Neanderthals and Denisovans interbred with the ancestors of modern humans, leaving recognizable traces in our DNA. Evidence now suggests that modern humans also interbred with two much older, unidentified ancestral groups. Hidden within the genomes of people alive today are fragments of DNA from two unidentified human ancestors. Researchers at UC Berkeley traced these genetic [...]from SciTechDaily https://ift.tt/uqn3yTR
