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1.
J Hum Evol ; 173: 103255, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36375243

RESUMO

Postcranial bones may provide valuable information about fossil taxa relating to their locomotor habits, manipulative abilities and body sizes. Distinctive features of the postcranial skeleton are sometimes noted in species diagnoses. Although numerous isolated postcranial fossils have become accepted by many workers as belonging to a particular species, it is worthwhile revisiting the evidence for each attribution before including them in comparative samples in relation to the descriptions of new fossils, functional analyses in relation to particular taxa, or in evolutionary contexts. Although some workers eschew the taxonomic attribution of postcranial fossils as being less important (or interesting) than interpreting their functional morphology, it is impossible to consider the evolution of functional anatomy in a taxonomic and phylogenetic vacuum. There are 21 widely recognized hominin taxa that have been described from sites in Africa dated from the Late Miocene to the Middle Pleistocene; postcranial elements have been attributed to 17 of these. The bones that have been thus assigned range from many parts of a skeleton to isolated elements. However, the extent to which postcranial material can be reliably attributed to a specific taxon varies considerably from site to site and species to species, and is often the subject of considerable debate. Here, we review the postcranial remains attributed to African hominin taxa from the Late Miocene to the Middle and Late Pleistocene and place these assignations into categories of reliability. The catalog of attributions presented here may serve as a guide for making taxonomic decisions in the future.


Assuntos
Hominidae , Humanos , Animais , Hominidae/anatomia & histologia , Filogenia , Reprodutibilidade dos Testes , Fósseis , Osso e Ossos/anatomia & histologia
2.
Proc Natl Acad Sci U S A ; 119(41): e2200689119, 2022 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-36191229

RESUMO

Evidence of how gestational parameters evolved is essential to understanding this fundamental stage of human life. Until now, these data seemed elusive given the skeletal bias of the fossil record. We demonstrate that dentition provides a window into the life of neonates. Teeth begin to form in utero and are intimately associated with gestational development. We measured the molar dentition for 608 catarrhine primates and collected data on prenatal growth rate (PGR) and endocranial volume (ECV) for 19 primate genera from the literature. We found that PGR and ECV are highly correlated (R2 = 0.93, P < 0.001). Additionally, we demonstrated that molar proportions are significantly correlated with PGR (P = 0.004) and log-transformed ECV (P = 0.001). From these correlations, we developed two methods for reconstructing PGR in the fossil record, one using ECV and one using molar proportions. Dental proportions reconstruct hominid ECV (R2 = 0.81, P < 0.001), a result that can be extrapolated to PGR. As teeth dominate fossil assemblages, our findings greatly expand our ability to investigate life history in the fossil record. Fossil ECVs and dental measurements from 13 hominid species both support significantly increasing PGR throughout the terminal Miocene and Plio-Pleistocene, reflecting known evolutionary changes. Together with pelvic and endocranial morphology, reconstructed PGRs indicate the need for increasing maternal energetics during pregnancy over the last 6 million years, reaching a human-like PGR (i.e., more similar to humans than to other extant apes) and ECV in later Homo less than 1 million years ago.


Assuntos
Evolução Biológica , Hominidae , Animais , Feminino , Fósseis , Hominidae/anatomia & histologia , Humanos , Recém-Nascido , Dente Molar , Gravidez
3.
J Hum Evol ; 173: 103265, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36306541

RESUMO

Fossil discoveries of early Australopithecus species from Woranso-Mille have played a significant role in improving our understanding of mid-Pliocene hominin evolution and diversity. Here, we describe two mandibles with dentitions, recovered from sediments immediately above a tuff radiometrically dated to 3.76 ± 0.02 Ma, and assess their taxonomic affinity. The two mandibles (MSD-VP-5/16 and MSD-VP-5/50) show morphological similarities with both Australopithecus anamensis and Australopithecus afarensis. Some of the unique features that distinguish Au. anamensis from Au. afarensis are present in the mandibles, which also share a few derived features with Au. afarensis. Their retention of more Kanapoi Au. anamensis-like traits, compared to the fewer derived features they share with Au. afarensis, and the presence of Au. anamensis at Woranso-Mille in 3.8-million-year-old deposits, lends support to their assignment to Au. anamensis. However, it is equally arguable that the few derived dentognathic features they share with Au. afarensis could be taxonomically more significant, making it difficult to conclusively assign these specimens to either species. Regardless of which species they are assigned to, the mosaic nature of the dentognathic morphology and geological age of the two mandibles lends further support to the hypothesized ancestor-descendant relationship between Au. anamensis and Au. afarensis. However, there is now limited fossil evidence indicating that these two species may have overlapped in time. Hence, the last appearance of Au. anamensis and first appearance of Au. afarensis are currently unknown. Recovery of Australopithecus fossils from 4.1 to 3.8 Ma is critical to further address the timing of these events.


Assuntos
Hominidae , Animais , Hominidae/anatomia & histologia , Etiópia , Fósseis , Mandíbula/anatomia & histologia , Geologia , Evolução Biológica
4.
J Hum Evol ; 171: 103239, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36095909

RESUMO

Previous research has suggested that magnitudes of integration may be distinct in the postcranium of hominoids when compared to other primate species. To test this hypothesis, we estimated and compared magnitudes of integration of eight postcranial bones from three-dimensional surface scans for 57 Hylobates lar, 58 Gorilla gorilla, 60 Pan troglodytes, 60 Homo sapiens, 60 Chlorocebus pygerythrus, and 60 Macaca fascicularis. We tested the hypotheses that 1) magnitudes of integration would be distinct in the postcranium of hominoids compared to cercopithecoids, with the explicit prediction that magnitudes of integration would be lower in hominoids than in cercopithecoids, and 2) girdle elements (scapula, os coxa) would have lower magnitudes of integration across all taxa. Integration was quantified using the integration coefficient of variation from interlandmark distances reflecting anatomical and developmental modules defined according to a priori criteria. A resampling protocol was employed to generate distributions of integration values that were then compared statistically using Mann-Whitney U tests with Bonferroni adjustment. Support for hypothesis 1 was mixed: with the exception of Gorilla, hominoid taxa were less integrated than the cercopithecoids for all anatomical modules. However, Homo, Gorilla, and, to a lesser extent, Pan showed higher integration than Hylobates and the cercopithecoids for homologous limb elements, with magnitudes of integration for both modules being lowest for Hylobates. These results generally support the hypothesis of distinct patterns of magnitudes of integration in the hominoid postcranium. The high integration of Gorilla may be explained by the effects of overall body size. The results supported the predictions of the second hypothesis. Regardless of taxon, the os coxa and scapula were generally the least integrated skeletal elements, while the femur and radius were the most integrated. The lower integration of the girdle elements suggests that the geometric complexities of particular elements may significantly influence study outcomes.


Assuntos
Hominidae , Hylobates , Animais , Chlorocebus aethiops , Gorilla gorilla , Hominidae/anatomia & histologia , Hylobates/anatomia & histologia , Pan troglodytes/anatomia & histologia , Primatas , Escápula
5.
Nat Ecol Evol ; 6(10): 1573-1585, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36064759

RESUMO

Previous scientific consensus saw human evolution as defined by adaptive differences (behavioural and/or biological) and the emergence of Homo sapiens as the ultimate replacement of non-modern groups by a modern, adaptively more competitive group. However, recent research has shown that the process underlying our origins was considerably more complex. While archaeological and fossil evidence suggests that behavioural complexity may not be confined to the modern human lineage, recent palaeogenomic work shows that gene flow between distinct lineages (for example, Neanderthals, Denisovans, early H. sapiens) occurred repeatedly in the late Pleistocene, probably contributing elements to our genetic make-up that might have been crucial to our success as a diverse, adaptable species. Following these advances, the prevailing human origins model has shifted from one of near-complete replacement to a more nuanced view of partial replacement with considerable reticulation. Here we provide a brief introduction to the current genetic evidence for hybridization among hominins, its prevalence in, and effects on, comparative mammal groups, and especially how it manifests in the skull. We then explore the degree to which cranial variation seen in the fossil record of late Pleistocene hominins from Western Eurasia corresponds with our current genetic and comparative data. We are especially interested in understanding the degree to which skeletal data can reflect admixture. Our findings indicate some correspondence between these different lines of evidence, flag individual fossils as possibly admixed, and suggest that different cranial regions may preserve hybridization signals differentially. We urge further studies of the phenotype to expand our ability to detect the ways in which migration, interaction and genetic exchange have shaped the human past, beyond what is currently visible with the lens of ancient DNA.


Assuntos
Hominidae , Homem de Neandertal , Animais , DNA Antigo , Fósseis , Hominidae/anatomia & histologia , Hominidae/genética , Humanos , Hibridização Genética , Mamíferos/genética , Homem de Neandertal/genética
6.
PLoS One ; 17(9): e0274170, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36067159

RESUMO

The fork cell and von Economo neuron, which are found in the insular cortex and/or the anterior cingulate cortex, are defined by their unique morphologies. Their shapes are not pyramidal; the fork cell has two primary apical dendrites and the von Economo neurons are spindle-shaped (bipolar). Presence of such neurons are reported only in the higher animals, especially in human and great ape, indicating that they are specific for most evolved species. Although it is likely that these neurons are involved in higher brain function, lack of results with experimental animals makes further investigation difficult. We here ask whether equivalent neurons exist in the mouse insular cortex. In human, Fezf2 has been reported to be highly expressed in these morphologically distinctive neurons and thus, we examined the detailed morphology of Fezf2-positive neurons in the mouse brain. Although von Economo-like neurons were not identified, Fezf2-positive fork cell-like neurons with two characteristic apical dendrites, were discovered. Examination with electron microscope indicated that these neurons did not embrace capillaries, rather they held another cell. We here term such neurons as holding neurons. We further observed several molecules, including neuromedin B (NMB) and gastrin releasing peptide (GRP) that are known to be localized in the fork cells and/or von Economo cells in human, were localized in the mouse insular cortex. Based on these observations, it is likely that an equivalent of the fork cell is present in the mouse.


Assuntos
Córtex Cerebral , Hominidae , Animais , Córtex Cerebral/fisiologia , Giro do Cíngulo , Hominidae/anatomia & histologia , Humanos , Córtex Insular , Camundongos , Neurônios/fisiologia
7.
J Hum Evol ; 172: 103256, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36156434

RESUMO

Previous research has found that hominoids have stronger modularity between limb elements than other anthropoids, suggesting that there is less constraint on morphological diversification (e.g., limb proportions) in hominoids in terms of evolutionary independence. However, degrees of modularity in the axial skeleton have not been investigated across a broad range of anthropoid taxa. Thus, it is unknown whether hominoids also have stronger modularity in the axial skeleton than other anthropoids, which has implications for the evolution of diverse torso morphologies in Miocene apes as well as the evolution of novel characteristics in the skull and vertebrae of fossil hominins. In this study, 12 anthropoid genera were sampled to examine degrees of modularity between axial skeletal elements (i.e., cranium, mandible, vertebrae, and sacrum). Covariance ratio coefficients were calculated using variance/covariance matrices of interlandmark distances for each axial skeletal element to evaluate degrees of modularity. The results showed that Alouatta, Hylobates, Gorilla, Pan, and Homo showed generally stronger modularity than other anthropoid taxa when considering all axial skeletal elements. When only considering the vertebral elements (i.e., vertebrae and sacrum), Alouatta, Hylobates, Gorilla, and Pan showed generally stronger modularity than other anthropoid taxa. Humans showed stronger modularity between the skull and vertebrae than other hominoids. Thus, the evolution of novel characteristics in the skull and vertebral column may have been less constrained in fossil hominins due to the dissociation of trait covariation between axial skeletal elements in hominoid ancestors, thus fostering more evolutionary independence between the skull and vertebral column.


Assuntos
Alouatta , Hominidae , Humanos , Animais , Hylobates/anatomia & histologia , Gorilla gorilla , Evolução Biológica , Hominidae/anatomia & histologia , Fósseis , Haplorrinos/anatomia & histologia
8.
J Hum Evol ; 172: 103253, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36162354

RESUMO

The early Middle Pleistocene human material from Boxgrove (West Sussex, UK) consists of a partial left tibia and two lower incisors from a separate adult individual. These remains derive from deposits assigned to the MIS 13 interglacial at about 480 ka and have been referred to as Homo cf. heidelbergensis. The much larger skeletal sample from the Sima de los Huesos (Atapuerca, Spain) is dated to the succeeding MIS 12, at about 430 ka. This fossil material has previously been assigned to Homo heidelbergensis but is now placed within the Neanderthal clade. Because of the scarcity of human remains from the Middle Pleistocene and their morphological variability, this study assessed whether the Boxgrove specimens fit within the morphological variability of the homogeneous Sima de los Huesos population. Based on morphometric analyses performed against 22 lower incisors from Sima de los Huesos and published material, the data from the Boxgrove incisors place them comfortably within the range of Sima de los Huesos. Both assemblages present robust incisors distinct from the overall small recent Homo sapiens incisors, and Boxgrove also aligns closely with Homo neanderthalensis and some other European Middle Pleistocene hominins. Following morphological and cross-sectional analyses of the Boxgrove tibia compared to seven adult Sima de los Huesos specimens and a set of comparative tibiae, Boxgrove is shown to be similar to Sima de los Huesos and Neanderthals in having thick cortices and bone walls, but in contrast resembles modern humans in having a straight anterior tibial crest and a suggestion of a lateral concavity. Based on the patterns observed, there is no justification for assigning the Boxgrove and Sima de los Huesos incisors to distinct paleodemes, but the tibial data show greater contrasts and suggest that all three of these samples are unlikely to represent the same paleodeme.


Assuntos
Hominidae , Homem de Neandertal , Animais , Adulto , Humanos , Fósseis , Estudos Transversais , Hominidae/anatomia & histologia , Homem de Neandertal/anatomia & histologia , Tíbia/anatomia & histologia , Espanha
9.
J Hum Evol ; 172: 103252, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36162353

RESUMO

Late Pleistocene hominin postcranial specimens from Southeast Asia are relatively rare. Here we describe and place into temporal and geographic context two partial femora from the site of Trinil, Indonesia, which are dated stratigraphically and via Uranium-series direct dating to ca. 37-32 ka. The specimens, designated Trinil 9 and 10, include most of the diaphysis, with Trinil 9 being much better preserved. Microcomputed tomography is used to determine cross-sectional diaphyseal properties, with an emphasis on midshaft anteroposterior to mediolateral bending rigidity (Ix/Iy), which has been shown to relate to both body shape and activity level in modern humans. The body mass of Trinil 9 is estimated from cortical area and reconstructed length using new equations based on a Pleistocene reference sample. Comparisons are carried out with a large sample of Pleistocene and Holocene East Asian, African, and European/West Asian femora. Our results show that Trinil 9 has a high Ix/Iy ratio, most consistent with a relatively narrow-bodied male from a mobile hunting-gathering population. It has an estimated body mass of 55.4 kg and a stature of 156 cm, which are small relative to Late Pleistocene males worldwide, but larger than the penecontemporaneous Deep Skull femur from Niah Cave, Malaysia, which is very likely female. This suggests the presence of small-bodied active hunter-gatherers in Southeast Asia during the later Late Pleistocene. Trinil 9 also contrasts strongly in morphology with earlier partial femora from Trinil dating to the late Early-early Middle Pleistocene (Femora II-V), and to a lesser extent with the well-known complete Femur I, most likely dating to the terminal Middle-early Late Pleistocene. Temporal changes in morphology among femoral specimens from Trinil parallel those observed in Homo throughout the Old World during the Pleistocene and document these differences within a single site.


Assuntos
Hominidae , Urânio , Animais , Humanos , Masculino , Feminino , Fósseis , Indonésia , Microtomografia por Raio-X , Estudos Transversais , Hominidae/anatomia & histologia , Tamanho Corporal , Fêmur/anatomia & histologia
10.
J Hum Evol ; 170: 103234, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36001899

RESUMO

Understanding the biogeography and evolution of Miocene catarrhines relies on accurate specimen provenience. It has long been speculated that some catarrhine specimens among the early collections from Miocene sites in Kenya have incorrect provenience data. The provenience of one of these, the holotype of Equatorius africanus (NHM M16649), was previously revised based on x-ray fluorescence spectroscopy. Here we use nondestructive portable x-ray fluorescence spectroscopy to test the provenience of additional catarrhine specimens that, based on morphology and/or incomplete provenience information, were identified as possibly having been collected at a different site from that recorded at museum accession. We test the hypotheses that two specimens purportedly from the Early Miocene site of Rusinga (KNM-RU 1681 and KNM-RU 1999) are instead from Maboko, three specimens purportedly from the Middle Miocene site of Fort Ternan (KNM-FT 8, KNM-FT 41, and KNM-FT 3318) are instead from Songhor, and one specimen accessioned as being from Songhor (KNM-SO 5352) is from that site. Elemental data reveal that two of the specimens (KNM-FT 3318 and KNM-RU 1681) are likely to have been collected at sites other than their museum-accessioned provenience, while two others (KNM-RU 1999, and KNM-FT 41) were confirmed to have correct provenience. Results for both KNM-FT 8 and KNM-SO 5352, while somewhat equivocal, are best interpreted as supporting their accessioned provenience. Our results have implications for the distribution of certain catarrhine species during the Miocene in Kenya. Confirmation of the provenience of the specimens also facilitates taxonomic attribution, and resulted in additions to the morphological characterizations of some species. The protocol presented here has potential for wider application to assessing questions of provenience for fossils from other locations and periods.


Assuntos
Fósseis , Hominidae , Animais , Cercopithecidae , Hominidae/anatomia & histologia , Quênia , Primatas , Espectrometria por Raios X
11.
J Hum Evol ; 170: 103233, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36030625

RESUMO

Pongo fossils with precise absolute age brackets are rare, limiting our understanding of their taxonomy and spatiotemporal distribution in southern China during the Late Pleistocene. Twenty-four isolated teeth of fossil orangutans were recently discovered during excavations at Yicun Cave in Guangxi Zhuang Autonomous Region, southern China. Here, we dated the fossil-bearing layer using Uranium-series dating of the associated flowstone and soda straw stalactites. Our results date the Yicun orangutan fossils to between 66 ± 0.32 ka and 57 ± 0.26 ka; thus, these fossils currently represent the last appearance datum of Pongo in southern China. We further conducted a detailed morphological comparison of the Yicun fossil teeth with large samples of fossil (n = 2454) and extant (n = 441) orangutans from mainland and island Southeast Asia to determine their taxonomic position. Compared to other fossil and extant orangutan samples, the Yicun Pongo assemblage has larger teeth and displays greater variation in occlusal structure. Based on the high frequency of cingular remnants and light to moderate enamel wrinkling of the molars, we assigned the Yicun fossils to Pongo weidenreichi, a species that was widespread in southern China throughout the Pleistocene. Lastly, we used published stable carbon isotope data of Early to Late Pleistocene mammalian fossil teeth from mainland Southeast Asia to reconstruct changes in the paleoenvironment and to interpret dental size variation of Pongo assemblages in a broader temporal and environmental context. The carbon isotope data show that dental size reduction in Pongo is associated with environmental changes. These morphological changes in Pongo appear to coincide with the expansion of savannah biomes and the contraction of forest habitats from the Middle Pleistocene onward. The variation in dental size of forest-dwelling Pongo in mainland Southeast Asia may have resulted from habitat differentiation during the Pleistocene.


Assuntos
Hominidae , Dente , Animais , Isótopos de Carbono , China , Fósseis , Hominidae/anatomia & histologia , Mamíferos , Pongo , Pongo pygmaeus
12.
Sci Rep ; 12(1): 13956, 2022 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-35977986

RESUMO

Most fossil hominin species are sampled with spatial, temporal or anatomical biases that can hinder assessments of their paleodiversity, and may not yield genuine evolutionary signals. We use new fossils from the Kromdraai (Unit P) and Drimolen sites (South Africa) to provide insights into the paleodiversity of the Lower Pleistocene robust australopith, Paranthropus robustus. Our focus is the morphology of the temporal bone and the relationships between size and shape (allometry) of the semi-circular canals (SCC), an aspect that has not yet been investigated among southern African australopiths. We find significant size and shape SCC differences between P. robustus from Kromdraai, Drimolen and Swartkrans. This site-related variation is consistent with other differences observed on the temporal bone. P. robustus from Kromdraai Unit P is distinctive because of its smaller temporal bone and SCC, and its proportionally less developed posterior SCC, independently of age and sex. We emphasize the importance of allometry to interpret paleodiversity in P. robustus as either the consequence of differences in body size, or as yet unknown factors. Some features of the inner ear of P. robustus represent directional selection soon after its origin, whereas the size and shape variations described here may result from evolutionary changes.


Assuntos
Orelha Interna , Hominidae , Animais , Evolução Biológica , Fósseis , Hominidae/anatomia & histologia , África do Sul
13.
Proc Natl Acad Sci U S A ; 119(35): e2123366119, 2022 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-35994633

RESUMO

Variability in resource availability is hypothesized to be a significant driver of primate adaptation and evolution, but most paleoclimate proxies cannot recover environmental seasonality on the scale of an individual lifespan. Oxygen isotope compositions (δ18O values) sampled at high spatial resolution in the dentitions of modern African primates (n = 2,352 near weekly measurements from 26 teeth) track concurrent seasonal precipitation, regional climatic patterns, discrete meteorological events, and niche partitioning. We leverage these data to contextualize the first δ18O values of two 17 Ma Afropithecus turkanensis individuals from Kalodirr, Kenya, from which we infer variably bimodal wet seasons, supported by rainfall reconstructions in a global Earth system model. Afropithecus' δ18O fluctuations are intermediate in magnitude between those measured at high resolution in baboons (Papio spp.) living across a gradient of aridity and modern forest-dwelling chimpanzees (Pan troglodytes verus). This large-bodied Miocene ape consumed seasonally variable food and water sources enriched in 18O compared to contemporaneous terrestrial fauna (n = 66 fossil specimens). Reliance on fallback foods during documented dry seasons potentially contributed to novel dental features long considered adaptations to hard-object feeding. Developmentally informed microsampling recovers greater ecological complexity than conventional isotope sampling; the two Miocene apes (n = 248 near weekly measurements) evince as great a range of seasonal δ18O variation as more time-averaged bulk measurements from 101 eastern African Plio-Pleistocene hominins and 42 papionins spanning 4 million y. These results reveal unprecedented environmental histories in primate teeth and suggest a framework for evaluating climate change and primate paleoecology throughout the Cenozoic.


Assuntos
Evolução Biológica , Mudança Climática , Fósseis , Isótopos de Oxigênio , Pan troglodytes , Dente , África , Animais , Guiné Equatorial , Fósseis/anatomia & histologia , História do Século XXI , Hominidae/anatomia & histologia , Quênia , Isótopos de Oxigênio/análise , Pan troglodytes/anatomia & histologia , Papio/anatomia & histologia , Primatas/anatomia & histologia , Dente/anatomia & histologia , Dente/química
14.
J Hum Evol ; 170: 103231, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35940157

RESUMO

The calculation of morphological integration across living apes and humans may provide important insights into the potential influence of integration on evolutionary trajectories in the hominid lineage. Here, we quantify magnitudes of morphological integration among and within elements of the midfoot in great apes and humans to examine the link between locomotor differences and trait covariance. We test the hypothesis that the medial elements of the great ape foot are less morphologically integrated with one another compared to humans based on their abducted halluces, and aim to determine how adaptations for midfoot mobility/stiffness and locomotor specialization influence magnitudes of morphological integration. The study sample is composed of all cuneiforms, the navicular, the cuboid, and metatarsals 1-5 of Homo sapiens (n = 80), Pan troglodytes (n = 63), Gorilla gorilla (n = 39), and Pongo sp. (n = 41). Morphological integration was quantified using the integration coefficient of variation of interlandmark distances organized into sets of a priori-defined modules. Magnitudes of integration across these modules were then compared against sets of random traits from the whole midfoot. Results show that all nonhuman apes have less integrated medial elements, whereas humans have highly integrated medial elements, suggesting a link between hallucal abduction and reduced levels of morphological integration. However, we find considerable variation in magnitudes of morphological integration across metatarsals 2-5, the intermediate and lateral cuneiform, the cuboid, and navicular, emphasizing the influence of functional and nonfunctional factors in magnitudes of integration. Lastly, we find that humans and orangutans show the lowest overall magnitudes of integration in the midfoot, which may be related to their highly specialized functions, and suggest a link between strong diversifying selection and reduced magnitudes of morphological integration.


Assuntos
Hominidae , Animais , Pé/anatomia & histologia , Gorilla gorilla/anatomia & histologia , Hominidae/anatomia & histologia , Humanos , Pan troglodytes/anatomia & histologia , Pongo , Pongo pygmaeus
15.
Nature ; 609(7925): 94-100, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36002567

RESUMO

Bipedal locomotion is one of the key adaptations that define the hominin clade. Evidence of bipedalism is known from postcranial remains of late Miocene hominins as early as 6 million years ago (Ma) in eastern Africa1-4. Bipedality of Sahelanthropus tchadensis was hitherto inferred about 7 Ma in central Africa (Chad) based on cranial evidence5-7. Here we present postcranial evidence of the locomotor behaviour of S. tchadensis, with new insights into bipedalism at the early stage of hominin evolutionary history. The original material was discovered at locality TM 266 of the Toros-Ménalla fossiliferous area and consists of one left femur and two, right and left, ulnae. The morphology of the femur is most parsimonious with habitual bipedality, and the ulnae preserve evidence of substantial arboreal behaviour. Taken together, these findings suggest that hominins were already bipeds at around 7 Ma but also suggest that arboreal clambering was probably a significant part of their locomotor repertoire.


Assuntos
Evolução Biológica , Marcha , Hominidae , Crânio , Animais , Chade , Fósseis , Hominidae/anatomia & histologia , Hominidae/fisiologia , Crânio/anatomia & histologia , Árvores
16.
Sci Adv ; 8(33): eabq4884, 2022 08 19.
Artigo em Inglês | MEDLINE | ID: mdl-35977020

RESUMO

Evolutionary responses to selection for bipedalism and childbirth have shaped the human pelvis, a structure that differs substantially from that in apes. Morphology related to these factors is present by birth, yet the developmental-genetic mechanisms governing pelvic shape remain largely unknown. Here, we pinpoint and characterize a key gestational window when human-specific pelvic morphology becomes recognizable, as the ilium and the entire pelvis acquire traits essential for human walking and birth. We next use functional genomics to molecularly characterize chondrocytes from different pelvic subelements during this window to reveal their developmental-genetic architectures. We then find notable evidence of ancient selection and genetic constraint on regulatory sequences involved in ilium expansion and growth, findings complemented by our phenotypic analyses showing that variation in iliac traits is reduced in humans compared to African apes. Our datasets provide important resources for musculoskeletal biology and begin to elucidate developmental mechanisms that shape human-specific morphology.


Assuntos
Hominidae , Pelve , Animais , Evolução Biológica , Feminino , Hominidae/anatomia & histologia , Humanos , Parto , Pelve/anatomia & histologia , Gravidez , Seleção Genética
17.
J Hum Evol ; 168: 103212, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35688108

RESUMO

The fossil hominin individual from Gongwangling of Lantian, Central China, represents one of the earliest members attributed to Homo erectus in East Asia. Recent paleomagnetic analyses have yielded an age of 1.63 Ma for the Gongwangling hominin. The fossils from this site are critical to characterize the morphological features of early hominins in East Asia and to understand their relationships with other earlier and later members of the genus Homo. However, most morphological details of the Gongwangling cranium were obliterated due to postmortem erosion and deformation. Here we used high-resolution microcomputed tomography and three-dimensional virtual imaging techniques to extract the teeth and reconstruct the worn/damaged areas, describe the external morphology, measure crown diameters, record nonmetric traits of the crown and root, and investigate the shape of the enamel-dentine junction using geometric morphometrics. We compared the data obtained from the six teeth of the Gongwangling hominin with African early Homo, African and Georgian Homo erectus s.l., Asian Homo erectus, Homo antecessor, pre-Neanderthals, Neanderthals, and modern humans. Our results show that the Gongwangling specimens display affinities with other specimens attributed to H. erectus s.l. The highly divergent and noncoalesced three-root system in the Gongwangling specimens is comparable to that in the Early Pleistocene members of H. erectus s.l., and differs from Middle Pleistocene representatives of the species. The enamel-dentine junction shape of the Gongwangling molars prefigures the Asian H. erectus pattern later found in East Asian Middle Pleistocene H. erectus. The morphological comparisons between East Asian Early Pleistocene (e.g., Gongwangling, Meipu, and Quyuan River Mouth) and Middle Pleistocene H. erectus (e.g., Zhoukoudian, Hexian, and Yiyuan) suggest a potential temporal trend within this species in East Asia.


Assuntos
Hominidae , Homem de Neandertal , Animais , China , Fósseis , Hominidae/anatomia & histologia , Humanos , Microtomografia por Raio-X
18.
J Hum Evol ; 169: 103221, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35772227

RESUMO

Within the primate order, the morphology of the shoulder girdle is immensely variable and has been shown to reflect the functional demands of the upper limb. The observed morphological variation among extant primate taxa consequently has been hypothesized to be driven by selection for different functional demands. Evolutionary analyses of the shoulder girdle often assess this anatomical region, and its traits, individually, therefore implicitly assuming independent evolution of the shoulder girdle. However, the primate shoulder girdle has developmental and functional covariances with the basicranium and pelvic girdle that have been shown to potentially influence its evolution. It is unknown whether these relationships are similar or even present across primate taxa, and how they may affect morphological variation among primates. This study evaluates the strength of covariance and evolutionary potential across four anatomical regions: shoulder girdle, basicranium, pelvis, and distal humerus. Measures of morphological integration and evolutionary potential (conditioned covariance and evolutionary flexibility) are assessed across eight anthropoid primate taxa. Results demonstrate a consistent pattern of morphological constraint within paired anatomical regions across primates. Differences in evolutionary flexibility are observed among primate genera, with humans having the highest evolutionary potential overall. This pattern does not follow functional differences, but rather a separation between monkeys and apes. Therefore, evolutionary hypotheses of primate shoulder girdle morphological variation that evaluate functional demands alone may not account for the effect of these relationships. Collectively, our findings suggest differences in genetic covariance among anatomical regions may have contributed to the observable morphological variation among taxa.


Assuntos
Hominidae , Ombro , Animais , Braço , Evolução Biológica , Hominidae/anatomia & histologia , Humanos , Pelve , Primatas/anatomia & histologia , Primatas/genética , Ombro/anatomia & histologia , Base do Crânio/anatomia & histologia
19.
J Morphol ; 283(7): 932-944, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35510698

RESUMO

Limited research on the gross anatomy of the blood vessels has been conducted on hylobatids, or lesser apes, so far. Here, we present a detailed study of the arteries of siamangs (Symphalangus) and compare our findings with data compiled from our previous studies as well as from the literature about other hylobatids, greater apes, and humans. In particular, a three-dimensional full-body computed tomography data set of a siamang neonate was analyzed in detail for this study, with notable findings in the head and neck, thorax, upper limb, abdomen and pelvis, and lower limb. Of the 62 arteries that we studied in detail, a total of 20 arteries that have never been described in detail in hylobatids are reported in this study. Key similarities to other apes differing from humans include the existence of a humeral common circumflex trunk and the origination of the dorsalis pedis from the posterior tibial artery or saphenous artery instead of the anterior tibial artery. Similarities to humans differing from other apes include the separation of the lingual and facial arteries and the origination of the profunda brachii from the brachial artery instead of the axillary artery. Our research and broader comparisons, therefore, contribute to knowledge about the soft tissues of hylobatids, other apes, and primates in general and facilitate a better understanding of the anatomical evolution and key differences and similarities among these taxa.


Assuntos
Hominidae , Hylobatidae , Sistema Musculoesquelético , Animais , Artérias/diagnóstico por imagem , Hominidae/anatomia & histologia , Humanos , Sistema Musculoesquelético/diagnóstico por imagem , Primatas
20.
Sci Rep ; 12(1): 8841, 2022 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-35614148

RESUMO

North Africa is a key area for understanding hominin population movements and the expansion of our species. It is home to the earliest currently known Homo sapiens (Jebel Irhoud) and several late Middle Stone Age (MSA) fossils, notably Kébibat, Contrebandiers 1, Dar-es-Soltane II H5 and El Harhoura. Mostly referred to as "Aterian" they fill a gap in the North African fossil record between Jebel Irhoud and Iberomaurusians. We explore morphological continuity in this region by quantifying mandibular shape using 3D (semi)landmark geometric morphometric methods in a comparative framework of late Early and Middle Pleistocene hominins (n = 15), Neanderthals (n = 27) and H. sapiens (n = 145). We discovered a set of mixed features among late MSA fossils that is in line with an accretion of modern traits through time and an ongoing masticatory gracilization process. In Northern Africa, Aterians display similarities to Iberomaurusians and recent humans in the area as well as to the Tighenif and Thomas Quarry hominins, suggesting a greater time depth for regional continuity than previously assumed. The evidence we lay out for a long-term succession of hominins and humans emphasizes North Africa's role as source area of the earliest H. sapiens.


Assuntos
Hominidae , Homem de Neandertal , África do Norte , Animais , Evolução Biológica , Fósseis , Hominidae/anatomia & histologia , Humanos , Mandíbula/anatomia & histologia , Homem de Neandertal/anatomia & histologia
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