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1.
J Hum Evol ; 157: 103032, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34233242

RESUMO

Pliopithecoids are a diverse group of Miocene catarrhine primates from Eurasia. Their positional behavior is still unknown, and many species are known exclusively from dentognathic remains. Here, we describe a proximal radius (IPS66267) from the late Miocene of Castell de Barberà (Vallès-Penedès Basin, NE Iberian Peninsula) that represents the first postcranial specimen of the pliopithecoid Barberapithecus huerzeleri. A body mass estimate based on the radius is compared with dental estimates, and its morphology is compared with that of extant and fossil anthropoids by qualitative means as well as by landmark-based three-dimensional geometric morphometrics. The estimated body mass of ∼5 kg for IPS66267 closely matches the dental estimates for the (female) holotype, thereby discounting an alternative attribution to the large-bodied hominoid recorded at Castell de Barberà. In multiple features (oval and moderately tilted head with a pronounced lateral lip and a restricted articular area for the capitulum; proximodistally expanded proximal radioulnar joint; and short, robust, and anteroposteriorly compressed neck), the specimen differs from hominoids and resembles instead extant nonateline monkeys and stem catarrhines. The results of the morphometric analysis further indicate that the Barberapithecus proximal radius shows closer similarities with nonsuspensory arboreal cercopithecoids and the dendropithecid Simiolus. From a locomotor viewpoint, the radius of Barberapithecus lacks most of the features functionally related to climbing and/or suspensory behaviors and displays instead a proximal radioulnar joint that would have been particularly stable under pronation. On the other hand, the Barberapithecus radius differs from other stem catarrhines in the less anteroposteriorly compressed and less tilted radial head with a deeper capitular fovea, suggesting a somewhat enhanced mobility at the elbow joint. We conclude that pronograde arboreal quadrupedalism was the main component of the locomotor repertoire of Barberapithecus but that, similar to other crouzeliids, it might have displayed better climbing abilities than pliopithecids.


Assuntos
Catarrinos/anatomia & histologia , Fósseis , Locomoção , Rádio (Anatomia)/anatomia & histologia , Animais , Feminino , Masculino
2.
J Hum Evol ; 156: 102998, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34020295

RESUMO

The evolution of novel vertebral morphologies observed in humans and other extant hominoids may be related to changes in the magnitudes and/or patterns of covariation among traits. To examine this, we tested magnitudes of integration in the vertebral column of cercopithecoids and hominoids, including humans. Three-dimensional surface scans of 14 vertebral elements from 30 Cercopithecus, 32 Chlorocebus, 39 Macaca, 45 Hylobates, 31 Pan, and 86 Homo specimens were used. A resampling method was used to generate distributions of integration coefficient of variation scores for vertebral elements individually using interlandmark distances. Interspecific comparisons of mean integration coefficient of variation were conducted using Mann-Whitney U tests with Bonferroni adjustment. The results showed that hominoids generally had lower mean integration coefficient of variation than cercopithecoids. In addition, humans showed lower mean integration coefficient of variation than other hominoids in their last thoracic and lumbar vertebrae. Cercopithecoids and Hylobates showed relatively lower mean integration coefficient of variation in cervical vertebrae than in thoracolumbar vertebrae. Pan and Homo showed relatively lower mean integration coefficient of variation in the last thoracic and lumbar vertebrae in the thoracolumbar region, except for the L1 of Pan. The results suggest fewer integration-mediated constraints on the evolution of vertebral morphology in hominoids when compared with cercopithecoids. The weaker magnitudes of integration in lumbar vertebrae in humans when compared with chimpanzees likewise suggest fewer constraints on the evolution of novel lumbar vertebrae morphology in humans.


Assuntos
Evolução Biológica , Catarrinos/anatomia & histologia , Vértebras Lombares , Vértebras Torácicas , Animais , Humanos
3.
Proc Natl Acad Sci U S A ; 118(13)2021 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-33771926

RESUMO

Infection with human and simian immunodeficiency viruses (HIV/SIV) requires binding of the viral envelope glycoprotein (Env) to the host protein CD4 on the surface of immune cells. Although invariant in humans, the Env binding domain of the chimpanzee CD4 is highly polymorphic, with nine coding variants circulating in wild populations. Here, we show that within-species CD4 diversity is not unique to chimpanzees but found in many African primate species. Characterizing the outermost (D1) domain of the CD4 protein in over 500 monkeys and apes, we found polymorphic residues in 24 of 29 primate species, with as many as 11 different coding variants identified within a single species. D1 domain amino acid replacements affected SIV Env-mediated cell entry in a single-round infection assay, restricting infection in a strain- and allele-specific fashion. Several identical CD4 polymorphisms, including the addition of N-linked glycosylation sites, were found in primate species from different genera, providing striking examples of parallel evolution. Moreover, seven different guenons (Cercopithecus spp.) shared multiple distinct D1 domain variants, pointing to long-term trans-specific polymorphism. These data indicate that the HIV/SIV Env binding region of the primate CD4 protein is highly variable, both within and between species, and suggest that this diversity has been maintained by balancing selection for millions of years, at least in part to confer protection against primate lentiviruses. Although long-term SIV-infected species have evolved specific mechanisms to avoid disease progression, primate lentiviruses are intrinsically pathogenic and have left their mark on the host genome.


Assuntos
Síndrome de Imunodeficiência Adquirida/genética , Antígenos CD4/genética , Catarrinos/genética , Catarrinos/virologia , Variação Genética , HIV , Síndrome de Imunodeficiência Adquirida dos Símios/genética , Vírus da Imunodeficiência Símia , Alelos , Animais , Antígenos CD4/química , Evolução Molecular , Produtos do Gene env/química , Humanos , Ligação Proteica , Domínios Proteicos
4.
J Hum Evol ; 151: 102930, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33422741

RESUMO

Pliopithecoids are an extinct group of catarrhine primates from the Miocene of Eurasia. More than 50 years ago, they were linked to hylobatids due to some morphological similarities, but most subsequent studies have supported a stem catarrhine status, due to the retention of multiple plesiomorphic features (e.g., the ectotympanic morphology) relative to crown catarrhines. More recently, some morphological similarities to hominoids have been noted, raising the question of whether they could be stem members of this clade. To re-evaluate these competing hypotheses, we examine the morphology of the semicircular canals of the bony labyrinth of the middle Miocene pliopithecid Epipliopithecus vindobonensis. The semicircular canals are suitable to test between these hypotheses because (1) they have been shown to embed strong phylogenetic signal and reliably discriminate among major clades; (2) several potential hominoid synapomorphies have been identified previously in the semicircular canals; and (3) semicircular canal morphology has not been previously described for any pliopithecoid. We use a deformation-based (landmark-free) three-dimensional geometric morphometric approach to compare Epipliopithecus with a broad primate sample of extant and extinct anthropoids. We quantify similarities in semicircular canal morphology using multivariate analyses, reconstruct ancestral morphotypes by means of a phylomorphospace approach, and identify catarrhine and hominoid synapomorphies based on discrete characters. Epipliopithecus semicircular canal morphology most closely resembles that of platyrrhines and Aegyptopithecus due to the retention of multiple anthropoid symplesiomorphies. However, Epipliopithecus is most parsimoniously interpreted as a stem catarrhine more derived than Aegyptopithecus due to the possession of a crown catarrhine synapomorphy (i.e., the rounded anterior canal), combined with the lack of other catarrhine and any hominoid synapomorphies. Some similarities with hylobatids and atelids are interpreted as homoplasies likely related to positional behavior. The semicircular canal morphology of Epipliopithecus thus supports the common view that pliopithecoids are stem catarrhines.


Assuntos
Catarrinos/anatomia & histologia , Fósseis/anatomia & histologia , Filogenia , Vestíbulo do Labirinto/anatomia & histologia , Animais
5.
BMC Biol ; 19(1): 6, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33461551

RESUMO

BACKGROUND: The two main primate groups recorded throughout the European Miocene, hominoids and pliopithecoids, seldom co-occur. Due to both their rarity and insufficiently understood palaeoecology, it is currently unclear whether the infrequent co-occurrence of these groups is due to sampling bias or reflects different ecological preferences. Here we rely on the densely sampled primate-bearing sequence of Abocador de Can Mata (ACM) in Spain to test whether turnovers in primate assemblages are correlated with palaeoenvironmental changes. We reconstruct dietary evolution through time (ca. 12.6-11.4 Ma), and hence climate and habitat, using tooth-wear patterns and carbon and oxygen isotope compositions of enamel of the ubiquitous musk-deer Micromeryx. RESULTS: Our results reveal that primate species composition is strongly correlated with distinct environmental phases. Large-bodied hominoids (dryopithecines) are recorded in humid, densely-forested environments on the lowermost portion of the ACM sequence. In contrast, pliopithecoids inhabited less humid, patchy ecosystems, being replaced by dryopithecines and the small-bodied Pliobates toward the top of the series in gallery forests embedded in mosaic environments. CONCLUSIONS: These results support the view that pliopithecoid primates preferred less humid habitats than hominoids, and reveal that differences in behavioural ecology were the main factor underpinning their rare co-occurrence during the European Miocene. Our findings further support that ACM hominoids, like Miocene apes as a whole, inhabited more seasonal environments than extant apes. Finally, this study highlights the importance of high-resolution, local investigations to complement larger-scale analyses and illustrates that continuous and densely sampled fossiliferous sequences are essential for deciphering the complex interplay between biotic and abiotic factors that shaped past diversity.


Assuntos
Evolução Biológica , Catarrinos/fisiologia , Dieta/veterinária , Traços de História de Vida , Animais , Ecossistema , Fósseis , Espanha
6.
J Hum Evol ; 151: 102941, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33482561

RESUMO

Recent studies on hominin craniofacial evolution have focused on phenotypic integration or covariation among traits. Covariation is thought to significantly affect evolutionary trajectories, shaping the ways in which hominins and other primates could have evolved. However, the ways in which covariation itself evolves are not well understood. This study aims to investigate the role of phylogeny, development, body size, and positional behavior in shaping the strength of covariation in strepsirrhine and catarrhine primate crania (n = 1009, representing 11 genera). These factors may have been catalysts for change in the magnitude of covariation, and they have changed significantly during primate evolution and particularly hominin evolution. Modern humans in particular have slow developmental trajectories, large bodies, and a unique form of locomotion in the form of orthograde bipedalism. Variance of eigenvalues, mean integration, mean evolvability, and mean conditional evolvability was estimated and their relationship to the various factors described earlier was assessed using phylogenetic and nonphylogenetic analyses. Results indicate that some phylogenetic signal is present, but it is not equivalent across integration statistics or cranial regions. In particular, these results suggest that closely related species are more similar than more distantly related species in evolvability of the cranial base and integration of the face. Two divergent patterns were also identified, in which covariation and evolvability of the cranial base are linked to developmental rate, but those of the face are linked to body size. Neither locomotion nor posture appears related to covariation or evolvability of the primate cranium. These results suggest that overall low covariation observed in the hominin cranium may be a result of separate trends in different cranial regions.


Assuntos
Evolução Biológica , Tamanho Corporal , Catarrinos/fisiologia , Locomoção , Crânio/anatomia & histologia , Strepsirhini/fisiologia , Animais , Catarrinos/anatomia & histologia , Catarrinos/crescimento & desenvolvimento , Strepsirhini/anatomia & histologia , Strepsirhini/crescimento & desenvolvimento
7.
J Anat ; 238(3): 693-710, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33084028

RESUMO

In studies of ontogenetic allometry, ontogenetic scaling has often been invoked to explain cranial morphological differences between smaller and larger forms of closely related taxa. These scaled variants in shape have been hypothesized to be the result of the extension or truncation of common growth allometries. In this scenario, change in size is the determining factor, perhaps under direct selection, and changes in cranial shapes are byproducts, not under direct selection themselves. However, many of these conclusions are based on studies that used bivariate generalizations of shape. Even among multivariate analyses of growth allometries, there are discrepancies as to the prevalence of ontogenetic scaling among primates, how shared the trajectories need to be, and which taxa evince properties of scaled variants. In this investigation, we use a large, comparative ontogenetic sample, geometric morphometric methods, and multivariate statistical tests to examine ontogenetic allometry and evaluate if differences in cranial shape among closely related catarrhines of varying sizes are primarily driven by size divergence, that is, ontogenetic scaling. We then evaluate the hypothesis of size as a line of least evolutionary resistance in catarrhine cranial evolution. We found that patterns of ontogenetic allometry vary among taxa, indicating that ontogenetic scaling sensu stricto does not often account for most morphological differences and that large and small taxa within clades are generally not scaled variants. The presence of a variety of ontogenetic pathways for the evolution of cranial shapes provides indirect evidence for selection acting directly on the cranial shape, rather than on size alone.


Assuntos
Catarrinos/crescimento & desenvolvimento , Crânio/crescimento & desenvolvimento , Animais , Biometria , Feminino , Masculino
8.
Elife ; 92020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32930662

RESUMO

Host antiviral proteins engage in evolutionary arms races with viruses, in which both sides rapidly evolve at interaction interfaces to gain or evade immune defense. For example, primate TRIM5α uses its rapidly evolving 'v1' loop to bind retroviral capsids, and single mutations in this loop can dramatically improve retroviral restriction. However, it is unknown whether such gains of viral restriction are rare, or if they incur loss of pre-existing function against other viruses. Using deep mutational scanning, we comprehensively measured how single mutations in the TRIM5α v1 loop affect restriction of divergent retroviruses. Unexpectedly, we found that the majority of mutations increase weak antiviral function. Moreover, most random mutations do not disrupt potent viral restriction, even when it is newly acquired via a single adaptive substitution. Our results indicate that TRIM5α's adaptive landscape is remarkably broad and mutationally resilient, maximizing its chances of success in evolutionary arms races with retroviruses.


Assuntos
Catarrinos/genética , Interações Hospedeiro-Patógeno , Mutação/genética , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Animais , Antivirais , Células Cultivadas , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Retroviridae/imunologia , Proteínas com Motivo Tripartido/química , Proteínas com Motivo Tripartido/genética , Proteínas com Motivo Tripartido/imunologia , Proteínas com Motivo Tripartido/metabolismo , Ubiquitina-Proteína Ligases/química , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/imunologia , Ubiquitina-Proteína Ligases/metabolismo , Viroses/imunologia
9.
J Hum Evol ; 145: 102838, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32659499

RESUMO

A diversity of pliopithecoids is known from Miocene localities in Europe, but until recently, this group was relatively poorly represented in China. However, new discoveries have shown that Chinese pliopithecoids were taxonomically diverse and geographically widespread. The earliest pliopithecoids in China (and Eurasia) are Dionysopithecus and Platodontopithecus from the Early Miocene of Sihong, Jiangsu (∼19-18 Ma). During the Middle Miocene (∼15-12 Ma), several species of pliopithecoids are recorded at localities in Gansu Province (Laogou), Inner Mongolia (Damiao), Xinjiang Uygur Autonomous Region (Tieersihabahe), and Ningxia Hui Autonomous Region (Tongxin). Finally, a late-surviving anapithecine crouzeliid, Laccopithecus robustus, is known from the Late Miocene (∼7 Ma) of Shihuiba in Yunnan, which postdates the extinction of pliopithecoids in Europe (during MN 10). Paleontological investigations at a late Early Miocene locality near Fanchang in Anhui Province have yielded a large sample of isolated teeth (more than one hundred) of a previously unknown species of pliopithecoid. The associated micromammals indicate an age contemporaneous with the Shanwang Formation in Shandong Province (MN 3-4, ∼18-17 Ma). All of the permanent teeth are represented except for I2. With its unique suite of dental features, the Fanchang pliopithecoid can be attributed to a new species and genus. Shared derived features of the lower molars confirm that the Fanchang pliopithecoid has its closest affinities with European crouzeliids, but a number of primitive traits indicate that it is a stem member of the clade. The evidence points to China as an important center for the early diversification of pliopithecoids. Contrary to previous zoogeographic scenarios, the occurrence of an early crouzeliid in China implies that the Pliopithecidae and Crouzeliidae may have diverged from a stem pliopithecoid in Asia during the Early Miocene before their arrival in Europe.


Assuntos
Catarrinos/anatomia & histologia , Catarrinos/classificação , Fósseis/anatomia & histologia , Dente Molar/anatomia & histologia , Coroa do Dente/anatomia & histologia , Animais , China , Feminino , Sedimentos Geológicos/análise , Masculino
10.
Am J Primatol ; 82(8): e23157, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32515849

RESUMO

Knowledge of niche partitioning with respect to habitat is indispensable to understand the mechanism of coexistence of multiple species. Among primates, however, data are still deficient because repeated survey for a sufficiently long time, covering seasonal changes over a large area, is the only way to clarify habitat segregation within a seasonally fluctuating environment. Southeast Asia is particularly interesting because of the supra-annual, highly unpredictable seasonality in fruiting known as mast fruiting. We conducted repeated route census, habitat monitoring, and group tracking for 25 months in two study sites (ca. 10 km apart) in the largely primary lowland dipterocarp forest of the Danum Valley Conservation Area, eastern Sabah, northern Borneo, Malaysia. The five species of diurnal primates (Bornean orangutan Pongo pygmaeus, Müeller's gibbon Hylobates muelleri, red leaf monkey Presbytis rubicunda, long-tailed macaque Macaca fascicularis, and southern pig-tailed macaque M. nemestrina) did not show horizontal spatial segregation. Red leaf monkeys showed preferences for places with short tree height, but their distribution was not confined to such places. In response to the fruiting peak observed once during the study period, orangutans increased their numbers simultaneously in the two study sites. The average tree height used by the five species was different, but their range overlapped substantially. Compared with other primate communities, the lack of horizontal spatial segregation and the suggested long-distance movement of orangutans seem to be unique characteristics in Borneo, although the use of different forest strata is a widespread phenomenon among primate communities throughout the world.


Assuntos
Catarrinos/fisiologia , Ecossistema , Distribuição Animal , Animais , Bornéu , Comportamento Alimentar , Frutas/crescimento & desenvolvimento , Malásia , Árvores
11.
Am J Phys Anthropol ; 173(1): 34-49, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32170728

RESUMO

OBJECTIVES: Epigenetic mechanisms influence the development and maintenance of complex phenotypes and may also contribute to the evolution of species-specific phenotypes. With respect to skeletal traits, little is known about the gene regulation underlying these hard tissues or how tissue-specific patterns are associated with bone morphology or vary among species. To begin exploring these topics, this study evaluates one epigenetic mechanism, DNA methylation, in skeletal tissues from five nonhuman primate species which display anatomical and locomotor differences representative of their phylogenetic groups. MATERIALS AND METHODS: First, we test whether intraspecific variation in skeletal DNA methylation is associated with intraspecific variation in femur morphology. Second, we identify interspecific differences in DNA methylation and assess whether these lineage-specific patterns may have contributed to species-specific morphologies. Specifically, we use the Illumina Infinium MethylationEPIC BeadChip to identify DNA methylation patterns in femur trabecular bone from baboons (n = 28), macaques (n = 10), vervets (n = 10), chimpanzees (n = 4), and marmosets (n = 6). RESULTS: Significant differentially methylated positions (DMPs) were associated with a subset of morphological variants, but these likely have small biological effects and may be confounded by other variables associated with morphological variation. Conversely, several species-specific DMPs were identified, and these are found in genes enriched for functions associated with complex skeletal traits. DISCUSSION: Overall, these findings reveal that while intraspecific epigenetic variation is not readily associated with skeletal morphology differences, some interspecific epigenetic differences in skeletal tissues exist and may contribute to evolutionarily distinct phenotypes. This work forms a foundation for future explorations of gene regulation and skeletal trait evolution in primates.


Assuntos
Catarrinos , Metilação de DNA/genética , Epigenoma/genética , Fêmur/anatomia & histologia , Animais , Catarrinos/anatomia & histologia , Catarrinos/classificação , Catarrinos/genética , Feminino , Proteínas de Homeodomínio/genética , Masculino , Fatores de Transcrição/genética
12.
Am J Phys Anthropol ; 171(2): 198-218, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31762014

RESUMO

OBJECTIVES: This study aimed to test the taxonomic utility of the catarrhine supraorbital region using 3D geometric morphometrics, with the aim of establishing its potential use in elucidating the position of more debated hominin groups. MATERIALS AND METHODS: 230 3D coordinates were used to record the supraorbital morphology of two datasets: one containing 460 non-hominin catarrhine primates from species and subspecies of Gorilla, Pan, Papio, and Macaca; and the other containing 55 Pleistocene hominins from Homo, Australopithecus, and Paranthropus. Principal component analyses in tangent, form, and allometry-free shape space were used to assess differentiation of taxa, with biological distinctiveness of taxa being established using step-wise discriminant analysis with subsampling. RESULTS: Results indicated that the recorded supraorbital morphology could be used to separate non-hominin catarrhine primate genera, species, and subspecies, although accuracy was found to decrease with decreasing Linnaean rank. In addition, analyses in tangent space were found to produce the highest accuracy when classifying primates of known taxonomy. Biological distinctiveness of the middle and later Homo species was comparable to or higher than that of the non-hominin primates, and relatively lower for the earlier groups of Homo. DISCUSSION: This study indicates that the supraorbital region preserves taxonomic information that can be used to delineate between closely related groups, both within hominins and wider catarrhine primates. Therefore, this region may be used to provide insight when assessing the taxonomic affiliation of disputed hominin specimens.


Assuntos
Catarrinos/anatomia & histologia , Órbita/anatomia & histologia , Animais , Catarrinos/classificação , Feminino , Fósseis/anatomia & histologia , Masculino , Crânio/anatomia & histologia
13.
J Hum Evol ; 132: 227-246, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31203849

RESUMO

The early Miocene site of Moroto II, Uganda has yielded some of the oldest known hominoid fossils. A new partial mandible (UMP MORII 03'551) is notable for its long tooth row and large, narrow M2 with well-developed cristids - a morphological combination previously unknown for large bodied catarrhines of the Early Miocene and suggesting folivory. The tooth proportions are compatible with belonging to the same taxon as the maxilla UMP 62-11, the holotype of Morotopithecus bishopi; likewise, the long tooth row and vertical planum of UMP MORII 03'551 suggest that it may represent the same taxon as mandible(s) UMP 66-01 and UMP 62-10. Canine size strongly suggests UMP MORII 03'551 is a female. Comparisons of the tooth crown morphology and tooth row proportions, relative enamel thickness, enamel-dentine junction morphology, long-period line periodicity, and dental wear patterns support significant morphological, developmental, and inferred dietary differentiation, and therefore generic-level distinctiveness, among Afropithecus, Morotopithecus and the Proconsul clade. An isolated M1 (UMP MORII 03'559) is morphologically dissimilar, and much smaller than the actual or inferred size of molars in UMP MORII 03'551, UMP 66-01 and UMP 62-10, supporting the presence of two hominoid taxa at Moroto II, M. bishopi and a smaller bodied proconsulid. Given the high level of body mass dimorphism inferred for Morotopithecus and other early Miocene catarrhines, the known postcrania from Moroto II could be attributable to either taxon. However, UMP MORII 03'551 and the femora UMP MORII 94'80 derive from the same stratigraphic interval, while the isolated M1 was deposited later, increasing the likelihood that the mandible and femora are from the same individual. These new fossils expand our understanding of the taxonomic and adaptive diversity of early Miocene catarrhines.


Assuntos
Catarrinos/anatomia & histologia , Fósseis/anatomia & histologia , Mandíbula/anatomia & histologia , Dente/anatomia & histologia , Animais , Catarrinos/classificação , Feminino , Masculino , Uganda
14.
Anat Rec (Hoboken) ; 302(11): 1977-1984, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31120200

RESUMO

Previous investigations of the primate talo-crural joint (TCJ; specifically on the talus and distal tibia) have demonstrated that substrate preference significantly influences morphology, but this association is not necessarily found in subadults. This has been interpreted as the result of a plastic, behaviorally induced response of bone due to substrate use. In this investigation, we use geometric morphometric and phylogenetic comparative methods to investigate ontogenetic phenotypic plasticity in the catarrhine TCJ. Osteological specimens from four African hominoid and four cercopithecid species, divided into subadult and adult developmental stages based on molar eruption, formed the study group. We tested for phylogenetic signal in the shape of both the talar and tibial articular surfaces, at both developmental stages. We then used phylomorphospaces to examine the evolution of shape differences at each developmental stage for each element, and to determine if substrate usage is associated with shape in this phylogenetic context. A significant phylogenetic signal was found for both articular surfaces in subadults, but not adults. In phylomorphospace, both talar and tibial articular morphologies show an association with substrate preference in adults, but not in subadults. Our results provide confirmation of the significant effect of habitual substrate usage and the consequences of bone remodeling during ontogeny on the shape and presentation of the TCJ. These results also suggest caution when using adult talo-tibial shapes to evaluate phylogenetic relationships as TCJ morphology can be considered as a palimpsest, with substrate usage overwriting phylogenetic information in adult specimens. Anat Rec, 302:1977-1984, 2019. © 2019 American Association for Anatomy.


Assuntos
Adaptação Fisiológica , Articulação do Tornozelo/anatomia & histologia , Evolução Biológica , Catarrinos/anatomia & histologia , Filogenia , Tálus/anatomia & histologia , Animais
15.
J Hum Evol ; 128: 59-75, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30825982

RESUMO

Kamoyapithecus hamiltoni is a potential early hominoid species described from fragmentary dentognathic specimens from the Oligocene site of Losodok (Turkana Basin, northwestern Kenya). Other catarrhine dental materials have been recovered at Losodok, but were not initially included in the Kamoyapithecus hypodigm. Here we present descriptions of the unpublished canine and incisor specimens from Losodok, and revisit the published specimens in light of recent changes in understanding of hominoid anterior dental evolution. The new fossils include a canine (KNM-LS 18354) that is morphologically compatible with being a female of Kamoyapithecus (KNM-LS 8). Randomization analyses of both Gorilla gorilla and middle Miocene Griphopithecus alpani demonstrate that the size difference between KNM-LS 8 and KNM-LS 18354 is also compatible with their being male and female canines of the same species. Significantly, a canine tip (KNM-LS 18352) attributed to Kamoyapithecus documents the distinctive burin tip morphology now recognized as characterizing Proconsul sensu stricto, which may indicate a close relationship between Kamoyapithecus and Proconsul. We also re-examined the enigmatic KNM-LS 1, a smaller lower canine assumed to derive from Losodok but for which historical provenience data are completely lacking. Elemental data derived from portable X-ray fluorescence spectroscopy show that KNM-LS 1 is almost certainly from Losodok rather than from nearby Miocene sites (i.e., Moruorot, Esha, Kalodirr). KNM-LS 1 displays a nyanzapithecine-like morphology and is shown by randomization analyses to be too small to be associated with the Kamoyapithecus canines. This demonstrates that there is a second hominoid taxon present at Losodok that records one of the earliest occurrences of the Nyanzapithecinae.


Assuntos
Catarrinos/anatomia & histologia , Fósseis/anatomia & histologia , Dente/anatomia & histologia , Animais , Evolução Biológica , Feminino , Quênia , Masculino
16.
Am J Primatol ; 81(3): e22953, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30664271

RESUMO

The reduction in dental size and mandibular robusticity is regarded as a major trend in human evolution, traditionally considered the result of the peculiar extra-oral food processing skills of Homo. The use of stone tools and fire would have allowed our ancestors to chew softer food in smaller bite size, thus relaxing the selective pressures to keep a large dentition and a robust lower jaw. This perspective assumes that differences in dental size and mandibular robusticity in hominins represent functional dissimilarities. This study uses a catarrhine comparative approach to test this fundamental assumption of the hypotheses on dental and mandibular reduction in Homo. A sample of extant catarrhines and fossil hominins was used to test for correlations between dental size, mandibular robusticity, and dietary proxies, the latter include diet quality, diet heterogeneity, feeding time, and microwear variables. The effects of phylogeny and body size were considered. Findings support the association between technological developments in Homo and reduction in incisor size and mandibular corpus robusticity, though not for premolar, molar size, and symphyseal robusticity. These results challenge the functional interpretation of postcanine reduction and symphyseal changes in the genus Homo.


Assuntos
Evolução Biológica , Dentição , Hominidae/anatomia & histologia , Mandíbula/anatomia & histologia , Animais , Tamanho Corporal , Catarrinos/anatomia & histologia , Catarrinos/classificação , Dieta , Fósseis , Hominidae/classificação , Filogenia
17.
Am J Phys Anthropol ; 168(1): 131-144, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30408150

RESUMO

OBJECTIVES: We tested whether patterns of intraspecific variation in catarrhine vertebral shape are consistent with developmental or functional predictions. Intraspecific variation was compared across column regions, morphological features, and species. Transitional regions and later ossifying morphological features were predicted to exhibit increased variation. The lumbosacral region, biomechanically important morphological features, and species with high locomotor demand and/or dedicated pronogrady were predicted to exhibit decreased variation. MATERIALS AND METHODS: We used a modified Levene's test to compare intraspecific variation in dimensions of the neural canal, vertebral bodies, and spinous and transverse processes in lower thoracic to proximal sacral vertebrae. The sample included all hominoid genera and one cercopithecoid (Chlorocebus). RESULTS: We found little difference in variation across regions of the vertebral column. In hominoids, vertebral body dimensions were the least variable, neural canal dimensions the most variable, with spinous and transverse processes generally intermediate. Among species, there was a general though not always significant pattern for Chlorocebus to exhibit the least variation, followed by Homo or Hylobates. DISCUSSION: Patterns of variation across morphological features may reflect the complex interaction of functional constraints, developmental timing, and/or variable biomechanical forces. Pongo's elevated variation in spinous process length suggests a release from functional constraint, consistent with its suspensory locomotion and reduced spinous processes. Interspecific differences in vertebral variation based on locomotor demand or posture are generally consistent with patterns previously reported for vertebral formula and other aspects of morphology. Future research would benefit from an expanded taxonomic sample and more detailed analyses of vertebral modularity and developmental timing.


Assuntos
Catarrinos , Coluna Vertebral , Animais , Antropologia Física , Evolução Biológica , Catarrinos/anatomia & histologia , Catarrinos/crescimento & desenvolvimento , Catarrinos/fisiologia , Humanos , Locomoção , Especificidade da Espécie , Coluna Vertebral/anatomia & histologia , Coluna Vertebral/crescimento & desenvolvimento , Coluna Vertebral/fisiologia
18.
J Hum Evol ; 125: 50-58, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30502897

RESUMO

A new species of the "small-bodied ape" Simiolus is described here that extends the temporal range of the genus to the end of the Middle Miocene. As such, it is one of the few species of fossil primates known from East Africa during a time of significant change in which Old World monkeys and crown hominoids replaced the primitive ape-like primates that had dominated the early Miocene. The dynamics of this important event in our evolutionary history are obscured by the small number of fossil primates known from Africa between 14 and 6 million years ago, as well as persistent ambiguity regarding the phylogenetic status of the ape-like Miocene primates. The new species described here helps to fill this temporal gap, and our analysis of its phylogenetic position suggests that Simiolus and many other Miocene primates were not only ape-like, they were, indeed, stem hominoids. Judging from the available material, the new species may be the smallest known ape.


Assuntos
Catarrinos/classificação , Fósseis/anatomia & histologia , Animais , Catarrinos/anatomia & histologia , Quênia , Paleontologia , Filogenia
19.
Mol Biol Evol ; 35(12): 2886-2899, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30252115

RESUMO

The competitive endogenous RNA (ceRNA) hypothesis is an attractively simple model to explain the biological role of many putatively functionless noncoding RNAs. Under this model, there exist transcripts in the cell whose role is to titrate out microRNAs such that the expression level of another target sequence is altered. That it is logistically possible for expression of one microRNA recognition element (MRE)-containing transcript to affect another is seen in the multiple examples of pathogenic effects of inappropriate expression of MRE-containing RNAs. However, the role, if any, of ceRNAs in normal biological processes and at physiological levels is disputed. By comparison of parent genes and pseudogenes we show, both for a specific example and genome-wide, that the pseudo-3' untranslated regions (3'UTRs) of expressed pseudogenes are frequently retained and are under selective constraint in mammalian genomes. We found that the pseudo-3'UTR of BRAFP1, a previously described oncogenic ceRNA, has reduced substitutions relative to its pseudo-coding sequence, and we show sequence constraint on MREs shared between the parent gene, BRAF, and the pseudogene. Investigation of RNA-seq data reveals expression of BRAFP1 in normal somatic tissues in human and in other primates, consistent with biological ceRNA functionality of this pseudogene in nonpathogenic cellular contexts. Furthermore, we find that on a genome-wide scale pseudo-3'UTRs of mammalian pseudogenes (n = 1,629) are under stronger selective constraint than their pseudo-coding sequence counterparts, and are more often retained and expressed. Our results suggest that many human pseudogenes, often considered nonfunctional, may have an evolutionarily constrained role, consistent with the ceRNA hypothesis.


Assuntos
Catarrinos/genética , Evolução Molecular , Regulação da Expressão Gênica , Proteínas Proto-Oncogênicas B-raf/genética , Pseudogenes , Regiões 3' não Traduzidas , Animais , Sequência de Bases , Humanos
20.
Am J Phys Anthropol ; 166(4): 987-993, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29577230

RESUMO

OBJECTIVES: High-resolution imaging of fossils with X-ray computed microtomography (µCT) has become a very powerful tool in paleontological research. However, fossilized bone, embedding matrix, and dental tissues do not always provide a distinct structural signal with X-rays. We demonstrate the benefits of high-resolution neutron radiation in three different specimens showing problematic contrasts with X-ray µCT. MATERIALS AND METHODS: We compare neutron with X-ray µCT scans of fossils from two Miocene catarrhines from the Vallès-Penedès Basin: the cranium (IPS58443.1, holotype) of the putative stem hominoid Pliobates cataloniae, to discriminate between bone and matrix; and two lower molars (IPS1724n,o, holotype) of Barberapithecus huerzeleri, to discriminate among dental tissues. RESULTS: X-ray µCT scans of these specimens fail to retrieve any contrast between matrix/bone and enamel/dentine, whereas neutron µCT scans deliver high-contrast images, enabling a proper evaluation of the specimens' internal anatomy. DISCUSSION: Low bone/matrix intensity difference with X-ray µCT scans in IPS58443.1 is due to the extreme similarity in chemical composition between the matrix and the fossilized tissues, and the presence of high-density elements. In IPS1724, it is attributable to the convergence of enamel and dentine compositions during fossilization. On the contrary, neutron radiation returns very different contrasts for different isotopes of the same element and easily penetrates most metals. Neutron-based µCT scans therefore enable a correct definition of the bone/sediment and enamel/dentine interfaces, and hence a better segmentation of the images stack. We conclude that neutron radiation represents a successful alternative for high-resolution µCT of small-sized fossils that are problematic with X-rays.


Assuntos
Catarrinos/anatomia & histologia , Fósseis , Nêutrons , Microtomografia por Raio-X/métodos , Animais , Antropologia Física , Osso e Ossos/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Espanha
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