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1.
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
2.
J Med Primatol ; 50(1): 21-28, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33063350

RESUMO

BACKGROUND: Recently, some studies about primates have claimed the importance of the vessels to maintain the muscles working; in fact, the arterial supply could suggest how strenuous the muscular performance is associated to locomotor behavior. The aim of this work was to study the anatomy of the arteries of the forelimbs of different groups of primates to evidence a general arterial model in comparative terms. METHODS: We propose a biophysical explanation for the arterial pattern of the forelimbs of primates' groups. RESULTS: Three pattern of the forelimb arteries in Primates were descript and the differences were explained using mathematical formulas. CONCLUSIONS: The anatomical study about the comparative anatomy of the arteries of the forelimbs of primates provided hypothesis about the three observed models, mainly in relation to brachial artery division and the number of the palmar arches, in mathematical models' terms.


Assuntos
Membro Anterior/irrigação sanguínea , Macaca/anatomia & histologia , Pan troglodytes/anatomia & histologia , Papio/anatomia & histologia , Sapajus/anatomia & histologia , Animais , Feminino , Humanos , Masculino , Modelos Biológicos
3.
J Hum Evol ; 145: 102799, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32619882

RESUMO

Papio originated in the early Pleistocene and diverged into multiple species, six of which are extant. Among parapatric Papio species, there are obvious phenotypic differences that arose during the radiation of the genus. We use data from modern baboon ecology and morphology, as well as fossils and paleoecology, to examine baboon biogeography, divergence, and evolution, focusing on skull form and body mass. To provide context, techniques of historical biogeography, combining data from modern distributions in statistical models alongside qualitative assessments of the fossil record, were used to estimate ancestral ranges in papionins. The ancestral range of Papio was estimated to be in South Tropical Africa rather than in the far south of the continent, followed by multiple movements south and west. Progress to the north and east may have been slowed because of high-density blocking of niches by other monkeys. Geometric morphometric data were used in partial least squares analysis with dietary, environmental, and other variables to investigate skull differentiation. Environment was significantly correlated with skull form, but diet emerged as more significant. Exploitation of subterranean foods was found to be an important influence on skull morphology. Bayesian modeling of cercopithecid body mass data allowed reconstruction of ancestral body mass and showed a pattern of accelerating body mass evolution in a number of lineages. This appears to be related to exploitation of terrestrial niches in the Pliocene, with terrestriality also implicated in the large geographic distributions of many fossil and modern papionins, including Papio. Given the greater heterogeneity of body masses in males, size differentiation within Papio seems most likely to be linked to sexual selection rather than environmental factors, although further work is required to examine the relative importance of plasticity versus local adaptation in shaping baboon phenotypic variation.


Assuntos
Evolução Biológica , Fósseis/anatomia & histologia , Papio/anatomia & histologia , Migração Animal , Animais , Tamanho Corporal/fisiologia , Feminino , Masculino , Filogeografia , Crânio/anatomia & histologia , África do Sul
4.
PLoS One ; 15(3): e0229244, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32126093

RESUMO

The outer cortical table of the parietal bone has been commonly used as a calvarial bone graft site for the craniofacial reconstruction. However, little is known about how removing the outer table may affect the function and structure of the inner table, and how the knowledge of the biomechanics and material properties of cortical bones will help the calvarial graft to better integrate into the biological and mechanical functions of its surrounding native tissues. In this study, it was hypothesized that there were significant differences in both density and material properties between inner and outer cortical plates in cranial bones. Twelve cylindrical specimens, including inner-outer layers, of cortical parietal bone of a female baboon were collected. Cortical thicknesses and densities were measured, and elastic properties were assessed using an ultrasonic technique. Results demonstrated remarkable difference in both thickness (t = 8.248, p ≤0.05) and density (t = 4.926, p≤0.05) between inner and outer cortical paired samples. Orthotropic characteristics of the cortical plates were detected as well, these findings suggest that there are differences in biomechanical properties between two surfaces of cranial bones at both tissue and organ levels. How these differences are linked to the stress environments of the inner and outer cranial cortical layers awaits further studies. Further study will greatly enhance our ability to address questions derived from both morphological and craniofacial medicine fields about the development and biomechanics of craniofacial skeletons.


Assuntos
Osso Cortical/ultraestrutura , Papio/anatomia & histologia , Osso Parietal/ultraestrutura , Animais , Fenômenos Biomecânicos , Densidade Óssea , Osso Cortical/fisiologia , Elasticidade , Feminino , Especificidade de Órgãos , Osso Parietal/fisiologia , Transdutores , Ultrassom
5.
J Comp Neurol ; 528(5): 772-786, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-31600841

RESUMO

Nonpyramidal GABAergic interneurons in the basolateral nuclear complex (BNC) of the amygdala are critical for the regulation of emotion. Remarkably, there have been no Golgi studies of these neurons in nonhuman primates. Therefore, in the present study we investigated the morphology of nonpyramidal neurons (NPNs) in the BNC of the baboon and monkey using the Golgi technique. NPNs were scattered throughout all nuclei of the BNC and had aspiny or spine-sparse dendrites. NPNs were morphologically heterogeneous and could be divided into small, medium, large, and giant types based on the size of their somata. NPNs could be further divided on the basis of their somatodendritic morphology into four types: multipolar, bitufted, bipolar, and irregular. NPN axons, when stained, formed dense local arborizations that overlapped their dendritic fields to varying extents. These axons always exhibited varying numbers of varicosities representing axon terminals. Three specialized NPN subtypes were recognized because of their unique anatomical features: axo-axonic cells, neurogliaform cells, and giant cells. The axons of axo-axonic cells formed "axonal cartridges," with clustered varicosities that contacted the axon initial segments of pyramidal neurons (PNs). Neurogliaform cells had small somata and numerous short dendrites that formed a dense dendritic arborization; they also exhibited a very dense axonal arborization that overlapped the dendritic field. Giant cells had very large irregular somata and long, thick dendrites; their distal dendrites often branched extensively and had long appendages. In general, the NPNs of the baboon and monkey BNC, including the specialized subtypes, were similar to those of rodents.


Assuntos
Complexo Nuclear Basolateral da Amígdala/citologia , Neurônios GABAérgicos/citologia , Macaca fascicularis/anatomia & histologia , Papio/anatomia & histologia , Coloração e Rotulagem/métodos , Animais , Masculino
6.
Anat Rec (Hoboken) ; 303(1): 129-149, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-30548834

RESUMO

Trabecular bone structure has been used to investigate the relationship between skeletal form and locomotor behavior on the premise that trabecular bone remodels in response to loading during an animal's lifetime. The aim of this study is to characterize human distal femoral trabecular bone structure in comparison to three non-human primate taxa and relate the patterns of trabecular structural variation in the distal femur to knee posture during habitual locomotor behavior. A whole-epiphysis approach was applied using microCT scans of the distal femora of extant Homo sapiens, Pan troglodytes, Pongo pygmaeus, and Papio spp. (N = 48). Bone volume fraction (BV/TV) was quantified in the epiphysis and analyzed with both whole-condyle and a novel sector analysis. The results indicate high trabecular bone structural variation within and between species. The sector analysis reveals the most distinctive patterns in the stereotypically loaded human knee, with a pattern of high BV/TV distally. In general, Pan, Pongo, and Papio show evidence of flexed knee postures, typical of their locomotor behaviors, with regions of high BV/TV posteriorly within the condyles. The pairwise comparisons confirm the unique pattern in Homo and reveal a shared high BV/TV region in the patellar groove of both Homo and Papio. The distinct pattern found in Homo relative to the other primate taxa suggests a plastic response to unique loading patterns during bipedal locomotion. Results may facilitate resolving the antiquity of habitual bipedality in the hominin fossil record. This analysis also presents new approaches for statistical analysis of whole-epiphysis trabecular bone structure. Anat Rec, 2018. © 2018 American Association for Anatomy.


Assuntos
Osso Esponjoso/anatomia & histologia , Fêmur/anatomia & histologia , Hominidae/anatomia & histologia , Locomoção/fisiologia , Papio/anatomia & histologia , Postura/fisiologia , Animais , Humanos
7.
Primates ; 60(5): 401-419, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31468228

RESUMO

Macaques are one of the most successful nonhuman primates, and morphological distinctions from their close relatives, African papionins, are easily detected by the naked eye. Nevertheless, evolutionary allometry often accounts for a large amount of the total variation and potentially hides and precludes the detection of morphological distinctions that exist between macaques and African papionins, thus distorting their phyletic comparison. Geometric morpgometric analyses were performed using landmark coordinates in cranial samples from macaques (N = 135) and African papionins (N = 152) to examine the variation in their facial shape. A common allometric trend was confirmed to represent a moderately long face in macaques as being small-to-moderate-bodied papionins. Macaques possessed many features that were distinct from those of African papionins, while they simultaneously showed a large intrageneric variation in every feature, which precluded the separation of some groups of macaques from African papionins. This study confirmed that a moderately smooth sagittal profile is present in non-Sulawesi macaques. It also confirmed that a well-developed anteorbital drop is distinct in Mandrillus and Theropithecus, but it showed that Papio resembles macaques regarding this feature. This finding showed that apparently equivalent features which can be detected by the naked eye were probably formed by different combinations of the principal patterns. It should be noted that the differences detected here between macaques and African papionins are revealed after appropriate adjustments are made to eliminate the allometric effects over the shape features. While landmark data sets still need to be customized for specific studies, the information provided by this article is expected to help such customization and to improve future phyletic evaluation of the fossil papionins.


Assuntos
Cercopithecinae/anatomia & histologia , Face/anatomia & histologia , Crânio/anatomia & histologia , África , Animais , Feminino , Macaca/anatomia & histologia , Masculino , Papio/anatomia & histologia
8.
Nat Commun ; 10(1): 3437, 2019 07 31.
Artigo em Inglês | MEDLINE | ID: mdl-31366944

RESUMO

Although the relative expansion of the frontal cortex in primate evolution is generally accepted, the nature of the human uniqueness, if any, and between-species anatomo-functional comparisons of the frontal areas remain controversial. To provide a novel interpretation of the evolution of primate brains, sulcal morphological variability of the medial frontal cortex was assessed in Old World monkeys (macaque/baboon) and Hominoidea (chimpanzee/human). We show that both Hominoidea possess a paracingulate sulcus, which was previously thought to be unique to the human brain and linked to higher cognitive functions, such as mentalizing. Also, we show systematic sulcal morphological organization of the medial frontal cortex that can be traced from Old World monkeys to Hominoidea species, demonstrating an evolutionarily conserved organizational principle. These data provide a new framework to compare sulcal morphology, cytoarchitectonic areal distribution, connectivity, and function across the primate order, leading to clear predictions about how other primate brains might be anatomo-functionally organized.


Assuntos
Mapeamento Encefálico , Macaca/anatomia & histologia , Pan troglodytes/anatomia & histologia , Papio/anatomia & histologia , Córtex Pré-Frontal/anatomia & histologia , Animais , Evolução Biológica , Cognição/fisiologia , Humanos , Processamento de Imagem Assistida por Computador , Neuroimagem
9.
J Hum Evol ; 135: 102635, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31421317

RESUMO

Due to wide variation in the presence and degree of expression of a diverse suite of sexually-selected traits, the tribe Papionini represents an outstanding model for understanding how variation in sexual selection pressures and mechanisms leads to trait evolution. Here, we discuss the particular value of Papio as a model genus for studies of sexual selection, emphasizing the presence of multiple mating systems, and differences in the expression of sexually-selected traits among closely-related species. We draw particular attention to the Kinda baboon (Papio kindae), a comparatively less-studied baboon species, by providing a primer to Kinda baboon morphology, genetics, physiology, and behavior. Based on observations of large group sizes, combined with low degrees of sexual dimorphism and large relative testis size relative to other baboon species, we test the hypothesis that Kinda baboons have evolved under reduced direct, and increased indirect, male-male competition. We present the first long-term data on wild Kinda baboons in Zambia. Kinda baboon females show seasonal peaks in births and reproductive receptivity, and males exhibit a queing-rather than contest-based dominance acquisition with long alpha-male tenure lengths. We finish by making a number of explicit testable predictions about Kinda baboon sexual signals and behaviors, and suggest that Kinda baboons have potential to offer new insights into the selective environments that may have been experienced during homininization.


Assuntos
Preferência de Acasalamento Animal , Papio/fisiologia , Animais , Feminino , Masculino , Papio/anatomia & histologia , Papio/genética , Fenótipo , Caracteres Sexuais , Zâmbia
10.
J Anat ; 235(2): 217-232, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31070786

RESUMO

Primate craniofacial growth is traditionally assumed to cease upon maturation or at least be negligible, whereas bony remodeling is typically associated with advanced adult age and, in particular, tooth loss. Therefore, size and shape of the craniofacial skeleton of young and middle-aged adults should be stable. However, research on both modern and historic human samples suggests that portions of the CFS exhibit age-related changes in mature individuals, both related to and independent of tooth loss. These results demonstrate that the age-category 'adult' is heterogeneous, containing individuals demonstrating post-maturational age-related variation, but the topic remains understudied outside of humans and in the cranial vault and base. Our research quantifies variation in a sample of captive adult female baboons (n = 97) in an effort to understand how advancing age alters the mature CFS. Craniometric landmarks and sliding semilandmarks were collected from computed tomography (CT) scans of adult baboons aged 7-32 years old. To determine whether craniofacial morphology is sensitive to aging mechanisms and whether any such effects are differentially distributed throughout the cranium, geometric morphometric techniques were employed to compare the shapes of various cranial regions among individuals of increasing age. Unexpectedly, the biggest form differences were observed between young and middle-aged adults, rather than between adults with full dentitions and those with some degree of tooth loss. Shape variation was greatest in masticatory and nuchal musculature attachment areas. Our results indicate that the craniofacial skeleton changes form during adulthood in baboons, raising interesting questions about the molecular and biological mechanisms governing these changes.


Assuntos
Envelhecimento/patologia , Papio/anatomia & histologia , Crânio/patologia , Animais , Feminino
11.
Sci Rep ; 8(1): 14052, 2018 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-30232366

RESUMO

This study aims to explore the feeding ecology of two terrestrial papionins, Papio and Theropithecus from the Shungura Formation in Ethiopia, the most complete stratigraphic and paleontological record of the African Plio-Pleistocene. Two aspects were evaluated using Dental Microwear Texture Analysis: differences in diet between the extinct genera and their extant relatives, and any potential dietary fluctuations over time. Amongst more than 2,500 cercopithecid dental remains, 154 Theropithecus molars and 60 Papio molars were considered. Thirty-nine extant wild baboons and 20 wild geladas were also considered. The results show that diets of extinct monkeys from Member G already differed between genera as it is the case for their extant representatives. The shearing facets on the Theropithecus molars display significant variations in microwear textures, suggesting several dietary shifts over time. Two events point to higher intakes of herbaceous monocots (tougher than dicots foliages), at about 2.91 Ma (between members B and C) and at 2.32 Ma (between members E and F). These two events are separated by an inverse trend at about 2.53 Ma (between members C and D). Some of these variations, such as between members E and F are supported by the enamel carbon isotopic composition of herbivorous mammals and with paleovegetation evidence.


Assuntos
Dieta , Dente Molar/ultraestrutura , Papio/fisiologia , Theropithecus/fisiologia , Animais , Evolução Biológica , Isótopos de Carbono/análise , Etiópia , Extinção Biológica , Fósseis , Herbivoria , Dente Molar/química , Papio/anatomia & histologia , Theropithecus/anatomia & histologia
12.
Anat Rec (Hoboken) ; 301(2): 325-342, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29330952

RESUMO

Numerous studies have sought to link craniofacial morphology with behavioral ecology in primates. Extant hard-object feeders have been of particular interest because of their potential to inform our understanding about the diets of early fossil hominins. Sooty mangabeys (Cercocebus atys) are hard-object feeders that frequently generate what have been described as audibly powerful bites at wide jaw gapes to process materially stiff and hard seeds. We address the hypothesis that sooty mangabeys have features of the masticatory apparatus that facilitate this feeding behavior by comparing fiber architecture and leverage of the masseter and temporalis muscles between sooty mangabeys and three papionin primates that do not specialize on hard objects. Contrary to predictions, sooty mangabeys do not have relatively larger muscle physiologic cross-sectional areas or weights compared to other papionins, nor do they consistently display improved leverage. In this regard, sooty mangabeys differ in their morphology from other hard-object feeders such as tufted capuchins. However, males of all four papionin species converge on a shared pattern of relatively longer anterior superficial masseter fibers compared with female conspecifics, suggesting that males are likely prioritizing muscle stretch to improve gape performance as part of a behavioral repertoire that includes agonistic social interactions and intense male-male competition. These findings strengthen support for the hypothesis that gape display behaviors can exert a strong selective influence throughout the musculoskeletal masticatory apparatus. Results also raise questions about the morphological suitability of extant cercopithecines as models for interpreting feeding behavior and diet in fossil hominins with limited jaw gape capacity. Anat Rec, 301:325-342, 2018. © 2018 Wiley Periodicals, Inc.


Assuntos
Força de Mordida , Cercocebus atys/anatomia & histologia , Arcada Osseodentária/anatomia & histologia , Macaca/anatomia & histologia , Músculo Masseter/anatomia & histologia , Mastigação/fisiologia , Papio/anatomia & histologia , Adaptação Fisiológica , Animais , Cercocebus atys/fisiologia , Dieta , Feminino , Arcada Osseodentária/fisiologia , Macaca/fisiologia , Masculino , Músculo Masseter/fisiologia , Papio/fisiologia
13.
Sci Rep ; 8(1): 1174, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29352119

RESUMO

The Old World non-human primates (NHP) - baboons (Papio spp.) share similarities with humans regarding fetal and placental development and some pregnancy-related complications. Information about the mechanism of birth and complications arising during parturition in these species is relatively sparse. In this manuscript, we add information from a series of pathological and observational cases to highlight insights and selected complications of birth in Papio spp, based on video-recording of the delivery process, X-ray, MRI, and ultrasound evaluations in pregnant baboons. Additionally, we abstracted pathology records obtained from perinatal loss in a large baboon colony during a 17 year period. The presented cases provide important information for the management of pregnancy and delivery in Papio spp.


Assuntos
Papio/fisiologia , Parto/fisiologia , Animais , Feminino , Idade Gestacional , Trabalho de Parto , Masculino , Papio/anatomia & histologia , Gravidez , Complicações na Gravidez
14.
Am J Phys Anthropol ; 165(2): 269-285, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29154459

RESUMO

OBJECTIVES: Determining the genetic architecture of quantitative traits and genetic correlations among them is important for understanding morphological evolution patterns. We address two questions regarding papionin evolution: (1) what effect do body and cranial size, age, and sex have on phenotypic (VP ) and additive genetic (VA ) variation in baboon crania, and (2) how might additive genetic correlations between craniofacial traits and body mass affect morphological evolution? MATERIALS AND METHODS: We use a large captive pedigreed baboon sample to estimate quantitative genetic parameters for craniofacial dimensions (EIDs). Our models include nested combinations of the covariates listed above. We also simulate the correlated response of a given EID due to selection on body mass alone. RESULTS: Covariates account for 1.2-91% of craniofacial VP . EID VA decreases across models as more covariates are included. The median genetic correlation estimate between each EID and body mass is 0.33. Analysis of the multivariate response to selection reveals that observed patterns of craniofacial variation in extant baboons cannot be attributed solely to correlated response to selection on body mass, particularly in males. DISCUSSION: Because a relatively large proportion of EID VA is shared with body mass variation, different methods of correcting for allometry by statistically controlling for size can alter residual VP patterns. This may conflate direct selection effects on craniofacial variation with those resulting from a correlated response to body mass selection. This shared genetic variation may partially explain how selection for increased body mass in two different papionin lineages produced remarkably similar craniofacial phenotypes.


Assuntos
Tamanho Corporal , Face/anatomia & histologia , Variação Genética , Papio , Crânio/anatomia & histologia , Animais , Antropologia Física , Evolução Biológica , Tamanho Corporal/genética , Tamanho Corporal/fisiologia , Cefalometria , Feminino , Variação Genética/genética , Variação Genética/fisiologia , Genética Populacional , Masculino , Papio/anatomia & histologia , Papio/genética , Papio/fisiologia
15.
PLoS One ; 12(1): e0169321, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28076426

RESUMO

Language is a distinguishing characteristic of our species, and the course of its evolution is one of the hardest problems in science. It has long been generally considered that human speech requires a low larynx, and that the high larynx of nonhuman primates should preclude their producing the vowel systems universally found in human language. Examining the vocalizations through acoustic analyses, tongue anatomy, and modeling of acoustic potential, we found that baboons (Papio papio) produce sounds sharing the F1/F2 formant structure of the human [ɨ æ ɑ ɔ u] vowels, and that similarly with humans those vocalic qualities are organized as a system on two acoustic-anatomic axes. This confirms that hominoids can produce contrasting vowel qualities despite a high larynx. It suggests that spoken languages evolved from ancient articulatory skills already present in our last common ancestor with Cercopithecoidea, about 25 MYA.


Assuntos
Evolução Biológica , Papio/fisiologia , Acústica da Fala , Fala/fisiologia , Vocalização Animal/fisiologia , Animais , Feminino , Humanos , Laringe/anatomia & histologia , Laringe/fisiologia , Masculino , Músculos/fisiologia , Papio/anatomia & histologia , Fonética , Língua/anatomia & histologia , Língua/fisiologia
16.
Am J Phys Anthropol ; 161(1): 72-83, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27252095

RESUMO

OBJECTIVES: Previous studies suggest that the postures habitually adopted by an animal influence the mechanical loading of its long bones. Relatively extended limb postures in larger animals should preferentially reduce anteroposterior (A-P) relative to mediolateral (M-L) bending of the limb bones and therefore decrease A-P/M-L rigidity. We test this hypothesis by examining growth-related changes in limb bone structure in two primate taxa that differ in ontogenetic patterns of joint posture. MATERIALS AND METHODS: Knee and elbow angles of adult and immature vervets (Chlorocebus aethiops, n = 16) were compared to published data for baboons (Papio hamadryas ursinus, n = 33, Patel et al., ). Ontogenetic changes in ratios of A-P/M-L bending rigidity in the femur and humerus were compared in skeletal samples (C. aethiops, n = 28; P. cynocephalus, n = 39). Size changes were assessed with linear regression, and age group differences tested with ANOVA. RESULTS: Only the knee of baboons shows significant postural change, becoming more extended with age and mass. A-P/M-L bending rigidity of the femur decreases during ontogeny in immature and adult female baboons only. Trends in the humerus are less marked. Adult male baboons have higher A-P/M-L bending rigidity of the femur than females. CONCLUSIONS: The hypothesized relationship between more extended joints and reduced A-P/M-L bending rigidity is supported by our results for immature and adult female baboon hind limbs, and the lack of significant age changes in either parameter in forelimbs and vervets. Adult males of both species depart from general ontogenetic trends, possibly due to socially mediated behavioral differences between sexes. Am J Phys Anthropol 161:72-83, 2016. © 2016 Wiley Periodicals, Inc.


Assuntos
Chlorocebus aethiops/anatomia & histologia , Membro Anterior/anatomia & histologia , Membro Posterior/anatomia & histologia , Articulações/anatomia & histologia , Papio/anatomia & histologia , Anatomia Transversal , Animais , Antropologia Física , Feminino , Masculino , Postura/fisiologia , Gravação em Vídeo
17.
J Hum Evol ; 94: 134-45, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27178465

RESUMO

Hybridization is increasingly proving to be an important force shaping human evolution. Comparisons of both ancient and modern genomes have provided support for a complex evolutionary scenario over the past million years, with evidence for multiple incidents of gene exchange. However, to date, genetic evidence is still limited in its ability to pinpoint the precise time and place of ancient admixture. For that we must rely on evidence of admixture from the skeleton. The research presented here builds on previous work on the crania of baboon hybrids, focusing on the nasal cavity of olive baboons, yellow baboons, and first generation (F1) hybrids. The nasal cavity is a particularly important anatomical region for study, given the clear differentiation of this feature in Neanderthals relative to their contemporaries, and therefore it is a feature that will likely differ in a distinctive manner in hybrids of these taxa. Metric data consist of 45 linear, area, and volume measurements taken from CT scans of known-pedigree baboon crania. Results indicate that there is clear evidence for differences among the nasal cavities of the parental taxa and their F1 hybrids, including a greater degree of sexual dimorphism in the hybrids. There is also some evidence for transgressive phenotypes in individual F1 animals. The greatest amount of shape variation occurs in the anterior bony cavity, the choana, and the mid-nasopharynx. Extrapolating our results to the fossil record, we would expect F1 hybrid fossils to have larger nasal cavities, on average, than either parental taxon, with overall nasal cavity shape showing the most profound changes in regions that are distinct between the parental taxa (e.g., anterior nasal cavity). We also expect size and shape differences to be more pronounced in male F1 hybrids than in females. Because of pronounced anterior nasal cavity differences between Neanderthals and their contemporaries, we suggest that this model might be effective for examining the fossil record of late Pleistocene contact.


Assuntos
Fósseis/anatomia & histologia , Hominidae/anatomia & histologia , Hibridização Genética , Cavidade Nasal/anatomia & histologia , Papio/anatomia & histologia , Animais , Antropologia Física , Evolução Biológica , Feminino , Humanos , Masculino , Papio/genética , Fenótipo
18.
Neuroimage ; 132: 526-533, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26975558

RESUMO

The baboon (Papio) brain is a remarkable model for investigating the brain. The current work aimed at creating a population-average baboon (Papio anubis) brain template and its left/right hemisphere symmetric version from a large sample of T1-weighted magnetic resonance images collected from 89 individuals. Averaging the prior probability maps output during the segmentation of each individual also produced the first baboon brain tissue probability maps for gray matter, white matter and cerebrospinal fluid. The templates and the tissue probability maps were created using state-of-the-art, freely available software tools and are being made freely and publicly available: http://www.nitrc.org/projects/haiko89/ or http://lpc.univ-amu.fr/spip.php?article589. It is hoped that these images will aid neuroimaging research of the baboon by, for example, providing a modern, high quality normalization target and accompanying standardized coordinate system as well as probabilistic priors that can be used during tissue segmentation.


Assuntos
Atlas como Assunto , Mapeamento Encefálico/métodos , Encéfalo/anatomia & histologia , Papio/anatomia & histologia , Animais , Feminino , Processamento de Imagem Assistida por Computador , Disseminação de Informação , Imageamento por Ressonância Magnética , Masculino , Software
19.
PLoS One ; 10(8): e0133361, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26287673

RESUMO

A new partial cranium (UW 88-886) of the Plio-Pleistocene baboon Papio angusticeps from Malapa is identified, described and discussed. UW 88-886 represents the only non-hominin primate yet recovered from Malapa and is important both in the context of baboon evolution as well as South African hominin site biochronology. The new specimen may represent the first appearance of modern baboon anatomy and coincides almost perfectly with molecular divergence date estimates for the origin of the modern P. hamadryas radiation. The fact that the Malapa specimen is dated between ~2.026-2.36 million years ago (Ma) also has implications for the biochronology of other South African Plio-Pleistocene sites where P. angusticeps is found.


Assuntos
Hominidae/anatomia & histologia , Papio hamadryas/anatomia & histologia , Papio/anatomia & histologia , Crânio/anatomia & histologia , Animais , Evolução Biológica , Fósseis/anatomia & histologia , Cabeça/anatomia & histologia , África do Sul
20.
Vis Neurosci ; 32: E006, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26241195

RESUMO

The goals of these experiments were to describe the morphology and synaptic connections of amacrine cells in the baboon retina that contain immunoreactive vesicular glutamate transporter 3 (vGluT3). These amacrine cells had the morphology characteristic of knotty bistratified type 1 cells, and their dendrites formed two plexuses on either side of the center of the inner plexiform layer. The primary dendrites received large synapses from amacrine cells, and the higher-order dendrites were both pre- and postsynaptic to other amacrine cells. Based on light microscopic immunolabeling results, these include AII cells and starburst cells, but not the polyaxonal amacrine cells tracer-coupled to ON parasol ganglion cells. The vGluT3 cells received input from ON bipolar cells at ribbon synapses and made synapses onto OFF bipolar cells, including the diffuse DB3a type. Many synapses from vGluT3 cells onto retinal ganglion cells were observed in both plexuses. At synapses where vGluT3 cells were presynaptic, two types of postsynaptic densities were observed; there were relatively thin ones characteristic of inhibitory synapses and relatively thick ones characteristic of excitatory synapses. In the light microscopic experiments with Neurobiotin-injected ganglion cells, vGluT3 cells made contacts with midget and parasol ganglion cells, including both ON and OFF types. Puncta containing immunoreactive gephyrin, an inhibitory synapse marker, were found at appositions between vGluT3 cells and each of the four types of labeled ganglion cells. The vGluT3 cells did not have detectable levels of immunoreactive γ-aminobutyric acid (GABA) or immunoreactive glycine transporter 1. Thus, the vGluT3 cells would be expected to have ON responses to light and make synapses onto neurons in both the ON and the OFF pathways. Taken with previous results, these findings suggest that vGluT3 cells release glycine at some of their output synapses and glutamate at others.


Assuntos
Células Amácrinas/metabolismo , Papio/anatomia & histologia , Retina/citologia , Sinapses/fisiologia , Proteínas Vesiculares de Transporte de Glutamato/metabolismo , Células Amácrinas/ultraestrutura , Animais , Biotina/análogos & derivados , Biotina/metabolismo , Calbindinas/metabolismo , Colina O-Acetiltransferase/metabolismo , Dendritos/ultraestrutura , Microscopia Confocal , Microscopia Imunoeletrônica , Rede Nervosa/metabolismo , Rede Nervosa/ultraestrutura , Sinapses/ultraestrutura , Proteínas Vesiculares de Transporte de Glutamato/ultraestrutura , Vias Visuais/fisiologia , Ácido gama-Aminobutírico/metabolismo
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