Genetic sequencing of human remains dating back 45,000 years has revealed an unknown migration to Europe and showed that mixing with Neanderthals in this period was more frequent than previously thought.
The research is based on the analysis of several ancient human remains, including a whole tooth and bone fragments, found in a Bulgarian cave last year.
Genetic sequencing found that the remains came from individuals more closely related to current populations in East Asia and the Americas than from populations in Europe.
“This indicates that they belonged to a modern human migration to Europe that was not previously known by the genetic record,” the research published in the journal Wednesday. Nature, dit.
It also “provides evidence that there was at least some continuity between the first modern humans in Europe and the people after Eurasia,” the study added.
Second lower molar of a modern human found in the cave of Bacho Kiro. (MPI-EVA / Rosen Spasov)
The findings “changed our prior understanding of early human migrations to Europe,” said Mateja Hajdinjak, an associate researcher at the Max Planck Institute for Evolutionary Anthropology in Germany, who helped lead the research.
“It showed how even the oldest history of modern Europeans in Europe may have been tumultuous and involved population replacements,” he told AFP.
One possibility raised by the findings is “a dispersal of human groups that will later be replaced (by other groups) later in Western Eurasia, but which continue to live and bring ancestry to the people of Eastern Eurasia,” he added.
The remains were discovered last year in the Bacho Kiro cave in Bulgaria and were hailed at the time as evidence that humans lived alongside Neanderthals in Europe significantly earlier than previously thought.
Genetic analysis of the remains also revealed that modern humans in Europe at that time mixed more with Neanderthals than previously assumed.
All “individuals in Bacho Kiro Cave have Neanderthal ancestors five to seven generations before they lived, suggesting that the mix (blend) between these early humans in Europe and Neanderthals was common,” Hajdinjak said.
Previous evidence of the first mixture of humans and Neanderthals in Europe came from a single individual called Oase 1, which dates back 40,000 years and was found in Romania.
“So far we couldn’t rule out that it was a chance find,” Hajdinjak said.
Human history “lost in time”
The results were accompanied by separate research published Wednesday in the journal Ecology of nature and evolution which includes sequencing the genome of samples from a skull found in the Czech Republic.
The skull was found in the Zlaty kun area in 1950, but its age has been the subject of controversy and contradictory findings in later decades.
Initial analysis suggested it was over 30,000 years old, but radiocarbon dating gave an age closer to 15,000 years.
Genetic analysis now appears to have resolved the issue, suggesting an age of at least 45,000 years, said Kay Prufer, of the Max Planck Institute’s archeogenetics department, who led the research.
“We take advantage of the fact that everyone who traces their ancestry to individuals who left Africa more than 50,000 years ago carries some Neanderthal ancestry in their genome,” he told AFP.
These Neanderthal traces appear in short blocks in modern human genomes, and increasingly longer, further back in human history.
“In large individuals, such as the 45,000-year-old Ust’-Ishim man from Siberia, these blocks are much longer,” Prufer said.
“We find that the genome of the woman Zlaty kun has even longer blocks than those of the man Ust’-Ishim. This makes us trust that he lived at the same time, or even before.”
Despite dating around the same period as the Bacho Kiro, the Zlaty kun skull does not share genetic links with modern Asian or European populations.
Prufer now hopes to study how the populations that produced the two sets of remains were related.
“We don’t know who were the first Europeans to venture into an unknown land,” he said.
“By analyzing their genomes, we are discovering a part of our own history that has been lost in time.”
© France-Presse Agency