Larger brain, smaller face: Human evolution took a different course than previously thought

A new study, published July 6, 2026, in the journal Nature Communications, suggests that two of the best-known trends in human evolution—brain growth and the reduction in the size of the face and jaw—may be far less attributable to directed natural selection than scientists have long assumed.

Instead, the findings by researchers at the University of Tennessee-Knoxville and the Senckenberg Centre for Human Evolution and Palaeoenvironment (SHEP) at the University of Tübingen point to a slower and presumably more limited evolutionary process than the traditional textbook portrayal suggests. ...