In saliva, clues to a ‘ghost’ species of ancient human

In saliva, scientists have found hints that a ‘ghost’ species of archaic humans may have contributed genetic material to ancestors of people living in sub-Saharan Africa today. The research adds to a growing body of evidence suggesting that sexual rendezvous between different archaic human species may not have been unusual.
Strange & Offbeat: Fossils & Ruins News — ScienceDaily