James Pampush devoted five years and his Ph.D. dissertation to one question: Why do homo sapiens have chins, when all of our evolutionary relatives don't? He tells NPR's Robert Siegel about "the enduring puzzle of the human chin."

ncG1vNJzZmivp6x7r7zRZ6arn19nfXKCjmloaGppZIF3gJdyamtwYWTEqcWMnaZmoKWirq%2B%2FjKGYr51dmLWqutJmmGark56yr8DIrKtmnailuaK1zaxkraCVYrKvsNSroKefXaXCu8bLng%3D%3D