Science. – Negrito ethnic group in the Philippines, Denisovan champion

Madrid, 12 (European Press)

Researchers have known from several lines of evidence that our extinct ancient relatives known as Denisovans interbred with modern humans in the distant past.

Now, a study published in “Current Biology” has found that the Filipino ethnic group Negrito, also known as the Ayta Magbukon, has the highest level of Denisovan ancestry in the world.

In fact, they carry much more Denisovan DNA than the Papuan Highlands, who hitherto been known to the present-day population with the highest level of Denisovan ancestry.

“We made this observation despite the fact that Filipino Negritos have recently mixed with East Asian-associated groups – who carry few Denisovan ancestry – and thus reduced their levels of Denisovan ancestry,” explains Maximilian Larina of Uppsala University, Sweden. And hiding their East Asian ancestry in Filipino negritos, their Denisovans ancestors could be up to 46 percent greater than that of Australians and Papists.”

In the new study, Larina and her colleagues, including Matthias Jacobson, set out to determine the demographic history of the Philippines.

Through a partnership between Uppsala University (Sweden) and the National Commission for Culture and the Arts of the Philippines (NCCA), with the help of indigenous cultural communities, local universities, local government units, NGOs and/or the regional offices of the National Commission for Indigenous Peoples analyzed nearly 2.3 million genotypes from 118 groups. Ethnicities in the Philippines, including various population groups that identified themselves as Negrito. The sample also included genomes with high coverage of the Australian Negro, Papuan, and Eta magbucon.

The study shows that Ayta Magbukon possesses the highest level of Denisovans ancestry in the world, which is consistent with a separate admixture event in Negritos from Denisovans. Together with the recent discovery of a small-bodied hominin, called Homo luzonensis, the data suggest that there were several ancient species that inhabited the Philippines before the arrival of modern humans, and that these ancient groups may have been genetically related.

Taken together, the researchers say, the findings reveal a complex and intertwined history of modern and ancient humans in the Asia-Pacific region, in which distinct groups of Denisovan Islanders mixed differentially with incoming Australians at multiple locations and in different locations.

Jacobson explains: “This admixture resulted in different levels of Denisovan ancestry in the Filipino and Papuan negritos genomes.”

“However, some groups, such as the Ayta Magbukon, mixed sparingly with the new immigrants – he adds -. For this reason, the Ayta Magbukon retained most of their ancient, inherited traits and remained with the highest level of cosmopolitan ancestry.”

He explains that “by sequencing more genomes in the future, we will have a better solution in addressing multiple questions, including how ancient inherited pathways influenced our biology and how they contributed to our adaptation as a species.”