Researchers at the prestigious University of California, Berkeley, have made a spectacular discovery: they identified stretches of DNA in the genomes of modern humans (source in German) that come from previously unknown ancestors. Earlier studies had already shown that modern humans interbred with Neanderthals and the so-called Denisovans and had joint offspring. A new study now suggests that there were at least two further, previously unknown human groups that also passed on DNA to our ancestors. RelatedAdvertisement AdvertisementAdvertisement AdvertisementOne of these previously unknown ancestors interbred in Africa with the forebears of modern humans more than 50,000 years ago. "However, it was previously unclear whether this unknown lineage occurs only in Africans and when this admixture happened.