone tools and the origin of the genus Homo.

@article{doi101126science2835400368,
    author = "Sponheimer, Matt and Lee‐Thorp, Julia A.",
    title = "Isotopic Evidence for the Diet of an Early Hominid, Australopithecus africanus",
    year = "1999",
    journal = "Science",
    abstract = "Current consensus holds that the 3-million-year-old hominid Australopithecus africanus subsisted on fruits and leaves, much as the modern chimpanzee does. Stable carbon isotope analysis of A. africanus from Makapansgat Limeworks, South Africa, demonstrates that this early hominid ate not only fruits and leaves but also large quantities of carbon-13-enriched foods such as grasses and sedges or animals that ate these plants, or both. The results suggest that early hominids regularly exploited relatively open environments such as woodlands or grasslands for food. They may also suggest that hominids consumed high-quality animal foods before the development of stone tools and the origin of the genus Homo.",
    url = "https://doi.org/10.1126/science.283.5400.368",
    doi = "10.1126/science.283.5400.368",
    openalex = "W2081962176",
    references = "doi101017cbo9780511897795"
}

The lack of an adequate hominid fossil record in eastern Africa between 2 and 3 million years ago (Ma) has hampered investigations of early hominid phylogeny. Discovery of 2.5 Ma hominid cranial and dental remains from the Hata beds of Ethiopia's Middle Awash allows recognition of a new species of Australopithecus. This species is descended from Australopithecus afarensis and is a candidate ancestor for early Homo. Contemporary postcranial remains feature a derived humanlike humeral/femoral ratio and an apelike upper arm-to-lower arm ratio.

@article{doi101126science2845414629,
    author = "Asfaw, Berhane and White, Tim D. and Lovejoy, Owen and Latimer, Bruce and Simpson, Scott W. and Suwa, Gen",
    title = "Australopithecus garhi: A New Species of Early Hominid from Ethiopia",
    year = "1999",
    journal = "Science",
    abstract = "The lack of an adequate hominid fossil record in eastern Africa between 2 and 3 million years ago (Ma) has hampered investigations of early hominid phylogeny. Discovery of 2.5 Ma hominid cranial and dental remains from the Hata beds of Ethiopia's Middle Awash allows recognition of a new species of Australopithecus. This species is descended from Australopithecus afarensis and is a candidate ancestor for early Homo. Contemporary postcranial remains feature a derived humanlike humeral/femoral ratio and an apelike upper arm-to-lower arm ratio.",
    url = "https://doi.org/10.1126/science.284.5414.629",
    doi = "10.1126/science.284.5414.629",
    openalex = "W2058867855",
    references = "doi101006jhev19960097, doi101126science2845414625"
}

PART I. THEORY PART II. GEOLOGY, ECOLOGY, AND BIOGEOGRAPHY PART III. FOSSIL FAUNAS PART IV. HOMINID EVOLUTION

@book{openalexw655043828,
    author = "Bromage, Timothy G. and Schrenk, Friedemann",
    title = "African biogeography, climate change, \& human evolution",
    year = "1999",
    booktitle = "Oxford University Press eBooks",
    abstract = "PART I. THEORY PART II. GEOLOGY, ECOLOGY, AND BIOGEOGRAPHY PART III. FOSSIL FAUNAS PART IV. HOMINID EVOLUTION",
    openalex = "W655043828"
}

@article{vogel1999did,
    author = "Vogel, Gretchen",
    title = "Did Early African Hominids Eat Meat?",
    year = "1999",
    journal = "Science",
    url = "https://doi.org/10.1126/science.283.5400.303",
    doi = "10.1126/science.283.5400.303",
    number = "5400",
    openalex = "W1526462990",
    pages = "303-303",
    volume = "283"
}

@article{doi101006jhev19990392,
    author = "Kuman, Kathleen and Clarke, Ronald J.",
    title = "Stratigraphy, artefact industries and hominid associations for Sterkfontein, Member 5",
    year = "2000",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1006/jhev.1999.0392",
    doi = "10.1006/jhev.1999.0392",
    openalex = "W2086255993",
    references = "doi101007bf02547562, doi101038254301a0, openalexw3034932225"
}

Archaeological excavations at the site of Dmanisi in the Republic of Georgia have uncovered two partial early Pleistocene hominid crania. The new fossils consist of a relatively complete cranium and a second relatively complete calvaria from the same site and stratigraphic unit that yielded a hominid mandible in 1991. In contrast with the uncertain taxonomic affinity of the mandible, the new fossils are comparable in size and morphology with Homo ergaster from Koobi Fora, Kenya. Paleontological, archaeological, geochronological, and paleomagnetic data from Dmanisi all indicate an earliest Pleistocene age of about 1.7 million years ago, supporting correlation of the new specimens with the Koobi Fora fossils. The Dmanisi fossils, in contrast with Pleistocene hominids from Western Europe and Eastern Asia, show clear African affinity and may represent the species that first migrated out of Africa.

@article{doi101126science28854681019,
    author = "Gabunia, Leo and Vekua, Abesalom and Lordkipanidze, David and Swisher, Carl C. and Ferring, Reid and Justus, Antje and Nioradzé, Médéa and Tvalchrelidze, Merab and Antón, Susan C. and Bosinski, Gerhard and Jöris, Olaf and Lumley, Marie-A.-de and Majsuradze, Givi and Mouskhelishvili, Aleksander",
    title = "Earliest Pleistocene Hominid Cranial Remains from Dmanisi, Republic of Georgia: Taxonomy, Geological Setting, and Age",
    year = "2000",
    journal = "Science",
    abstract = "Archaeological excavations at the site of Dmanisi in the Republic of Georgia have uncovered two partial early Pleistocene hominid crania. The new fossils consist of a relatively complete cranium and a second relatively complete calvaria from the same site and stratigraphic unit that yielded a hominid mandible in 1991. In contrast with the uncertain taxonomic affinity of the mandible, the new fossils are comparable in size and morphology with Homo ergaster from Koobi Fora, Kenya. Paleontological, archaeological, geochronological, and paleomagnetic data from Dmanisi all indicate an earliest Pleistocene age of about 1.7 million years ago, supporting correlation of the new specimens with the Koobi Fora fossils. The Dmanisi fossils, in contrast with Pleistocene hominids from Western Europe and Eastern Asia, show clear African affinity and may represent the species that first migrated out of Africa.",
    url = "https://doi.org/10.1126/science.288.5468.1019",
    doi = "10.1126/science.288.5468.1019",
    openalex = "W2100804798",
    references = "doi101016s0009254197001599, doi101038385333a0"
}

@article{doi101016s1251805001015294,
    author = "Sénut, Brigitte and Pickford, Martin and Gommery, Dominique and Mein, P. and Cheboi, Kiptalam and Coppens, Yves",
    title = "First hominid from the Miocene (Lukeino Formation, Kenya)",
    year = "2001",
    journal = "Comptes Rendus de l Académie des Sciences - Series IIA - Earth and Planetary Science",
    url = "https://doi.org/10.1016/s1251-8050(01)01529-4",
    doi = "10.1016/s1251-8050(01)01529-4",
    openalex = "W2045371328",
    references = "doi101002ajpa1330600302, doi101038371306a0"
}

@article{doi10103835084063,
    author = "Haile‐Selassie, Yohannes",
    title = "Late Miocene hominids from the Middle Awash, Ethiopia",
    year = "2001",
    journal = "Nature",
    url = "https://doi.org/10.1038/35084063",
    doi = "10.1038/35084063",
    openalex = "W1658559065",
    references = "doi101002ajpa1330570412, doi101007bf02735291, doi101016s1251805001015282, doi101016s1251805001015294, doi10103835084058, doi101038371306a0, doi101073pnas922532, doi10108002724634199610011339, doi101086318206, doi101093oxfordjournalsmolbeva025761"
}

A variety of topics which play important roles in the systematics of fossil hominids are discussed. One of the major ontological/theoretical issues that influence the empirical work of species level taxonomy concerns the assumption that fossil hominid samples can be axiomatically considered terminal taxa. Another axiomatized practice is that of employing operational taxonomic units (OTUs) whereby nearly all samples of any level of distinction are considered valid species taxa. These unsubstantiated assumptions, coupled with punctuationist notions of species origin, intertwine to form a practice which results in a taxonomic distortion of what the probable evolutionary realities of evolving lineages were. The selection of extant taxonomic model species for delineating hominid species taxa has been a major issue of contention, and it will continue as long as observed ranges that include all known populations of any one single living hominoid model species continue to be ignored. Paleontological species taxa do not necessarily represent new lineages, but the iconography of taxograms (based on the practices noted) which routinely assume the latter to be phylogenetic trees imply a multitude of closed lineages. Such imagery is probably much more of an artifact than a tested reality of hominid evolutionary history. Examples are discussed. Key words: Taxonomic assumptions, phylogenetics, punctuationism, species taxa, lineages, paleoanthropology, stage vs. grade.

@article{openalexw3159467142,
    author = "Szalay, Frederick S.",
    title = "Problems with hominid fossil species taxa and the construction of taxograms",
    year = "2001",
    abstract = "A variety of topics which play important roles in the systematics of fossil hominids are discussed. One of the major ontological/theoretical issues that influence the empirical work of species level taxonomy concerns the assumption that fossil hominid samples can be axiomatically considered terminal taxa. Another axiomatized practice is that of employing operational taxonomic units (OTUs) whereby nearly all samples of any level of distinction are considered valid species taxa. These unsubstantiated assumptions, coupled with punctuationist notions of species origin, intertwine to form a practice which results in a taxonomic distortion of what the probable evolutionary realities of evolving lineages were. The selection of extant taxonomic model species for delineating hominid species taxa has been a major issue of contention, and it will continue as long as observed ranges that include all known populations of any one single living hominoid model species continue to be ignored. Paleontological species taxa do not necessarily represent new lineages, but the iconography of taxograms (based on the practices noted) which routinely assume the latter to be phylogenetic trees imply a multitude of closed lineages. Such imagery is probably much more of an artifact than a tested reality of hominid evolutionary history. Examples are discussed. Key words: Taxonomic assumptions, phylogenetics, punctuationism, species taxa, lineages, paleoanthropology, stage vs. grade.",
    openalex = "W3159467142",
    references = "collard1999grades, doi101002sici152065052000912aidevan230co22, doi10100797814899374524, doi1010079783662033685, doi101111j109583121998tb01535x, doi1023072806339, doi105281zenodo5374203, doi105860choice325665, openalexw1516188323, openalexw655043828, openalexw659460302"
}

@article{doi101038nature00879,
    author = "Brunet, Michel and Guy, Franck and Pilbeam, David and Mackaye, Hassane Taïsso and Likius, Andossa and Djimdoumalbaye, Ahounta and Beauvilain, Alain and Blondel, Cécile and Bocherens, Hervé and Boisserie, Jean‐Renaud and de Bonis, Louis and Coppens, Yves and Dejax, Jean and Denys, Christiane and Duringer, Philippe and Eisenmann, Véra and Fanone, Gongdibé and Fronty, Pierre and Geraads, Denis and Lehmann, Thomas and Lihoreau, Fabrice and Louchart, Antoine and Mahamat, Adoum and Merceron, Gildas and Mouchelin, Guy and Otero, Olga and Peláez‐Campomanes, Pablo and de León, Marcia S. Ponce and Rage, Jean‐Claude and Sapanet, Michel and Schuster, Mathieu and Sudre, Jean and Tassy, Pascal and Valentin, Xavier and Vignaud, Patrick and Viriot, Laurent and Zazzo, Antoine and Zollikofer, Christoph P. E.",
    title = "A new hominid from the Upper Miocene of Chad, Central Africa",
    year = "2002",
    journal = "Nature",
    url = "https://doi.org/10.1038/nature00879",
    doi = "10.1038/nature00879",
    openalex = "W2119640985",
    references = "doi101016s0764444200017869, doi101017cbo9780511897795, doi101038115195a0, doi10103831927, doi10103835084063, doi10103835093050, doi101038371306a0, doi101073pnas061035098, doi101146annurevcellbio141167, doi101152jappl1972333312, doi101152jappl20019031137, doi101152physrev1991712541, doi101172jci10268"
}

@article{doi101016jjhevol200311004,
    author = "Wood, Bernard and Strait, David S.",
    title = "Patterns of resource use in early Homo and Paranthropus",
    year = "2003",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1016/j.jhevol.2003.11.004",
    doi = "10.1016/j.jhevol.2003.11.004",
    openalex = "W2110365920",
    references = "doi101006jhev19980239, doi101038142377a0, doi1023072406439, openalexw3034932225"
}

@article{doi101016jjhevol200505007,
    author = "Laden, Greg and Wrangham, Richard W.",
    title = "The rise of the hominids as an adaptive shift in fallback foods: Plant underground storage organs (USOs) and australopith origins",
    year = "2005",
    journal = "Journal of Human Evolution",
    url = "https://doi.org/10.1016/j.jhevol.2005.05.007",
    doi = "10.1016/j.jhevol.2005.05.007",
    openalex = "W2071530361",
    references = "doi101006jhev19980239, doi101016s0047248477800262, doi101017chol9780521222150005"
}

@article{doi101038nature03392,
    author = "Brunet, Michel and Guy, Franck and Pilbeam, David and Lieberman, Daniel E. and Likius, Andossa and Mackaye, Hassane Taïsso and de León, Marcia S. Ponce and Zollikofer, Christoph P. E. and Vignaud, Patrick",
    title = "New material of the earliest hominid from the Upper Miocene of Chad",
    year = "2005",
    journal = "Nature",
    url = "https://doi.org/10.1038/nature03392",
    doi = "10.1038/nature03392",
    openalex = "W2106767469",
    references = "doi101016s0764444200017869"
}

@article{doi101038nature06134,
    author = "Lordkipanidze, David and Jashashvili, Tea and Vekua, Abesalom and de León, Marcia S. Ponce and Zollikofer, Christoph P. E. and Rightmire, G. Philip and Pontzer, Herman and Ferring, Reid and Oms, Oriol and Tappen, Martha and Bukhsianidze, Maia and Agustı́, Jordi and Kahlke, Ralf and Kiladze, Gocha and Martı́nez-Navarro, Bienvenido and Mouskhelishvili, Alexander and Nioradzé, Médéa and Rook, Lorenzo",
    title = "Postcranial evidence from early Homo from Dmanisi, Georgia",
    year = "2007",
    journal = "Nature",
    url = "https://doi.org/10.1038/nature06134",
    doi = "10.1038/nature06134",
    openalex = "W2041683415",
    references = "doi101002ajpa1330570403, doi101002ajpa1330600302, doi101002ajpa1330780412, doi101002ajpa1330870404, doi101016c2009002515x, doi101038202007a0, doi101038260293a0, doi101038nature02999, doi101038nature03052, doi101126science28854681019, doi101242jeb02662"
}

Ages were determined at two hominid localities from the Chad Basin in the Djurab Desert (Northern Chad). In the Koro Toro fossiliferous area, KT 12 locality (16 degrees 00'N, 18 degrees 53'E) was the site of discovery of Australopithecus bahrelghazali (Abel) and in the Toros-Menalla fossiliferous area, TM 266 locality (16 degrees 15'N, 17 degrees 29'E) was the site of discovery of Sahelanthropus tchadensis (Toumaï). At both localities, the evolutive degree of the associated fossil mammal assemblages allowed a biochronological estimation of the hominid remains: early Pliocene (3-3.5 Ma) at KT 12 and late Miocene (approximately 7 Ma) at TM 266. Atmospheric (10)Be, a cosmogenic nuclide, was used to quasicontinuously date these sedimentary units. The authigenic (10)Be/(9)Be dating of a pelite relic within the sedimentary level containing Abel yields an age of 3.58 +/- 0.27 Ma that points to the contemporaneity of Australopithecus bahrelghazali (Abel) with Australopithecus afarensis (Lucy). The 28 (10)Be/(9)Be ages obtained within the anthracotheriid unit containing Toumaï bracket, by absolute dating, the age of Sahelanthropus tchadensis to lie between 6.8 and 7.2 Ma. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock.

@article{doi101073pnas0708015105,
    author = "Lebatard, Anne-Élisabeth and Bourlès, Didier and Duringer, Philippe and Jolivet, Marc and Braucher, Régis and Carcaillet, Julien and Schuster, Mathieu and Arnaud, Nicolas and Monié, Patrick and Lihoreau, Fabrice and Likius, Andossa and Mackaye, Hassan Taïsso and Vignaud, Patrick and Brunet, Michel",
    title = "Cosmogenic nuclide dating of Sahelanthropus tchadensis and Australopithecus bahrelghazali: Mio-Pliocene hominids from Chad",
    year = "2008",
    journal = "Proceedings of the National Academy of Sciences",
    abstract = "Ages were determined at two hominid localities from the Chad Basin in the Djurab Desert (Northern Chad). In the Koro Toro fossiliferous area, KT 12 locality (16 degrees 00'N, 18 degrees 53'E) was the site of discovery of Australopithecus bahrelghazali (Abel) and in the Toros-Menalla fossiliferous area, TM 266 locality (16 degrees 15'N, 17 degrees 29'E) was the site of discovery of Sahelanthropus tchadensis (Toumaï). At both localities, the evolutive degree of the associated fossil mammal assemblages allowed a biochronological estimation of the hominid remains: early Pliocene (3-3.5 Ma) at KT 12 and late Miocene (approximately 7 Ma) at TM 266. Atmospheric (10)Be, a cosmogenic nuclide, was used to quasicontinuously date these sedimentary units. The authigenic (10)Be/(9)Be dating of a pelite relic within the sedimentary level containing Abel yields an age of 3.58 +/- 0.27 Ma that points to the contemporaneity of Australopithecus bahrelghazali (Abel) with Australopithecus afarensis (Lucy). The 28 (10)Be/(9)Be ages obtained within the anthracotheriid unit containing Toumaï bracket, by absolute dating, the age of Sahelanthropus tchadensis to lie between 6.8 and 7.2 Ma. This chronological constraint is an important cornerstone both for establishing the earliest stages of hominid evolution and for new calibrations of the molecular clock.",
    url = "https://doi.org/10.1073/pnas.0708015105",
    doi = "10.1073/pnas.0708015105",
    openalex = "W2033078106"
}

@book{doi1010079781402099809,
    author = "Delson, Eric and Fleagle, John G. and Grine, Frederick E. and Leakey, Richard E. and MacPhee, Ross D. E",
    title = "The First Humans – Origin and Early Evolution of the Genus Homo",
    year = "2009",
    booktitle = "Vertebrate paleobiology and paleoanthroplogy series/Vertebrate paleobiology and paleoanthropology series",
    url = "https://doi.org/10.1007/978-1-4020-9980-9",
    doi = "10.1007/978-1-4020-9980-9",
    openalex = "W2495077849",
    references = "doi101002ajpa20733, doi10100797814899503456, doi101016jjhevol200406002, doi101016s0047248477800262, doi101038242447a0, doi101038nature03822, doi101111j10963642200500165x, openalexw2020861622"
}

Hominid fossils predating the emergence of Australopithecus have been sparse and fragmentary. The evolution of our lineage after the last common ancestor we shared with chimpanzees has therefore remained unclear. Ardipithecus ramidus, recovered in ecologically and temporally resolved contexts in Ethiopia's Afar Rift, now illuminates earlier hominid paleobiology and aspects of extant African ape evolution. More than 110 specimens recovered from 4.4-million-year-old sediments include a partial skeleton with much of the skull, hands, feet, limbs, and pelvis. This hominid combined arboreal palmigrade clambering and careful climbing with a form of terrestrial bipedality more primitive than that of Australopithecus. Ar. ramidus had a reduced canine/premolar complex and a little-derived cranial morphology and consumed a predominantly C3 plant-based diet (plants using the C3 photosynthetic pathway). Its ecological habitat appears to have been largely woodland-focused. Ar. ramidus lacks any characters typical of suspension, vertical climbing, or knuckle-walking. Ar. ramidus indicates that despite the genetic similarities of living humans and chimpanzees, the ancestor we last shared probably differed substantially from any extant African ape. Hominids and extant African apes have each become highly specialized through very different evolutionary pathways. This evidence also illuminates the origins of orthogrady, bipedality, ecology, diet, and social behavior in earliest Hominidae and helps to define the basal hominid adaptation, thereby accentuating the derived nature of Australopithecus.

@article{doi101126science1175802,
    author = "White, Tim D. and Asfaw, Berhane and Beyene, Yonas and Haile‐Selassie, Yohannes and Lovejoy, C. Owen and Suwa, Gen and WoldeGabriel, Giday",
    title = "Ardipithecus ramidus and the Paleobiology of Early Hominids",
    year = "2009",
    journal = "Science",
    abstract = "Hominid fossils predating the emergence of Australopithecus have been sparse and fragmentary. The evolution of our lineage after the last common ancestor we shared with chimpanzees has therefore remained unclear. Ardipithecus ramidus, recovered in ecologically and temporally resolved contexts in Ethiopia's Afar Rift, now illuminates earlier hominid paleobiology and aspects of extant African ape evolution. More than 110 specimens recovered from 4.4-million-year-old sediments include a partial skeleton with much of the skull, hands, feet, limbs, and pelvis. This hominid combined arboreal palmigrade clambering and careful climbing with a form of terrestrial bipedality more primitive than that of Australopithecus. Ar. ramidus had a reduced canine/premolar complex and a little-derived cranial morphology and consumed a predominantly C3 plant-based diet (plants using the C3 photosynthetic pathway). Its ecological habitat appears to have been largely woodland-focused. Ar. ramidus lacks any characters typical of suspension, vertical climbing, or knuckle-walking. Ar. ramidus indicates that despite the genetic similarities of living humans and chimpanzees, the ancestor we last shared probably differed substantially from any extant African ape. Hominids and extant African apes have each become highly specialized through very different evolutionary pathways. This evidence also illuminates the origins of orthogrady, bipedality, ecology, diet, and social behavior in earliest Hominidae and helps to define the basal hominid adaptation, thereby accentuating the derived nature of Australopithecus.",
    url = "https://doi.org/10.1126/science.1175802",
    doi = "10.1126/science.1175802",
    openalex = "W1974259877",
    references = "doi10100215206505200093113aidevan230co2w, doi101002ajpa10019, doi101002ajpa10353, doi101002ajpa1330600302, doi101016jgaitpost200401001, doi101016s1251805001015294, doi10103835084063, doi101038371306a0, doi101038nature00879, doi101038nature04789, doi101038nature07891, doi101073pnas581142, doi101126science1107239, doi101126science1122666, doi101126science1158997, doi105962bhltitle24784"
}

@article{doi101016jepsl201103019,
    author = "Pickering, Robyn and Kramers, Jan D. and Hancox, Philip John and de Ruiter, Darryl J. and Woodhead, Jon",
    title = "Contemporary flowstone development links early hominin bearing cave deposits in South Africa",
    year = "2011",
    journal = "Earth and Planetary Science Letters",
    url = "https://doi.org/10.1016/j.epsl.2011.03.019",
    doi = "10.1016/j.epsl.2011.03.019",
    openalex = "W2071614585",
    references = "doi101038142377a0"
}

@article{doi101038nature11322,
    author = "Leakey, Meave G. and Spoor, Fred and Dean, M. Christopher and Feibel, Craig S. and Antón, Susan C. and Kiarie, Christopher and Leakey, Louise",
    title = "New fossils from Koobi Fora in northern Kenya confirm taxonomic diversity in early Homo",
    year = "2012",
    journal = "Nature",
    url = "https://doi.org/10.1038/nature11322",
    doi = "10.1038/nature11322",
    openalex = "W1994981345",
    references = "doi101038248653a0"
}

This pioneering volume summarizes the results of diverse research on Pleistocene environments and the cultural and biological evolution of man in Africa. The book includes chapters on Pleistocene stratigraphy and climatic changes throughout the African continent; on the ecology, biology and sociology of African primate and human populations. Contributors include: C. Arambourg, P. Biberson, W. W. Bishop, Geoffrey Bond, F. Bourlière, Karl W. Butzer, Desmond Clark, H. B. S. Cooke, Irven DeVore, John T. Emlen, A. T. Grove, J. de Heinzelin, J. Hiernaux, Clark Howell, L. S. B. Leakey, I. Liben, T. Monod, R. F. Moreau, R. A. pullan, J. T. Robinson, George B. Schaller, S. L. Washburn. Originally published in 1964.

@book{doi1043249781315017273,
    author = "Bourlière, François and Howell, Clark F.",
    title = "African Ecology and Human Evolution",
    year = "2013",
    abstract = "This pioneering volume summarizes the results of diverse research on Pleistocene environments and the cultural and biological evolution of man in Africa. The book includes chapters on Pleistocene stratigraphy and climatic changes throughout the African continent; on the ecology, biology and sociology of African primate and human populations. Contributors include: C. Arambourg, P. Biberson, W. W. Bishop, Geoffrey Bond, F. Bourlière, Karl W. Butzer, Desmond Clark, H. B. S. Cooke, Irven DeVore, John T. Emlen, A. T. Grove, J. de Heinzelin, J. Hiernaux, Clark Howell, L. S. B. Leakey, I. Liben, T. Monod, R. F. Moreau, R. A. pullan, J. T. Robinson, George B. Schaller, S. L. Washburn. Originally published in 1964.",
    url = "https://doi.org/10.4324/9781315017273",
    doi = "10.4324/9781315017273",
    openalex = "W2076861104"
}

@incollection{clarke2014hominids,
    author = "Clarke, Ronald J.",
    title = "Hominids, Earliest African",
    year = "2014",
    booktitle = "Encyclopedia of Global Archaeology",
    url = "https://doi.org/10.1007/978-1-4419-0465-2\_644",
    doi = "10.1007/978-1-4419-0465-2\_644",
    openalex = "W4214943676",
    pages = "3446-3449"
}

Integration of evidence over the past decade has revised understandings about the major adaptations underlying the origin and early evolution of the genus Homo. Many features associated with Homo sapiens, including our large linear bodies, elongated hind limbs, large energy-expensive brains, reduced sexual dimorphism, increased carnivory, and unique life history traits, were once thought to have evolved near the origin of the genus in response to heightened aridity and open habitats in Africa. However, recent analyses of fossil, archaeological, and environmental data indicate that such traits did not arise as a single package. Instead, some arose substantially earlier and some later than previously thought. From ~2.5 to 1.5 million years ago, three lineages of early Homo evolved in a context of habitat instability and fragmentation on seasonal, intergenerational, and evolutionary time scales. These contexts gave a selective advantage to traits, such as dietary flexibility and larger body size, that facilitated survival in shifting environments.

@article{doi101126science1236828,
    author = "Antón, Susan C. and Potts, Richard and Aiello, Leslie C.",
    title = "Evolution of early Homo: An integrated biological perspective",
    year = "2014",
    journal = "Science",
    abstract = "Integration of evidence over the past decade has revised understandings about the major adaptations underlying the origin and early evolution of the genus Homo. Many features associated with Homo sapiens, including our large linear bodies, elongated hind limbs, large energy-expensive brains, reduced sexual dimorphism, increased carnivory, and unique life history traits, were once thought to have evolved near the origin of the genus in response to heightened aridity and open habitats in Africa. However, recent analyses of fossil, archaeological, and environmental data indicate that such traits did not arise as a single package. Instead, some arose substantially earlier and some later than previously thought. From \textasciitilde 2.5 to 1.5 million years ago, three lineages of early Homo evolved in a context of habitat instability and fragmentation on seasonal, intergenerational, and evolutionary time scales. These contexts gave a selective advantage to traits, such as dietary flexibility and larger body size, that facilitated survival in shifting environments.",
    url = "https://doi.org/10.1126/science.1236828",
    doi = "10.1126/science.1236828",
    openalex = "W1964905272",
    references = "doi101002ajpa20733, doi101038202007a0, doi101038nature06134, doi101086667653, doi101126science1184944"
}

Our understanding of the origin of the genus Homo has been hampered by a limited fossil record in eastern Africa between 2.0 and 3.0 million years ago (Ma). Here we report the discovery of a partial hominin mandible with teeth from the Ledi-Geraru research area, Afar Regional State, Ethiopia, that establishes the presence of Homo at 2.80 to 2.75 Ma. This specimen combines primitive traits seen in early Australopithecus with derived morphology observed in later Homo, confirming that dentognathic departures from the australopith pattern occurred early in the Homo lineage. The Ledi-Geraru discovery has implications for hypotheses about the timing and place of origin of the genus Homo.

@article{doi101126scienceaaa1343,
    author = "Villmoare, Brian and Kimbel, William H. and Seyoum, Chalachew and Campisano, Christopher J. and DiMaggio, Erin and Rowan, John and Braun, David R. and Arrowsmith, J Ramón and Reed, Kaye E.",
    title = "Early Homo at 2.8 Ma from Ledi-Geraru, Afar, Ethiopia",
    year = "2015",
    journal = "Science",
    abstract = "Our understanding of the origin of the genus Homo has been hampered by a limited fossil record in eastern Africa between 2.0 and 3.0 million years ago (Ma). Here we report the discovery of a partial hominin mandible with teeth from the Ledi-Geraru research area, Afar Regional State, Ethiopia, that establishes the presence of Homo at 2.80 to 2.75 Ma. This specimen combines primitive traits seen in early Australopithecus with derived morphology observed in later Homo, confirming that dentognathic departures from the australopith pattern occurred early in the Homo lineage. The Ledi-Geraru discovery has implications for hypotheses about the timing and place of origin of the genus Homo.",
    url = "https://doi.org/10.1126/science.aaa1343",
    doi = "10.1126/science.aaa1343",
    openalex = "W2080240398",
    references = "doi101006jhev19960097, doi101007978146848854829, doi101016jjhevol200508012, doi101126science1184944"
}

This article is an attempt to reopen the problem of origins by examining critically some of the existing models of hominid differentiation, and to suggest a new one based on a fresh approach. Perhaps recognising this, adherents of the "predatory chimpanzee" model tend to situate the hominidpongid divergence in the late Pliocene, and regard all known fossils of basal Pleistocene Hominidae as representative of a short-lived transitional phase of imperfect hunting adaptation. While none of the previous models of hominid differentiation is without plausibility, none is very convincing. While there is little evidence for catastrophic desiccation in the tropics of the kind demanded by some models of hominid differentiation, there are indications that a trend towards seasonality persisted through the Tertiary, especially in Africa. A medium-sized Dryopithecus of the Miocene is a reasonable starting-point for hominid differentiation, and increased seasonality in the Middle-to-Upper Miocene and Lower Pliocene makes it likely that Phase I differentiation began at that time.

@incollection{doi104324978131512740848,
    author = "Jolly, Chris J.",
    title = "The Seed-Eaters: A New Model of Hominid Differentiation Based on a Baboon Analogy",
    year = "2017",
    abstract = {This article is an attempt to reopen the problem of origins by examining critically some of the existing models of hominid differentiation, and to suggest a new one based on a fresh approach. Perhaps recognising this, adherents of the "predatory chimpanzee" model tend to situate the hominidpongid divergence in the late Pliocene, and regard all known fossils of basal Pleistocene Hominidae as representative of a short-lived transitional phase of imperfect hunting adaptation. While none of the previous models of hominid differentiation is without plausibility, none is very convincing. While there is little evidence for catastrophic desiccation in the tropics of the kind demanded by some models of hominid differentiation, there are indications that a trend towards seasonality persisted through the Tertiary, especially in Africa. A medium-sized Dryopithecus of the Miocene is a reasonable starting-point for hominid differentiation, and increased seasonality in the Middle-to-Upper Miocene and Lower Pliocene makes it likely that Phase I differentiation began at that time.},
    url = "https://doi.org/10.4324/9781315127408-48",
    doi = "10.4324/9781315127408-48",
    openalex = "W2282070633"
}

@incollection{johanson2017a,
    author = "Johanson, D. C.",
    title = "A Systematic Assessment of Early African Hominids",
    year = "2017",
    booktitle = "Primate Evolution and Human Origins",
    url = "https://doi.org/10.4324/9781315127408-43",
    doi = "10.4324/9781315127408-43",
    openalex = "W4238044098",
    pages = "278-288"
}

@incollection{clarke2019hominids,
    author = "Clarke, Ronald J.",
    title = "Hominids, Earliest African",
    year = "2019",
    booktitle = "Encyclopedia of Global Archaeology",
    url = "https://doi.org/10.1007/978-3-319-51726-1\_644-2",
    doi = "10.1007/978-3-319-51726-1\_644-2",
    openalex = "W4245638351",
    pages = "1-5",
    references = "doi101038170405e0, doi10103835084063, doi101038nature00879, doi101038nature03392, doi101038nature03397, doi101073pnas0708015105, doi101093oxfordjournalsafrafa101747, doi105860choice430409, doi107208chicago97802260275240010001, openalexw52563376"
}

@article{doi10109701naj000051156004823dd,
    author = "Altaba, Cristian R.",
    title = "The conundrum of hominid systematics",
    year = "2019",
    journal = "Ludus vitalis: revista de filosofía de las ciencias de la vida = journal of philosophy of life sciences = revue de philosophie des sciences de la vie",
    url = "https://doi.org/10.1097/01.naj.0000511560.04823.dd",
    doi = "10.1097/01.naj.0000511560.04823.dd",
    openalex = "W28030398",
    references = "openalexw1533263862"
}

@incollection{clarke2020hominids,
    author = "Clarke, Ronald J.",
    title = "Hominids, Earliest African",
    year = "2020",
    booktitle = "Encyclopedia of Global Archaeology",
    url = "https://doi.org/10.1007/978-3-030-30018-0\_644",
    doi = "10.1007/978-3-030-30018-0\_644",
    openalex = "W4240747641",
    pages = "5244-5248",
    references = "doi101038170405e0, doi10103835084063, doi101038nature00879, doi101038nature03392, doi101038nature03397, doi101073pnas0708015105, doi101093oxfordjournalsafrafa101747, doi105860choice430409, doi107208chicago97802260275240010001, openalexw52563376"
}

@article{doi101007s00114020016969,
    author = "Brasil, Marianne F. and Monson, Tesla A. and Schmitt, Christopher A. and Hlusko, Leslea J.",
    title = "A genotype:phenotype approach to testing taxonomic hypotheses in hominids",
    year = "2020",
    journal = "Die Naturwissenschaften",
    url = "https://doi.org/10.1007/s00114-020-01696-9",
    doi = "10.1007/s00114-020-01696-9",
    openalex = "W3082948903",
    references = "doi105070p9351040776"
}

The phylogenetic position of Homo habilis is central to debates over the origin and early evolution of the genus Homo. A large portion of the species hypodigm consists of dental remains, but they have only been studied at the often worn enamel surface. We investigate the morphology of the H. habilis enamel-dentine junction (EDJ), which is preserved in cases of moderate tooth wear and known to carry a strong taxonomic signal. Geometric morphometrics is used to characterise dentine crown shape and size across the entire mandibular and maxillary tooth rows, compared with a broad comparative sample (n = 712). We find that EDJ morphology in H. habilis is for the most part remarkably primitive, supporting the hypothesis that the H. habilis hypodigm has more in common with Australopithecus than later Homo. Additionally, the chronologically younger specimen OH 16 displays a suite of derived features; its inclusion in H. habilis leads to excessive levels of variation.

@article{doi101038s41467023443759,
    author = "Davies, Thomas W. and Gunz, Philipp and Spoor, Fred and Alemseged, Zeresenay and Gidna, Agness and Hublin, Jean‐Jacques and Kimbel, William H. and Kullmer, Ottmar and Plummer, William P. and Zanolli, Clément and Skinner, Matthew M.",
    title = "Dental morphology in Homo habilis and its implications for the evolution of early Homo",
    year = "2024",
    journal = "Nature Communications",
    abstract = "The phylogenetic position of Homo habilis is central to debates over the origin and early evolution of the genus Homo. A large portion of the species hypodigm consists of dental remains, but they have only been studied at the often worn enamel surface. We investigate the morphology of the H. habilis enamel-dentine junction (EDJ), which is preserved in cases of moderate tooth wear and known to carry a strong taxonomic signal. Geometric morphometrics is used to characterise dentine crown shape and size across the entire mandibular and maxillary tooth rows, compared with a broad comparative sample (n = 712). We find that EDJ morphology in H. habilis is for the most part remarkably primitive, supporting the hypothesis that the H. habilis hypodigm has more in common with Australopithecus than later Homo. Additionally, the chronologically younger specimen OH 16 displays a suite of derived features; its inclusion in H. habilis leads to excessive levels of variation.",
    url = "https://doi.org/10.1038/s41467-023-44375-9",
    doi = "10.1038/s41467-023-44375-9",
    openalex = "W4390579467",
    references = "doi107203sjp27118090"
}