Southeast Asia was crowded with archaic human groups long before we turned up
Around 55,000-50,000 years ago, a population of modern humans left Africa and started on the long trek that would lead them around the world. After rapidly crossing Eurasia and Southeast Asia, they traveled through the islands of Indonesia, and eventually as far as the continent of Sahulmodern-day Australia and New Guinea. Their descendants are the modern human populations found right across this enormous region today.
In new research published in Proceedings of the National Academy of Sciences, we detail how during this remarkable journey the ancestors of modern humans met and genetically mixed with a number of archaic human groups, including Neandertals and Denisovans, and several others for which we currently have no name. The traces of these interactions are still preserved in our genomes. All modern non-African populations contain about 2 percent Neandertal ancestry.
When modern humans headed south down the Malaysian Peninsula and into Island Southeast Asia (ISEA) a big surprise awaited. They found the area was already crowded with different archaic human groups, including completely different species of humans. The incoming modern human population apparently first met and mixed with a distant relative of the Denisovan humanoids in the area, leaving a signal in the genomes of Australo-Papuans and several ISEA populations.
The wave of modern humans did not wait long to cross into Australia around 50,000 years ago when sea levels were up to 120 metres lower than today. While there is one much earlier Australian site, the 65-80,000 year old Madjedbebe rock shelter in Arnhem Land, it is a complete outlier to the rest of the Australian record and the age of the site has been queried.
Island Southeast Asia (ISEA) was clearly a very crowded place around 50,000 years ago, occupied by many different archaic human groups on many different islands. But shortly thereafter there was only one survivor: us.
Full article:
https://phys.org/news/2019-07-southeast-asia-crowded-archaic-human.html