The role of hybridisation in hominin morphology

University of Liverpool Evolutionary Anthropology Webinar Series: Thursday 4th of November 2021
Dr Laura Buck, Liverpool John Moores University, on "The role of hybridisation in hominin morphology"
Abstract: Recent advances in genetics have shown that hybridisation occurred during human evolution, yet its morphological impact remains underexplored. Ancient DNA is a powerful tool but given the conditions required for its preservation, it is best combined with fossil morphology. Studies of non-human primates have suggested a signature hybrid morphology including extreme size, high levels of variation, and markers of developmental instability, but how phylogenetic distance and admixture proportion affect these characteristics is unknown. Non-mammalian studies suggest extreme morphotypes are more likely in early generation hybrids and with greater divergence between parents. To understand the hominin fossil record, we must study admixture in taxa that approximate hominin hybridisation as closely as possible. Here, we use macaque proxies (Chinese and Indian Macaca mulatta) with comparable divergence time (in generations) to Homo sapiens / Neanderthals. Our sample is large, multigenerational and of known hybridity. We focus here on the pelvis, which has potential fitness implications for hybrids if successful parturition is compromised. We find no individuals showing extreme morphology. Instead, we see a significant, but weak, hybrid signal that is proportional to the relatively small morphological difference between the parent taxa. The similarity in shape between the full-bred macaques is in contrast to that between Neanderthals and H. sapiens, despite comparable phylogenetic divergence between both hybridising pairs. The greater disparity between the hominins may owe something to adaptation their respective environments, but may also reflect the extent of cultural buffering in hominins, which allows for greater neutral evolution. This work highlights one of the fundamental ways in which hominins may differ from our primate relations and provides a way forward for unpicking the effects of hybridisation on hominin morphology.
Hosted by Matt Grove, Lecturer in Evolutionary Anthropology at the University of Liverpool.
For more information about the programme, find us on Twitter at @LivUni_EvoAnth or email us at [e-mail].
Disclaimer: The information contained in the multimedia content (“Video Content”) posted represents the views and opinions of the original creators of such Video Content and does not necessarily represent the views or opinions of the Department of Archaeology, Classics and Egyptology, University of Liverpool. The mere appearance of Video Content on the Site does not constitute an endorsement by the Department or its affiliates of such Video Content. The Video Content has been made available for informational and educational purposes only. The Department does not make any representation or warranties with respect to the accuracy, applicability, fitness or completeness of the Video Content, nor of the performance, effectiveness or applicability of any sites listed or linked to in any Video Content.