Cancer-causing human papillomaviruses (HPVs) diverged from their most recent common ancestors approximately half a million years ago, roughly coinciding with the timing of the split between archaic Neanderthals and modern Homo sapiens, according to a study published November 1 in the open-access journal PLOS Pathogens by Zigui Chen of the Chinese University of Hong Kong, Robert Burk of the Albert Einstein College of Medicine, and colleagues.