Skeletal remains unearthed in Laos by a team of international researchers show that anatomically modern humans existed in the region at least 46,000 years ago.The findings, which provide the earliest skeletal evidence for fully modern humans in South East Asia, were published online this week in the prestigious international journal the Proceedings of the National Academy of Sciences.
The international team of researchers included Dr Kira Westaway from Macquarie University’s Department of Environment and Geography. Westaway led the dating component of the project. She was also part of the research team that discovered the skeleton of Homo Floresiensis, dubbed ‘the hobbit’ in Indonesia.
There had been uncertainty surrounding the timing of modern human emergence and occupation in East and South East Asia because of little available fossil evidence, Westaway said. Parts of a skull, including facial bones and teeth, were found in a cave called Tam Pa Ling in northern Laos (Hua Pan Province), about 260 km north east of the capital, Vientiane. The skull features differ from those found in western Eurasian archaic human skeletal remains, she said.
“These skeletal remains provide the earliest evidence for fully modern humans in mainland Southeast Asia and the earliest human fossil in eastern Eurasia, and east of the Jordan Valley that exhibits a suite of modern human morphological features,” Westaway said.
“There are a number of sites in the region containing stone tool evidence that are considerably older but they lack the skeletal evidence”.
The evidence also indicates that contrary to modern human migration patterns concentrated on island and coastal regions, Pleistocene modern humans may have followed inland migration routes to East Asia and Australasia or used multiple migratory paths, Westaway added.
Dating of the remains was established at Macquarie University’s Environmental Science-Luminescence (OSL/TL) laboratory – one of only five such facilities in Australia. Highly-specialised red TL dating equipment was used combined with single-grain dating of individual quartz grains using a focused solid-state diode-pumped laser.
Radiocarbon dating of charcoal was also conducted, but was found to exceed the limits of the technique and therefore only provided a minimum age. However, the combined techniques provided a chronology that suggests the sediment and associated fossils were buried around 46,000 years ago. However, the fossils themselves are likely to be older, Westaway said, as they were probably lying close to the entrance prior to being washed into the cave where the remains were found.