Ancestry searches by DNA testing has become almost a game for many people, with discoveries of lost and unexpected lineage being sometimes surprising, sometimes shocking and sometimes a relief. How would you feel if your DNA test showed you and the native people of your country are the primary descendants of an extinct branch of Hominins that wasn’t even know just a few decades ago? That’s what some people in the Philippines are dealing with after a new study found that one particular ethnic group in that country carries more Denisovan DNA than even Papuan Highlanders, the previously accepted leaders in Denisovan DNA.
“Some groups, though, such as the Ayta Magbukon, minimally admixed with the more recent incoming migrants. For this reason, the Ayta Magbukon retained most of their inherited archaic tracts and were left with the highest level of Denisovan ancestry in the world."
One of the biggest surprises as DNA scientists and anthropologists acquire better tools and more DNA samples from modern humans to work with and more remains and DNA samples from archaic varieties of Homo is that Denisovans and Neanderthals lived at the same time as early Homo sapiens and they all seemed to have interbred before two branches became extinct. The search to trace early hominin migration, as well as determine how and why they became extinct, is greatly helped by studying ethnic groups who possess high concentrations of their DNA. The discovery of Denisovan bone fragments in Siberia and Tibet gave researchers the mitochondrial DNA needed to trace its presence in modern humans, which eventually identified Papuan Highlanders as their primary modern descendants. Maximilian Larena of Uppsala University led a team that studied DNA of Philippine residents to determine their relation to Denisovans, with the results published in the journal Current Biology. She says in a press release:
“We made this observation despite the fact that Philippine Negritos were recently admixed with East Asian-related groups—who carry little Denisovan ancestry, and which consequently diluted their levels of Denisovan ancestry. If we account for and masked away the East Asian-related ancestry in Philippine Negritos, their Denisovan ancestry can be up to 46 percent greater than that of Australians and Papuans."
The Philippine Negrito ethnic group contains over 30 smaller groups and one, the Ayta Magbukon, showed promise. However, the group also had a high concentration of East Asian DNA acquired from recent intermixing. Once that was factored out, their Densivon DNA concentration showed a level “∼30%–40% greater than that of Australians and Papuans—consistent with an independent admixture event into Negritos from Denisovans.” Throw in some DNA from Homo luzonensis, yet another archaic Homo discovered in the Philippines in 2019 and this study reveals that multiple archaic species inhabited the Philippines prior to the arrival of early Homo sapiens and they may have even been genetically related.
Besides the fact that this new discovery shows the Denisovans covered a greater geographic area than first thought, it strengthens the case that our own survival as a species depended on genetic traits we acquired from Neanderthals, Denisovans and probably other archaic humans. The inter-mixers survived – the non-mixers did not.
Anybody see a message for modern humans from the Denisovans?