Philippines' Ayta found to have world's highest percentage of Denisovan ancestry 

MANILA, Philippines — A group of Indigenous Peoples from the Philippines has been found to have the highest level of ancestry of archaic human species, which scientists claimed to be a key finding in the study of human evolution.

The Ayta Magbukon, mostly found in Bataan, is said to possess ∼30% to 40% greater Denisovan ancestry than their Australian and Papuan counterparts.

The study, published last August 12 by Scientific journal Current Biology, is a group of comprehensive analyses of archaic ancestry that featured 118 Philippine ethnic groups based on ∼2.3 million genotypes.

"Together with the recently described Homo luzonensis, we suggest that there were multiple archaic species that inhabited the Philippines prior to the arrival of modern humans and that these archaic groups may have been genetically related. Altogether, our findings unveil a complex intertwined history of modern and archaic humans in the Asia-Pacific region, where distinct Islander Denisovan populations differentially admixed with incoming Australasians across multiple locations and at various points in time," read the study's summary.

Denisovans are extinct species that were first identified in 2010. It was identified through mitochondrial DNA from a juvenile female finger bone from the Denisova cave, from which it was named after, in Siberia, Russia.

Prior to these findings from the Philippines, scientists' only fossil evidence of Denisovans were only five small bones from the cave of Siberia's Altai mountains, and possibly, a jawbone from a Tibetan plateau. 

Researchers write that since modern humans' exit out of Africa, Denisovans have interbred with archaic hominins.

Denisovans, in particular, were initially thought to have a "simple shared demographic history" with modern humans through a single admixture event with the ancestor of Australasians. Australasians is the collective term for the shared genetic ancestry between Philippine Negritos and Australopapuans. Admixture in genetics occurs when previously isolated genetic lineages mix.

"Island Southeast Asia is still relatively underrepresented. However, this may change in the future given the increased interest in the region. Our study, together with the recent discoveries on Homo luzonensis and Homo floresiensis, brings Island Southeast Asia at the forefront of research in human evolutionary history," Maximilian Larena, one of the study's authors and researcher at Uppsala University, was quoted in a CNN report. 

The project is recognized by and implemented in partnership with the National Commission for Culture and the Arts (NCCA) of the Philippines, in accordance with the provisions of Philippine Republic Act 7356 or the Law Creating the NCCA. The Philippines' National Commission for Indigenous Peoples (NCIP), local government units, and regional cultural organizations helped in facilitating its fieldwork.

The project was reviewed and approved by the Regional Ethical Review Board in Uppsala, Sweden.