Tourists in front of the Denisova Cave in the Altai Mountains in Siberia, where "X woman" was found. According to recent genetic studies, modern humans may have mated with "at least two groups" of ancient humans: Neanderthals and Denisovans. Genetic study indicates approximately 4% of the DNA of non-African modern humans is the same as that found in Neanderthals, suggesting interbreeding.
19 Pieces Of Non-Human DNA Found In Human Genome. IFLScience Search Health and Medicine 19 Pieces Of Non-Human DNA Found In Human Genome. Eight percent of your DNA is alien, in that it’s made up of non-human, viral fragments.