1
|
Drummond-Clarke RC, Kivell TL, Sarringhaus L, Stewart FA, Piel AK. Sex differences in positional behavior of chimpanzees (Pan troglodytes schweinfurthii) living in the dry and open habitat of Issa Valley, Tanzania. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024:e25007. [PMID: 39056239 DOI: 10.1002/ajpa.25007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Revised: 06/20/2024] [Accepted: 07/09/2024] [Indexed: 07/28/2024]
Abstract
OBJECTIVES Many early fossil hominins are associated with savanna-mosaic paleohabitats, and high sexual dimorphism that may reflect differences in positional behavior between sexes. However, reconstructions of hominin behavior and the selective pressures they faced in an open habitat are limited by a lack of studies of extant apes living in contemporary, analogous habitats. Here, we describe adult chimpanzee positional behavior in the savanna-mosaic habitat of the Issa Valley, Tanzania, to test whether Issa chimpanzees show larger sex-differences in positional behavior than their forest-dwelling counterparts. MATERIALS AND METHODS We quantified and compared adult locomotor and postural behavior across sexes (6 females, 7 males) in the riparian forest (closed) and miombo woodland (open) vegetation types at Issa Valley (13,743 focal observations). We then compared our results to published data of chimpanzee communities living in more forested habitats. RESULTS Issa females and males both spent less time arboreally in open vegetation and showed similar locomotor and postural behavior on the same substrates, notably using a high level of suspensory locomotion when arboreal. Females were, however, more arboreal than males during locomotor behavior, as well as compared with females from other communities. Issa males behaved similarly to males from other communities. CONCLUSION Results suggest that open habitats do not elicit less arboreal behaviors in either sex, and may even select for suspensory locomotion to effectively navigate an open canopy. An open habitat may, however, increase sex differences in positional behavior by driving female arboreality. We suggest this is because of higher energetic demands and predator pressures associated with open vegetation, which are likely exaggerated for reproducing females. These results have implications for the interpretation of how sexual dimorphism may influence reconstructions of hominin positional behavior.
Collapse
Affiliation(s)
| | - Tracy L Kivell
- Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Centre for the Exploration of the Deep Human Journey, University of the Witwatersrand, Johannesburg, South Africa
| | | | - Fiona A Stewart
- Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Anthropology, University College London, London, UK
| | - Alex K Piel
- Department of Human Origins, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany
- Department of Anthropology, University College London, London, UK
| |
Collapse
|
2
|
O'Neill MC, Nagano A, Umberger BR. A three-dimensional musculoskeletal model of the pelvis and lower limb of Australopithecus afarensis. AMERICAN JOURNAL OF BIOLOGICAL ANTHROPOLOGY 2024; 183:e24845. [PMID: 37671481 DOI: 10.1002/ajpa.24845] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 07/08/2023] [Accepted: 08/17/2023] [Indexed: 09/07/2023]
Abstract
OBJECTIVES Musculoskeletal modeling is a powerful approach for studying the biomechanics and energetics of locomotion. Australopithecus (A.) afarensis is among the best represented fossil hominins and provides critical information about the evolution of musculoskeletal design and locomotion in the hominin lineage. Here, we develop and evaluate a three-dimensional (3-D) musculoskeletal model of the pelvis and lower limb of A. afarensis for predicting muscle-tendon moment arms and moment-generating capacities across lower limb joint positions encompassing a range of locomotor behaviors. MATERIALS AND METHODS A 3-D musculoskeletal model of an adult A. afarensis pelvis and lower limb was developed based primarily on the A.L. 288-1 partial skeleton. The model includes geometric representations of bones, joints and 35 muscle-tendon units represented using 43 Hill-type muscle models. Two muscle parameter datasets were created from human and chimpanzee sources. 3-D muscle-tendon moment arms and isometric joint moments were predicted over a wide range of joint positions. RESULTS Predicted muscle-tendon moment arms generally agreed with skeletal metrics, and corresponded with human and chimpanzee models. Human and chimpanzee-based muscle parameterizations were similar, with some differences in maximum isometric force-producing capabilities. The model is amenable to size scaling from A.L. 288-1 to the larger KSD-VP-1/1, which subsumes a wide range of size variation in A. afarensis. DISCUSSION This model represents an important tool for studying the integrated function of the neuromusculoskeletal systems in A. afarensis. It is similar to current human and chimpanzee models in musculoskeletal detail, and will permit direct, comparative 3-D simulation studies.
Collapse
Affiliation(s)
- Matthew C O'Neill
- Department of Anatomy, Midwestern University, Glendale, Arizona, USA
| | - Akinori Nagano
- Faculty of Sport and Health Science, Ritsumeikan University, Kusatsu, Shiga, Japan
| | - Brian R Umberger
- School of Kinesiology, University of Michigan, Ann Arbor, Michigan, USA
| |
Collapse
|
3
|
Human and African ape myosin heavy chain content and the evolution of hominin skeletal muscle. Comp Biochem Physiol A Mol Integr Physiol 2023; 281:111415. [PMID: 36931425 DOI: 10.1016/j.cbpa.2023.111415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 03/13/2023] [Accepted: 03/13/2023] [Indexed: 03/17/2023]
Abstract
Humans are unique among terrestrial mammals in our manner of walking and running, reflecting 7 to 8 Ma of musculoskeletal evolution since diverging with the genus Pan. One component of this is a shift in our skeletal muscle biology towards a predominance of myosin heavy chain (MyHC) I isoforms (i.e. slow fibers) across our pelvis and lower limbs, which distinguishes us from chimpanzees. Here, new MyHC data from 35 pelvis and hind limb muscles of a Western gorilla (Gorilla gorilla) are presented. These data are combined with a similar chimpanzee dataset to assess the MyHC I content of humans in comparison to African apes (chimpanzees and gorillas) and other terrestrial mammals. The responsiveness of human skeletal muscle to behavioral interventions is also compared to the human-African ape differential. Humans are distinct from African apes and among a small group of terrestrial mammals whose pelvis and hind/lower limb muscle is slow fiber dominant, on average. Behavioral interventions, including immobilization, bed rest, spaceflight and exercise, can induce modest decreases and increases in human MyHC I content (i.e. -9.3% to 2.3%, n = 2033 subjects), but these shifts are much smaller than the mean human-African ape differential (i.e. 31%). Taken together, these results indicate muscle fiber content is likely an evolvable trait under selection in the hominin lineage. As such, we highlight potential targets of selection in the genome (e.g. regions that regulate MyHC content) that may play an important role in hominin skeletal muscle evolution.
Collapse
|
4
|
Pampush JD, Fuselier EJ, Yapuncich GS. Using BayesModelS to provide Bayesian- and phylogenetically-informed primate body mass predictions. J Hum Evol 2021; 161:103077. [PMID: 34688978 DOI: 10.1016/j.jhevol.2021.103077] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Revised: 09/01/2021] [Accepted: 09/01/2021] [Indexed: 10/20/2022]
Abstract
An accurate prediction of the body mass of an extinct species can greatly inform the reconstruction of that species' ecology. Therefore, paleontologists frequently predict the body mass of extinct taxa from fossilized materials, particularly dental dimensions. Body mass prediction has traditionally been performed in a frequentist statistical framework, and accounting for phylogenetic relationships while calibrating prediction models has only recently become more commonplace. In this article, we apply BayesModelS-a phylogenetically informed Bayesian prediction method-to predict body mass in a sample of 49 euarchontan species (24 strepsirrhines, 20 platyrrhines, 3 tarsiids, 1 dermopteran, and 1 scandentian) and compare this approach's body mass prediction accuracy with other commonly used techniques, namely ordinary least squares, phylogenetic generalized least squares, and phylogenetic independent contrasts (PICs). When predicting the body masses of extant euarchontans from dental and postcranial variables, BayesModelS and PICs have substantially higher predictive accuracy than ordinary least squares and phylogenetic generalized least squares. The improved performances of BayesModelS and PIC are most evident for dentally derived body mass proxies or when body mass proxies have high degrees of phylogenetic covariance. Predicted values generated by BayesModelS and PIC methods also show less variance across body mass proxies when applied to the Eocene adapiform Notharctus tenebrosus. These more explicitly phylogenetically based methods should prove useful for predicting body mass in a paleontological context, and we provide executive scripts for both BayesModelS and PIC to increase ease of application.
Collapse
Affiliation(s)
- James D Pampush
- Department of Exercise Science, High Point University, High Point, NC 27260, USA; Department of Physician Assistant Studies, High Point University, High Point, NC 27260, USA.
| | - Edward J Fuselier
- Department of Mathematical Sciences, High Point University, High Point, NC 27260, USA
| | - Gabriel S Yapuncich
- Department of Evolutionary Anthropology, Duke University, Durham, NC 27708, USA; Medical Education Administration, Duke University School of Medicine, Durham, NC 27710, USA
| |
Collapse
|
5
|
A chimpanzee enamel-diet δ 13C enrichment factor and a refined enamel sampling strategy: Implications for dietary reconstructions. J Hum Evol 2021; 159:103062. [PMID: 34536662 DOI: 10.1016/j.jhevol.2021.103062] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 08/01/2021] [Accepted: 08/01/2021] [Indexed: 11/24/2022]
Abstract
Reconstructing diets from stable carbon isotopic signals in enamel bioapatite requires the application of a δ13C enamel-diet enrichment factor, or the isotopic offset between diet and enamel, which has not been empirically determined for any primate. In this study, an enamel-diet enrichment factor (ε∗enamel-diet) of 11.8 ± 0.3‰ is calculated for chimpanzees (Pan troglodytes) at Ngogo in Kibale National Park, Uganda, based on a comprehensive isotopic assessment of previously analyzed dietary plant data and new isotopic analyses of enamel apatite. Different enamel sampling methods are evaluated to determine the potential influence of weaning on isotopic enamel values and dietary interpretations. The new chimpanzee enrichment factor and a sampling strategy that excludes teeth that formed before weaning completion are applied to all known chimpanzee δ13Cenamel data, either previously published or newly derived in this study, resulting in a dietary range of almost 6‰ across all chimpanzees sampled. This new chimpanzee enamel-diet enrichment factor is then used to reassess dietary reconstructions of 12 fossil hominin species whose isotopic enamel signatures have been determined. Results reveal hominin diets that are isotopically more positive than previously reconstructed, highlighting the widespread contribution of 13C-enriched C4/crassulacean acid metabolism (CAM) resources in fossil hominin diets and emphasizing the broad use of these resources during human evolution. These findings stress the importance of ascertaining and employing an appropriate enrichment factor for dietary reconstructions of specific taxa as well as standardizing the sampling protocol for tooth enamel in isotopic paleodietary reconstructions.
Collapse
|
6
|
Divergence-time estimates for hominins provide insight into encephalization and body mass trends in human evolution. Nat Ecol Evol 2021; 5:808-819. [PMID: 33795855 DOI: 10.1038/s41559-021-01431-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 02/25/2021] [Indexed: 12/18/2022]
Abstract
Quantifying speciation times during human evolution is fundamental as it provides a timescale to test for the correlation between key evolutionary transitions and extrinsic factors such as climatic or environmental change. Here, we applied a total evidence dating approach to a hominin phylogeny to estimate divergence times under different topological hypotheses. The time-scaled phylogenies were subsequently used to perform ancestral state reconstructions of body mass and phylogenetic encephalization quotient (PEQ). Our divergence-time estimates are consistent with other recent studies that analysed extant species. We show that the origin of the genus Homo probably occurred between 4.30 and 2.56 million years ago. The ancestral state reconstructions show a general trend towards a smaller body mass before the emergence of Homo, followed by a trend towards a greater body mass. PEQ estimations display a general trend of gradual but accelerating encephalization evolution. The obtained results provide a rigorous temporal framework for human evolution.
Collapse
|
7
|
Prang TC, Ramirez K, Grabowski M, Williams SA. Ardipithecus hand provides evidence that humans and chimpanzees evolved from an ancestor with suspensory adaptations. SCIENCE ADVANCES 2021; 7:eabf2474. [PMID: 33627435 PMCID: PMC7904256 DOI: 10.1126/sciadv.abf2474] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2020] [Accepted: 01/12/2021] [Indexed: 05/08/2023]
Abstract
The morphology and positional behavior of the last common ancestor of humans and chimpanzees are critical for understanding the evolution of bipedalism. Early 20th century anatomical research supported the view that humans evolved from a suspensory ancestor bearing some resemblance to apes. However, the hand of the 4.4-million-year-old hominin Ardipithecus ramidus purportedly provides evidence that the hominin hand was derived from a more generalized form. Here, we use morphometric and phylogenetic comparative methods to show that Ardipithecus retains suspensory adapted hand morphologies shared with chimpanzees and bonobos. We identify an evolutionary shift in hand morphology between Ardipithecus and Australopithecus that renews questions about the coevolution of hominin manipulative capabilities and obligate bipedalism initially proposed by Darwin. Overall, our results suggest that early hominins evolved from an ancestor with a varied positional repertoire including suspension and vertical climbing, directly affecting the viable range of hypotheses for the origin of our lineage.
Collapse
Affiliation(s)
- Thomas C Prang
- Department of Anthropology, Texas A&M University, College Station, TX 77843, USA.
| | - Kristen Ramirez
- New York Consortium in Evolutionary Primatology, New York, NY 10024, USA
- Department of Anthropology, CUNY Graduate Center, New York, NY 10016, USA
- Office of Medical Education, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Mark Grabowski
- Research Centre in Evolutionary Anthropology and Palaeoecology, Liverpool John Moores University, Liverpool, UK
- Centre for Ecology and Evolutionary Synthesis, Department of Biosciences, University of Oslo, Oslo, Norway
| | - Scott A Williams
- New York Consortium in Evolutionary Primatology, New York, NY 10024, USA
- Center for the Study of Human Origins, Department of Anthropology, New York University, New York, NY 10003, USA
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Wits 2050, Johannesburg, South Africa
| |
Collapse
|
8
|
Chaney ME, Ruiz CA, Meindl RS, Lovejoy CO. The foot of the human-chimpanzee last common ancestor was not African ape-like: A response to Prang (2019). J Hum Evol 2021; 164:102940. [PMID: 33441261 DOI: 10.1016/j.jhevol.2020.102940] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 12/14/2020] [Accepted: 12/14/2020] [Indexed: 10/22/2022]
Affiliation(s)
- Morgan E Chaney
- Department of Anthropology & School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA.
| | - Cody A Ruiz
- Department of Anthropology & School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - Richard S Meindl
- Department of Anthropology & School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| | - C Owen Lovejoy
- Department of Anthropology & School of Biomedical Sciences, Kent State University, Kent, OH, 44242, USA
| |
Collapse
|
9
|
Macchiarelli R, Bergeret-Medina A, Marchi D, Wood B. Nature and relationships of Sahelanthropus tchadensis. J Hum Evol 2020; 149:102898. [PMID: 33142154 DOI: 10.1016/j.jhevol.2020.102898] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 09/30/2020] [Accepted: 09/30/2020] [Indexed: 02/08/2023]
Abstract
A partial left femur (TM 266-01-063) was recovered in July 2001 at Toros-Menalla, Chad, at the same fossiliferous location as the late Miocene holotype of Sahelanthropus tchadensis (the cranium TM 266-01-060-1). It was recognized as a probable primate femur in 2004 when one of the authors was undertaking a taphonomic survey of the fossil assemblages from Toros-Menalla. We are confident the TM 266 femoral shaft belongs to a hominid. It could sample a hominid hitherto unrepresented at Toros-Menalla, but a more parsimonious working hypothesis is that it belongs to S. tchadensis. The differences between TM 266 and the late Miocene Orrorin tugenensis partial femur BAR 1002'00, from Kenya, are consistent with maintaining at least a species-level distinction between S. tchadensis and O. tugenensis. The results of our preliminary functional analysis suggest the TM 266 femoral shaft belongs to an individual that was not habitually bipedal, something that should be taken into account when considering the relationships of S. tchadensis. The circumstances of its discovery should encourage researchers to check to see whether there is more postcranial evidence of S. tchadensis among the fossils recovered from Toros-Menalla.
Collapse
Affiliation(s)
- Roberto Macchiarelli
- Unité de Formation Géosciences, Université de Poitiers, 86073, Poitiers, France; Département Homme & Environnement, UMR 7194 CNRS, Muséum national d'Histoire naturelle, 75116, Paris, France.
| | | | - Damiano Marchi
- Department of Biology, University of Pisa, 56126, Pisa, Italy; Evolutionary Studies Institute and Centre for Excellence in PalaeoSciences, University of the Witwatersrand, Wits, 2050, South Africa
| | - Bernard Wood
- Center for the Advanced Study of Human Paleobiology and Department of Anthropology, George Washington University, Washington, DC, 20052, USA
| |
Collapse
|
10
|
Yaxley KJ, Foley RA. Reconstructing the ancestral phenotypes of great apes and humans (Homininae) using subspecies-level phylogenies. Biol J Linn Soc Lond 2019. [DOI: 10.1093/biolinnean/blz140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Abstract
Owing to their close affinity, the African great apes are of interest in the study of human evolution. Although numerous researchers have described the ancestors we share with these species with reference to extant great apes, few have done so with phylogenetic comparative methods. One obstacle to the application of these techniques is the within-species phenotypic variation found in this group. Here, we leverage this variation, modelling common ancestors using ancestral state reconstructions (ASRs) with reference to subspecies-level trait data. A subspecies-level phylogeny of the African great apes and humans was estimated from full-genome mitochondrial DNA sequences and used to implement ASRs for 14 continuous traits known to vary between great ape subspecies. Although the inclusion of within-species phenotypic variation increased the phylogenetic signal for our traits and improved the performance of our ASRs, whether this was done through the inclusion of subspecies phylogeny or through the use of existing methods made little difference. Our ASRs corroborate previous findings that the last common ancestor of humans, chimpanzees and bonobos was a chimp-like animal, but also suggest that the last common ancestor of humans, chimpanzees, bonobos and gorillas was an animal unlike any extant African great ape.
Collapse
Affiliation(s)
| | - Robert A Foley
- Leverhulme Centre for Human Evolutionary Studies, University of Cambridge, Cambridge, UK
| |
Collapse
|
11
|
Cunningham DL, Rogers MV, Wescott DJ, McCarthy RC. Reevaluation of the body mass estimate for the KNM-ER 5428 Homo erectus talus. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 2019; 170:148-155. [PMID: 31268179 DOI: 10.1002/ajpa.23898] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2018] [Revised: 06/17/2019] [Accepted: 06/19/2019] [Indexed: 11/09/2022]
Abstract
OBJECTIVES In this study, we reexamined the body mass estimate for the Homo erectus specimen KNM-ER 5428 based on talus dimensions. Previous estimates of >90 kg for this fossil are large in comparison to body mass estimates for other H. erectus specimens. MATERIALS AND METHODS The study sample consisted of tali and femora of 132 modern cadaver males from a documented body mass skeletal collection. We recorded the talus trochlear mediolateral (TTML) breadth and femoral head diameter (FHD) for each modern human specimen, and obtained KNM-ER 5428's TTML values from the literature. We developed regression formulae based on TTML using the body mass estimated from FHD for the entire human sample and for known body masses from a normal-BMI subsample, and then used these formulae to calculate body mass for KNM-ER 5428. In addition, we examined the range of body masses for individuals with TTML measurements comparable to KNM-ER 5428. RESULTS The body masses of normal-BMI individuals with a TTML ≥32.3 mm (the smaller of the two fossil measurements from the literature) ranged between 60.3 and 86.2 kg and averaged 72.3 kg. The body masses of normal-BMI individuals with a TTML ≥33.7 mm (the larger measurement) ranged between 63.5 and 86.2 kg with a mean of 73.6 kg. The correlations between TTML and body mass are moderate. Revised body mass point estimates for KNM-ER 5428 ranged between 69.2 and 81.6 kg based on TTML, and average 70.5 and 76.0 kg. DISCUSSION Results suggest previously published body mass estimates of KNM-ER 5428's are too large. Its body mass was likely between 70 and 76 kg rather than >90 kg.
Collapse
Affiliation(s)
| | - Melinda V Rogers
- Department of Anthropology, Texas State University, San Marcos, Texas
| | - Daniel J Wescott
- Department of Anthropology, Texas State University, San Marcos, Texas
| | - Robert C McCarthy
- Department of Biological Sciences, Benedictine University, Lisle, Illinois
| |
Collapse
|
12
|
Simpson SW, Levin NE, Quade J, Rogers MJ, Semaw S. Ardipithecus ramidus postcrania from the Gona Project area, Afar Regional State, Ethiopia. J Hum Evol 2019; 129:1-45. [DOI: 10.1016/j.jhevol.2018.12.005] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 11/26/2018] [Accepted: 12/05/2018] [Indexed: 11/30/2022]
|