Cave in Laos reveals secrets of human migration across Southeast Asia | archeology

What links a fossil found in a cave in northern Laos with stone tools made in northern Australia? The answer: humans. when first Homo sapiens They arrived in Southeast Asia from Africa, and left evidence of their existence in the form of human fossils that had accumulated over thousands of years in the depths of the cave.

The latest evidence from the Tham Pa Ling Cave in northern Laos shows that modern humans spread from Africa into Arabia and Asia much earlier than previously thought. The results were drawn up by an international team of researchers and published in the journal Nature CommunicationsOn the last 13th of June.

Paleoanthropologist Fabrice Demeter, assistant professor at the University of Copenhagen, Denmark, and one of the authors of the leading articles says, in the current situation.

In search of answers

Since the first excavation and discovery of the skull and jawbone in 2009, the cave in Laos has been controversial. The evidence for our early voyages from Africa to Southeast Asia is often dominated by island locations such as Sumatra, the Philippines, and Borneo.

The skull and lower jaw have been identified as belonging to Homo sapiens who migrated through the region. but when? The human remains cannot be directly dated because the site is a World Heritage area and the fossils are protected under Laotian law.

There are few animal bones or suitable cave decorations to date, and the material is too old for radiocarbon dating. For this reason, researchers have turned to glossy dating of the sediments.

The technology relies on a photosensitive signal that resets to zero when exposed to light, but increases over time when protected from light. It was originally used to restrict sediment surrounding buried fossils.

“Without fluorescence dating, this vital evidence would still lack a timeline and the site would be overlooked in the accepted path of spread through the region,” says geochronologist Kira Westaway of Macquarie University in Australia. “Fortunately, this technology is very versatile and can be adapted to different challenges.”

These techniques have indicated a minimum age of 46,000 years – a chronology consistent with the expected moment of the arrival of Homo sapiens to Southeast Asia. But the discovery did not end there.

Human existence for more than 56,000 years

From 2010 to 2023, annual excavations have revealed more and more evidence that humans passed through the cave on their way to Australia. Seven pieces of the human skeleton were found in 15-foot breaks of the sediment.

In the new study, the team overcame these problems by creatively applying strategic dating techniques, such as sequential dating of uranium to the tip of stalactites that were buried in sediment and using sequential dating of uranium coupled with electronic rotation.

“Direct dating of the fossil remains confirmed the age sequence obtained by scintillation, allowing us to propose a comprehensive and safe chronology for the existence of Homo sapiens in Tam Pà Ling,” explains chronobiologist Renaud Joannes-Boyau, associate professor at Southern Cross University, also in Australia.

The new chronology revealed that there has been a human presence in this area for more than 56,000 years. Moreover, the age of the seven-meter-deep fossil – part of the shin bone – provides a timeline for the arrival of modern humans in this area between 86,000 and 68,000 years ago.

This delays the time of arrival in mainland Southeast Asia by about 40,000 years. Although, according to genetics, these early migrations did not contribute significantly to our modern population.

“This is really the litmus paper for Tam Pà Ling Guides,” says Westaway. Finally, we have enough dating evidence to say with confidence when a Homo sapiens They arrived in that area, how long they stayed there, and the route they might have taken.”

Tam Pà Ling Cave is located near the recently discovered Cobra Cave, which was frequented by Denisovans some 70,000 years ago. Although there is no previous evidence of early arrival in mainland Southeast Asia, this area may have been a dispersal route used earlier among human ancestors, long before Homo sapiens.