Human evolution used to be depicted as a straight line, gradually progressing from an ape-like ancestor to modern Homo sapiens. But thanks to next-generation sequencing, findings in recent years have shown that it wasn’t quite so orderly. Now, a new study is reporting new details about the role of viruses in shaping evolution, in particular viral interactions between modern humans and Neanderthals.
I first thought, based on the headline, that maybe this would be about some sort of retrovirus-mediated horizontal gene transfer. But viruses as a source of selective pressure is interesting too, and probably has a more significant contribution to recent human evolution.
Indeed. Actually, there is some evidence that the CCR5 allele which provides HIV resistance was originally selected for because of smallpox. http://www.pnas.org/content/100/25/15276