At some point in our evolutionary history, our Homo sapiens ancestors had sex with Neanderthals. Those cross-species trysts are the reason why almost everyone has a little bit of Neanderthal DNA in them today. Now, a new study published in the journal Molecular Biology and Evolution suggests that in addition to genetic material, the ancient hominids may have given us a common sexually-transmitted infection: A version of the human papillomavirus (HPV) that also causes cervical and oral cancers.
The next time you fight off the flu, you might want to thank your ancestors for flirting with the Neanderthal down the way. According to a pair of new studies, interbreeding between several early human species may have given us a key ingredient in fighting disease.