New data on migrations of primitive people confused archaeologists
The discovery of prehistoric fossils shows that primitive people left Africa and reached Asia earlier than previously thought. Humans originated in Africa, but when exactly our earliest ancestors left the continent and how they spread around the world is a subject that archaeologists are actively discussing.
Two fossils found in a cave in northern Laos suggest that our species Homo sapiens lived in the region about 86,000 years ago, according to a new study. The discovery challenges the prevailing idea that people's path around the globe was linear and flowed in a single wave about 50,000 to 60,000 years ago, according to CNN.
“Most likely, this early migration was unsuccessful, but this does not detract from the fact that Homo sapiens arrived in this region by this time, which is a remarkable achievement,” – notes study author Kira Westaway, an assistant professor at Macquarie University in Australia.
DNA analysis of modern human populations has confirmed the hypothesis that early modern humans left Africa around 50,000-60,000 years ago, and archaeologists believe that our early ancestors probably followed coastlines and islands across Southeast Asia to Australia.
However, the growing number of older human remains found in China and the Levant show that this chapter in human history is more complex than it first seemed.
The migration of 50,000-60,000 years ago, “ contribution to our current gene pool may not have been the first, emphasizes Keira Westway. — It is possible that there were earlier migrations that were not successful and therefore did not bring their genetics into our modern populations.
Two Laotian fossils — a fragment of a leg bone and part of the anterior part of the skull — were found in Tam Pa Ling cave. The archaeological site was discovered in 2009 when another partial skull was excavated.
In addition to the latest finds, two jawbones, a rib and a phalanx were also found at the site, and all physical features of the remains suggest that they belonged to early modern humans.
Dating fossils from this site has proven difficult. They were found to be too old for radiocarbon dating, which only dates the remains up to 46,000 years ago. In addition, human fossils found at the site are protected by Laos heritage laws that prevent any kind of destructive analysis.
Instead, the team involved in the study, which was published Tuesday in the journal Nature Communications, used two different methods for estimating the age of fossils.
According to CNN, the researchers measured the glow of quartz and feldspar minerals in a layer of sediment — a method that shows how much time has passed since the material with crystalline minerals was heated or exposed to sunlight.
As the excavations deepened, scientists also discovered two animal teeth in the same layer as the human remains, and dated them by measuring the radioactive decay of uranium isotopes — chemical elements found in tooth enamel, — using a technique called electron spin resonance dating.
The two fossils are estimated to be 68,000-86,000 years old, with a leg bone fragment being the oldest find.
In addition to casting doubt on the chronology of early human migration, this site also challenges conventional wisdom that that the earliest human travel in the region involved circumnavigating coastlines and islands such as Sumatra, the Philippines, and Borneo.
The highland region in the heart of mainland Southeast Asia was and still is densely forested, at an altitude of about 1100 meters and at least 300 kilometers from the sea.
“The most fascinating part of this exploration is the location of the cave . We know that hominins tended to move inland along river valleys, but this location confirms our suspicions that early Homo sapiens had the ability to adapt and disperse through mountain woodlands much sooner than expected,” explains Keira Westway.
Archaeologists believe the cave has been inhabited for nearly 50,000 years, and recent discoveries highlight the region's exciting potential for paleoanthropology.
In a nearby site known as Cobra Cave, a tooth believed to have belonged to a Denisovan was found, « elusive ancient man,” notes CNN. However, this tooth is 70,000 years older than Tam Pa Ling's earliest remains, so there is no evidence that the two species mixed or coexisted at the site, says Westway.
The world's oldest piece of figurative rock art has been found in caves in Indonesia, while extinct human species, including small Homo floresiensis and Homo luzonensis, have been found on the islands of Indonesia and the Philippines.
The team expects to unearth more human fossils in the region .
“This region is the perfect place to ask some of these questions about migration, as mainland Southeast Asia is indeed at the crossroads of East Asia and insular Southeast Asia/Australia, — says senior study author Fabrice Demeter, associate professor at the Lundbeck Foundation's Center for Geogenetics in Copenhagen. – Places like Tam Pa Ling, where there is continuous, undisturbed stratigraphy (layers of sediment) that contains many fossils over a long period of time, will teach us a lot about past migrations and how early modern humans and other hominins changed over time. ;.