Fossil hominin shoulders support an African ape-like last common ancestor of humans and chimpanzees
TLDR
It is proposed that the shoulder evolved gradually along a single morphocline, achieving modern human-like configuration and function within the genus Homo, consistent with a slow, progressive loss of arboreality and increased tool use throughout human evolution.Abstract:
Reconstructing the behavioral shifts that drove hominin evolution requires knowledge of the timing, magnitude, and direction of anatomical changes over the past ∼6–7 million years. These reconstructions depend on assumptions regarding the morphotype of the Homo–Pan last common ancestor (LCA). However, there is little consensus for the LCA, with proposed models ranging from African ape to orangutan or generalized Miocene ape-like. The ancestral state of the shoulder is of particular interest because it is functionally associated with important behavioral shifts in hominins, such as reduced arboreality, high-speed throwing, and tool use. However, previous morphometric analyses of both living and fossil taxa have yielded contradictory results. Here, we generated a 3D morphospace of ape and human scapular shape to plot evolutionary trajectories, predict ancestral morphologies, and directly test alternative evolutionary hypotheses using the hominin fossil evidence. We show that the most parsimonious model for the evolution of hominin shoulder shape starts with an African ape-like ancestral state. We propose that the shoulder evolved gradually along a single morphocline, achieving modern human-like configuration and function within the genus Homo. These data are consistent with a slow, progressive loss of arboreality and increased tool use throughout human evolution.read more
Citations
More filters
Journal ArticleDOI
A potential pitfall in studies of biological shape: Does size matter?
David Outomuro,Frank Johansson +1 more
TL;DR: This work assessed, for the first time and in a systematic manner, how often published studies that have applied GM consider the potential effects of allometry on shape, and reviewed the 300 most recent published papers that used GM for studying biological shape.
Journal ArticleDOI
Pitfalls reconstructing the last common ancestor of chimpanzees and humans.
TL;DR: The morphological nature of the last common ancestor (LCA) of chimpanzees/bonobos and humans is a fascinating topic in human evolution as discussed by the authors, but the hominoid fossil record of this time period is inadequate, prompting the use of novel methodological approaches to reconstruct the anatomy of this key ancestor.
Journal ArticleDOI
The evolution of the human trophic level during the Pleistocene.
TL;DR: In this paper, the authors reconstruct the trophic level (HTL) during the Pleistocene by reviewing evidence for the impact of the HTL on the biological, ecological, and behavioral systems derived from various existing studies.
Journal ArticleDOI
On The Evolution of The Sex Differences in Throwing: Throwing is a Male Adaptation in Humans
TL;DR: It is predicted that males, more than females, should display innate anatomical and behavioral traits associated with throwing, which contradict the view held by many commentators that socialization rather than innate sex differences in ability are primarily responsible for male throwing superiority.
Journal ArticleDOI
The African ape-like foot of Ardipithecus ramidus and its implications for the origin of bipedalism
TL;DR: It is shown that the foot of Ar.
References
More filters
Mesquite: a modular system for evolutionary analysis. Version 2.6
W. P. Maddison,D. R. Maddison +1 more
Journal ArticleDOI
Morphoj: an integrated software package for geometric morphometrics
TL;DR: The MorphoJ software offers an integrated and user‐friendly environment for standard multivariate analyses such as principal components, discriminant analysis and multivariate regression as well as specialized applications including phylogenetics, quantitative genetics and analyses of modularity in shape data.
Book
Geometric morphometrics for biologists: a primer
TL;DR: The second edition of "Geometric Morphometrics for Biologists" represents the current state of the art and adds new examples and summarizes recent literature, as well as provides an overview of new software and step-by-step guidance through details of carrying out the analyses.
Journal ArticleDOI
geomorph: an r package for the collection and analysis of geometric morphometric shape data
TL;DR: Geomorph as discussed by the authors is a software package for performing geometric morphometric shape analysis in the R statistical computing environment, where a set of shape variables are obtained from landmark coordinates following a Procrustes superimposition.
Journal ArticleDOI
3.3-million-year-old stone tools from Lomekwi 3, West Turkana, Kenya
Sonia Harmand,Jason Lewis,Craig S. Feibel,Christopher J. Lepre,Sandrine Prat,Arnaud Lenoble,Xavier Boës,Rhonda L. Quinn,Michael Brenet,Adrián Arroyo,Nick Taylor,Sophie Clément,Guillaume Daver,Jean-Phillip Brugal,Louise N. Leakey,Richard A. Mortlock,James D. Wright,Sammy Lokorodi,Christopher Kirwa,Dennis V. Kent,Hélène Roche +20 more
TL;DR: The discovery of Lomekwi 3 is reported, a 3.3-million-year-old archaeological site where in situ stone artefacts occur in spatiotemporal association with Pliocene hominin fossils in a wooded palaeoenvironment and the name ‘Lomekwian’ is proposed, which predates the Oldowan by 700,000 years and marks a new beginning to the known archaeological record.