New research suggests that modern conditions may trace back to Neanderthal skull traits we share with our extinct cousins.

Dr. Phoebe Stubblefield, the director of the University of Florida’s C.A. Pound Human Identification Laboratory, said that she was not surprised to learn that a human skull had been listed for sale.

Troops of Mr. Storms killed and decapitated Mr. Lusinga in 1884, and his skull ended up in a box in the Brussels-based Institute for Natural Sciences, along with over 500 human remains taken from ...