The tale of early human migration is being rewritten in light of fossil discoveries in Laos. A fragment of a cranium and a shin bone, two recent findings, indicate that modern humans may have arrived in mainland Southeast Asia far earlier than previously believed.
Early humans are thought to have left Africa between 50,000 and 60,000 years ago and arrived in locations like Southeast Asia shortly after. However, the recently found fossils, which were detailed in the journal Nature Communications on Tuesday, correspond to a time period between 68,000 and 86,000 years ago.
Since 2009, prehistoric human bones have been discovered in the location of these latest discoveries, a cave known as Tam Pà Ling. Jawbones, pieces of the cranium, and a toe bone were among the fossils that, up until this point, had all been dated to a time between 46,000 and 70,000 years ago. The latest findings might move that time frame back by several thousand years.
“At this point we have seven fossils from the site that we’ve identified as definitively human,”Paleoanthropologist Laura Shackelford, who is also a co-author of the study and works at the University of Illinois Urbana-Champaign, explains this to ABC’s Anna Salleh.
The researchers were unable to date the new fossils directly since doing so may harm them because the location is a protected World Heritage site, according to the ABC. Instead, the scientists combined two methods to arrive at their estimate: luminescence dating and dating mammalian teeth discovered in the same stratum of silt. According to Katie Hunt of CNN, luminescence dating establishes how long it has been since sedimentary minerals like quartz or feldspar were heated or exposed to light.
According to Australian geochronologist Andy Herries, who did not participate to the paper, “the dating of the site is excellent and consists of multiple corroborating dating methods.” Although the shin bone could have originated from a different kind of human than Homo sapiens, he tells the magazine that the head bone was “more compelling evidence.”
In other respects as well, the bones are contradicting theories about early human migration. According to the reports of Smithsonian Magazine, the cave is situated in a highly elevated, wooded location far from the beach, contrary to certain study that had suggested that early humans on the move would have stuck to the coasts.
The existence of these oldest known people in Southeast Asia’s ancestors is still up for debate among researchers. According to Kira Westaway, a co-author of the paper and a geochronologist at Macquarie University in Australia, the tribes that undertook these previous migrations may have perished.
The story of a human exodus from Africa approximately 50,000 years ago has been muddied by further fossil discoveries from throughout the globe. In addition, certain early human fossils found in China have been dated to between 70,000 and 127,000 years ago, however these dates are less reliable. Fossils discovered in caves in Greece, Israel, and China have been dated to 210,000 and 180,000 years ago, respectively.