26.10.2021 Marcia Ponce de León and Christoph Zollikofer

Inferring brain and cognitive evolution from fossil human endocasts

 

When and how language emerged during our evolutionary history is still shrouded in mystery. In this talk, we examine the fossil neurocranial evidence for language-related capabilities since the beginnings of our own genus Homo. The internal surface of the braincase – the so-called endocast – preserves imprints of cerebral convolutions and surrounding vascular and neurocranial structures. Tracking changes in fossil endocast morphology over the past two million years, and comparing fossil data with data from living humans and great apes permits inferences on the actual course of brain reorganization, and its relation to language evolution. We argue that key changes in frontal cerebral lobe areas involved in language production appeared comparatively late – between 1.7 and 1.5 million years ago, well after Homo first left Africa, and after the emergence of complex socio-cognitive capabilities.