Reporting on Climate Change and Post-Glacial Human Dispersals in Southeast Asia in the journal Molecular Biology and Evolution, Prof. Richards and his international team have concluded that more complex, and hence older, mitochondrial DNA is found in some South East Asian island populations, consistent with continuity in the population of these islands since modern humans arrived in Australasia some 50,000 years ago; moreover, this lineage can be shown to have actually expanded in the opposite direction – into Taiwan – within the last 10,000 years. Says Prof. Richards: ‘These population expansions had nothing to do with agriculture, but were most likely to have been driven by climate change, in particular, global warming and the resulting sea-level rises at the end of the Ice Age between 15,000 and 7,000 years ago. At this time the ancient continent known as Sundaland – an extension of the Asian landmass as far as Borneo and Java – was flooded to create the present-day archipelago.
‘Although sea-level rise no doubt devastated many communities, it also opened up a huge amount of new coastal territory for those who survived. Our genetic evidence suggests that probably from about 12,000 years ago these people began to recover from the natural catastrophes and expanded greatly in numbers, spreading out in all directions, including north to Taiwan, west to the South East Asian mainland, and east towards New Guinea.’ Quite apart from the implications for the understanding of migration patterns in south east Asia, Prof. Richards and his colleagues argue that findings re-emphasise the critical role of climate change — in particular global warming after the Last Glacial Maximum of c.21,000 years ago — in shaping the evolution of the modern human gene pool, just as, in Europe, the spread of modern humans into western, central, and northern Europe can be traced in genetic haplogroups that derive from small survivor populations moving out from glacial refuges in South West Europe after the retreat of the glaciers from around 15,000 years ago. •
This article is an extract from the full article published in World Archaeology Issue 31. Click here to subscribe