It has long been recognized that the Austronesians, an ancient ethnolinguistic lineage of humans, were at least one of the ancestors of the native residents of the islands of Southeast Asia and nearby regions. Their area of influence stretches as far west as Madagascar and as far east as Rapa Nui, an island around 3,500 kilometers (2,200 miles) west of Chile that’s also known as “Easter Island.” Populations within this vast area, stretching the Indian Ocean and close to the entire breadth of the Pacific, share cultural and language roots, and are identifiable in ways such as how they count numbers in their native languages. The sheer vastness of their influence comes as no surprise, as these groups of humans were among the first to develop maritime technologies like outrigger boats and catamarans, allowing them to traverse vast oceans to populate new islands as far back as 3,500 BCE, in an event known as the Austronesian expansion.
These Austronesians, given the age of the ethnolinguistic group, were thought to have brought the first traces of East Asian heritage to the Southeast Asian islands, intermingling with the native peoples who already lived there beforehand. It turns out, however, that these native peoples might have already had East Asian heritage in them before the Austronesians even got there—at least, according to findings from a new study published in the journal Nature.
This new study details an analysis of the remains of what was an 18-year-old woman found in Leang Panninge, a cave located in south Sulawesi, in Indonesia. The woman, nicknamed “Besse” (Bess-ehh) from an affectionate term used by the native residents of south Sulawesi to refer to girls and women, was dated to around 7,300 years old, based on the age of a seed found near the body. Besse was excavated between 2015 and 2019; beside her were various stone points; this, the researchers say, identify her as one of the Tolean people, a hunter-gatherer culture in south Sulawesi with evidence dated from 8,000 to 1,500 years ago who seemingly disappeared afterwards.
DNA analysis of her remains, obtained from dense bone found in the base of her skull, showed that genetically speaking, she is more closely related to the natives of what is now Papua New Guinea and Australia than she is to present-day mainland East Asians. According to the research team, she then belongs to a previously-unknown lineage of East Asians that emerged around 37,000 years ago, right at the time when the evolutionary split between Papuans and Aboriginal Australians occurred. The fact that they even found DNA material on Besse was also striking, as the tropical climate surrounding locales such as Sulawesi are detrimental to the preservation of DNA material in fossils, making their isolation quite rare
Further analysis of Besse’s DNA also showed East Asian heritage, making her finding the “first indication that an Asian ancestry was present in Wallacea long before the Austronesian expansion,” according to author Adam Brumm, an archaeologist from Griffith University in Australia. (Wallacea is a collective term for the group of islands located between mainland Asia and Australia, including the islands of Sulawesi, Flores, and Lombok. It is here where Austronesians spread across East Asia from the Philippines, and where East Asian heritage was previously thought to have been first introduced to the area.) Grumm is joined by Selina Carlhoff, a population geneticist from the Max Planck Institute for the Science of Human History in Jena, Germany, and other colleagues.
Besse also carried with her Denisovan DNA, providing evidence to the theory that Besse’s ancestors arrived on the island long before the Austronesians got there, and intermingled with the already-present Denisovan population. According to Collége de France and Pasteur Institute population geneticist Lluis Quintana-Murci, who’s unrelated to the study, Besse’s discovery shows the typically-unappreciated complexity of the Southeast Asian people, adding that “Wallacea was probably a key habitat region for Denisovan-related groups.” According to DNA analysis, 2.2% of Besse’s DNA came from Denisovan ancestors. (It should be noted, however, that nearby present-day populations also carry high amounts of Denisovan ancestry; in fact, the highest ever recorded was at 5%, from the Ayta Magbukon of the Bataan peninsula in the Philippines.)
The recent study showcased the complexity and variation within the heritage of current Southeast Asian peoples, while also opening a glimpse into the colorful history of humans in the area. (Sulawesi is also known for housing vibrant cave wall paintings made by the ancient peoples that lived there in the past; these paintings, however, are in danger of vanishing due to human-induced climate change.)
Bibliography
- Blust, R. A. (1998, October 19). Austronesian languages. Encyclopedia Brittanica. Retrieved September 17, 2021, from https://www.britannica.com/topic/Austronesian-languages
- Bower, B. (2021, August 25). Ancient DNA shows the peopling of Southeast Asian islands was surprisingly complex. Science News. Retrieved September 17, 2021, from https://www.sciencenews.org/article/ancient-dna-skeleton-woman-indonesia-peopling-southeast-asian-islands
- Carlhoff, S., Duli, A., Nägele, K., Nur, M., Skov, L., Sumantri, I., Oktaviana, A. A., Hakim, B., Burhan, B., Syahdar, F. A., McGahan, D. P., Bulbeck, D., Perston, Y. L., Newman, K., Saiful, A. M., Ririmasse, M., Chia, S., Hasanuddin, Pulubuhu, D. A. T., … Brumm, A. (2021). Genome of a middle Holocene hunter-gatherer from Wallacea. Nature, 596(7873), 543–547. https://doi.org/10.1038/s41586-021-03823-6
- Matisoo-Smith, E. (2015). Ancient DNA and the human settlement of the Pacific: A review. Journal of Human Evolution, 79, 93–104. https://doi.org/10.1016/j.jhevol.2014.10.017
