The oldest modern human fossils found in Asia shed light on the migration routes followed by sapiens
In survival, the rule of three prevails, three minutes without air, three hours without shelter, three days without water and three weeks without food can be fatal.. Our ancestors were already well aware of this.. Thanks to this need to have a home, even if it is temporary, we know the customs and even the trips that the first humans made from Africa to Australia.
It turns out that the Tam Pà Ling cave, in northern Laos, hid a secret that has remained within its stone walls for thousands of years.. In this shelter from the elements and almost even from the passage of time, fossil remains that connect Australia with Southeast Asia were preserved.. A finding that shows how modern humans spread across Arabia and Asia earlier than previously thought.
The research, carried out by a team of Laotian, French, American and Australian scientists, has used techniques such as radiometric dating and luminescence to establish a complete and certain chronology for the presence of Homo sapiens (modern humans) in this cave in Laos, according to suggests an article published Tuesday in Nature Communications.
Since the first excavation in this cave in 2009, which found a skull and jawbone, the site has been challenging the belief that humans migrated mainly along the coasts and islands.. Revealing that they also traversed forested areas, possibly following river valleys. Some of these early migrants even settled, becoming the first modern humans to inhabit the region.
The excavations continued from 2010 until this year. Time during which seven pieces of human skeleton were found in different layers of sediments, which accumulated over tens of thousands of years. Remains that have been pushing the time line of migrations even further back in time. As highlighted in the document the main authors of the research, Fabrice Demeter, a paleoanthropologist at the University of Copenhagen, and Kira Westaway, an associate geochronologist at Macquarie University, Australia.
Fossils found in the cave
The new timeline established by the researchers provides valuable information about when the first humans arrived in this area, how long they were there and what route they may have taken.. For example, it shows that humans inhabited the area for more than 56,000 years.
However, the definitive clue, to determine when the first modern humans passed through the region, was hidden seven meters deep.. A leg bone fragment, dating between 86,000 and 68,000 years old, held the key. Thanks to the analysis of this fossil, the arrival of Homo sapiens in mainland Southeast Asia has been delayed by approximately 40,000 years in chronology.
Dating fossils from the Tam Pà Ling cave, located more than 300 kilometers from the sea, has been challenging due to a lack of animal bones or cave decorations suitable for radiocarbon dating.. Since these human fossils are protected by Laotian law they prevent the kind of manipulation necessary for most dating methods.
To overcome this challenge and achieve a more precise chronology, the researchers used luminescence dating techniques, uranium serial dating, and analysis of the sediments under a microscope.. In this way, they analyzed a stalactite tip that had been buried in sediments and two bovine teeth that were 6.5 meters deep.. “Without luminescence dating, this vital evidence would still not have a place on the timeline and the find site would be overlooked in the study of migration through the region,” Westaway said.
Another interesting detail is that this cave is close to the recently discovered Cobra Cave, which was inhabited by Denisovans approximately 70,000 years ago.. This suggests that the region of mainland Southeast Asia may have been used as an early dispersal route by our ancestors, before the arrival of Homo sapiens.