Since their discovery just a few decades ago, the Denisovans have become a subject of heated discussion and debate. Being a subspecies of archaic humans, they are considered members of our constantly-growing family tree (much like the “Dragon Man” from a study published earlier this year), yet there remains so little evidence of their existence. Most of what we can say as decisive evidence for Denisovans come from DNA evidence, whether from ancient DNA samples or from their DNA traces, which have since interspersed within the DNA of modern humans since the time when the two groups first interbred thousands of years ago.
In an effort to understand this mysterious group of ancient humans, researchers have been hard at work figuring out just how much of this Denisovan DNA does remain in modern human populations. They knew that Denisovan populations persisted within Siberia from around 300,000 to around 50,000 years ago (in fact, that’s where they got their name—a finger bone fossil from a young female individual was found in Denisova Cave, in Siberia); they also knew that these groups eventually made their way to Southeast Asia at some point, as DNA studies have revealed that indigenous groups stemming from human migrations that started in Southeast Asia carry the most Denisovan DNA by comparison. Specifically, DNA from indigenous Australians and highlanders from Papua New Guinea were previously noted as having the most Denisovan DNA among human populations alive today. That result, however, may be lined up for a revision: a recent study, published in the journal Current Biology, may have just located a group of modern humans with even more Denisovan ancestry: the Ayta Magbukon of the Philippines.
Two evolutionary geneticists, Maximilian Larena and Mattias Jakobsson, both from Uppsala University in Sweden, together with their team, revealed their findings in the said journal. The study compared the DNA from this indigenous group with those of about 1,100 individuals from 118 ethnic groups in the Philippines. Then, they compared what they obtained from DNA obtained from these Papua New Guinea and Australian indigenous populations.
There, the two detailed that while the Papua New Guinea highlanders possessed around 3%-4% of Denisovan DNA, the Filipino Ayta Magbukon possessed nearly 30%-40% more, with theirs totaling up to 5% of all their DNA. According to the study, these results reveal that the Ayta Magbukon retained more of these Denisovan traces, as they have resisted interbreeding with the East Asian populations that arrived into their islands for much longer.
Regardless of the results, study co-author Jakobsson maintains that “it’s unclear how the different Denisovan groups on the mainland and on Southeast Asian islands were related and how genetically diverse they were.” Cosimo Posth, a paleogeneticist from the University of Tübingen in Germany who’s unrelated to the study, also mentioned that “still today there are populations that have not been fully genetically described.” They do recognize that the Denisovans were geographically widespread, so more research needs to be done to further illuminate the answers to their questions.
The Ayta Magbukon have been the indigenous occupants of the Bataan peninsula of the Philippines since time immemorial.
Bibliography
- Bower, B. (2021, August 12). An Indigenous people in the Philippines have the most Denisovan DNA. Science News. Retrieved September 10, 2021, from https://www.sciencenews.org/article/indigenous-people-philippines-denisovan-dna-genetics
- National Commission on Indigenous Peoples. (2020, July 31). Ayta Magbukun. National Commission on Indigenous Peoples, Republic of the Philippines. Retrieved September 10, 2021, from https://ncip.gov.ph/?p=573
- Larena, M., McKenna, J., Sanchez-Quinto, F., Bernhardsson, C., Ebeo, C., Reyes, R., Casel, O., Huang, J.-Y., Hagada, K. P., Guilay, D., Reyes, J., Allian, F. P., Mori, V., Azarcon, L. S., Manera, A., Terando, C., Jamero, L., Sireg, G., Manginsay-Tremedal, R., … Jakobsson, M. (2021). Philippine Ayta possess the highest level of Denisovan ancestry in the world. Current Biology, 0(0). https://doi.org/10.1016/j.cub.2021.07.022
