Virtual Ancestor Reconstruction: revealing the ancestor of modern humans and Neandertals

The timing and geographic origin of the common ancestor of modern humans and Neandertals remain controversial. A poor Pleistocene hominin fossil record, and the evolutionary complexities introduced by dispersals and regionalisation of lineages have fuelled taxonomic uncertainty, while new ancient genomic data have raised completely new questions. Here, we use maximum likelihood and 3D geometric morphometric methods to predict possible morphologies of the last common ancestor of modern humans and Neandertals from a simplified fully-resolved phylogeny. We describe the fully-rendered 3-dimensional shapes of the predicted ancestors of humans and Neandertals, and assess their similarity to individual fossils or population of fossils of Pleistocene age. Our results support models of an Afro-European ancestral population in the Middle Pleistocene (H. heidelbergensis sensu lato) and further predict an African origin for this ancestral population.This study was partially funded by the Fyssen Foundation, and an Advanced ERC Award (IN-AFRICA Project). For permission to study specimens in their care we thank directors and curators of the following institutions: Musée de l’Homme (Paris, France); Institut de Paléontologie Humaine (Paris, France); Staatliches Museum für Naturkunde (Stuttgart, Germany); Aristotle University of Thessaloniki (Thessaloniki, Greece); Soprintendenza Archeologia del Lazio, Servizio di Antropologia (Rome, Italy); Museo di Antropologia G. Sergi (Sapienza Università di Roma, Italy); Museo preistorico-etonografico ‘L. Pigorini’ (Rome, Italy); National Museums of Kenya (Nairobi, Kenya); National Museum (Bloemfontein, Republic of South Africa); Natural History Museum (London, UK); Duckworth Collection (Cambridge, UK). We thank F. Lahr and F. Rivera for assistance with CT-scanning and E. Delson, R. Foley, L. Puymerail and A. Froment for help and ideas. Finally, we thank M. Plavcan, D. Polly, the Associate Editor and two anonymous reviewers for valuable comments and criticisms of earlier drafts which contributed to the improvement of this study.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.jhevol.2015.11.00