Abstract
Expansion of anatomically modern humans (AMHs) into Southeast Asia is best understood in the context of environmental changes that occurred over the past 120,000 years. These saw marked fluctuations in temperature that affected both vegetation and sea levels. Current evidence suggests that AMHs reached Southeast Asia by 60,000-50,000 years ago. En route, they interbred with indigenous Denisovans, and may well have encountered other hominin species named after the islands of Flores and Luzon. Southeast Asia has a warm and inviting climate, that would have supported an abundance of fish, mammals, and plant foods. Hunter gatherers flourished there for tens of millennia, seen in open sites and rock shelters. What we miss, is the marine adaptation due to the drowning of sites with the rising sea level from about 12,000 years ago. However, on raised beaches formed when the sea level rose higher than at present, complex sedentary hunter gatherer communities have been identified. From about 4,800 years ago, the first rice and millet farmers expanded into Southeast Asia from the north and mixed with indigenous hunter gatherers whose genetic signature is still to be found in modern populations. Only in remote habitats, such as deep rainforests, do the descendants of the hunter gatherers survive.