Genetic sequencing of human remains that are 45,000 years old has revealed a previously unknown migration to Europe and showed that mixing with Neanderthals was more common during that period than previously thought.
The research is based on analysis of several ancient human remains – including a whole tooth and bone fragments – found in a cave in Bulgaria last year.
Genetic sequencing indicated that the remains came from individuals more closely associated with current populations in East Asia and America than populations in Europe.
“This indicates that they belonged to a modern human migration to Europe that was previously unknown from the genetic data,” the study published in the journal Wednesday. Nature, said.
It also provides “evidence that there was at least some continuity between the earliest modern humans in Europe and later humans in Eurasia,” the study added.
Second lower molar of a modern human found in the Bacho Kiro Cave. (MPI-EVA / Rosen Spasov)
The findings “changed our previous understanding of early human migrations to Europe,” said Mateja Hajdinjak, an associate researcher at Germany’s Max Planck Institute for Evolutionary Anthropology, who helped lead the study.
“It showed how even the earliest history of modern Europeans in Europe was tumultuous and that population replacements were needed,” she told AFP.
One possibility raised by the findings is “a spread of human groups that are later replaced (by other groups) in Western Eurasia, but continue to live and contribute to the ancestors of the people of Eastern Eurasia,” added them to it.
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 ever thought.
Genetic analysis of the remains also revealed that modern humans in Europe mingled more with Neanderthals at the time than previously thought.
All “Bacho Kiro caves have Neanderthal ancestors five to seven generations before they lived, suggesting that the mixing (mixing) between these early humans in Europe and Neanderthals was common,” said Hajdinjak.
Earlier evidence for early human-Neanderthal mixing in Europe came from a single person named Oase 1, who is 40,000 years old and found in Romania.
“Until now, we couldn’t rule out the possibility that it was an accidental find,” said Hajdinjak.
Human History ‘Lost in Time’
The findings were accompanied by separate research published Wednesday in the journal Natural Ecology and Evolution with genome sequencing of skull samples found in the Czech Republic.
The skull was found in the Zlaty kun area in 1950, but its age has been the subject of debate and conflicting findings over the decades.
Initial analysis suggested it was older than 30,000 years, but radiocarbon dating gave an age closer to 15,000 years.
Genetic analysis now appears to have settled the matter, suggesting an age of at least 45,000 years, said Kay Prufer of the Max Planck Institute’s department of archeogenetics, who led the study.
“We’re taking advantage of the fact that anyone who traces their lineage back to the individuals who left Africa more than 50,000 years ago has a little bit of Neanderthal lineage in them,” he told AFP.
These Neanderthal traces appear in short blocks in modern human genomes, and in longer and longer blocks further back in human history.
“In older individuals, such as the 45,000-year-old Ust’-Ishim man from Siberia, these blocks are much longer,” said Prufer.
“We find that the genome of the Zlaty kun female has even longer blocks than that of the Ust’-Ishim male. This gives us confidence that she was alive at the same time or even earlier.”
Despite dating from roughly the same period as the remains of 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 unfamiliar country,” he said.
“By analyzing their genomes, we discover a part of our own history that has been lost over time.”
© Agence France-Presse