An analysis of fossils suggests changes in the shape of the braincase during human evolution were linked to alterations in the face, rather than changes in the brain itself
The physical transformation of the human cranium over the past 160,000 years was probably driven by alterations in the face resulting from diet and lifestyle changes, not from the evolution of the brain itself as previously thought, a study has found.
The cranium, or braincase, of early modern humans dating back 200,000 years isn’t much different in size from those today, but has a significantly different shape, suggesting that the brain has become rounder over time.
The leading hypothesis is that changes in behaviour, such as the development of tools and art, caused the shape of the Homo sapiens brain to change and, in turn, the skull that protects it.
But fossil evidence is scarce and there are many interacting forces at play. It is simple for a skull with a large face to house a large brain, for example, but a small face complicates matters.