Genetic sequencing of human remains dating to 45,000 years ago revealed a previously unknown migration to Europe and during this period, mixing with Neanderthals was more common than previously thought.
The research is based on analysis of several ancient human remains – which contain a whole tooth and bone fragments – that were found in a cave in Bulgaria last year.
According to genetic order, the remains came from individuals who were more closely linked to the current population in East Asia and the Americas than populations in Europe.
“This indicates that they were part of a modern human migration to Europe that was not previously known from the genetic record,” the research, published Wednesday in the journal Nature, said.
It also contains ‘evidence that there was at least continuity between the earliest modern people in Europe and the later people in Eurasia’, the study added.
The findings “shifted our previous understanding of earlier human migrations to Europe,” said Mateja Hajdinjak, a fellow researcher at the Max Planck Institute for Evolutionary Anthropology.
“It showed how even the earliest history of modern Europeans in Europe could have been turbulent and involved population replacements,” she told AFP.
One possibility raised by the findings is a proliferation of human groups which are then replaced [by other groups] later in Western Eurasia, but continues to live and contribute to the descent of the people of Eastern Eurasia, ”she added.
The remains were discovered last year in the Bacho Kiro Cave in Bulgaria and were praised at the time as proof that people lived with Neanderthals in Europe significantly earlier than once thought.
Genetic analysis of the remains also revealed that modern people in Europe at that time mixed more with Neanderthals than was previously assumed.
All the individuals of the “Bacho Kiro Cave” had Neanderthal ancestors five or seven generations before they lived, indicating that the mixture [mixing] between these first people in Europe and Neanderthal people was common, ”said Hajdinjak.
Previous evidence of early human-Neanderthal mixing in Europe comes from a single individual named Oasis 1, which is 40,000 years old and was found in Romania.
“Until now, we could not rule out that it was a coincidental find,” Hajdinjak said.
The findings were accompanied by separate research published Wednesday in the journal Nature Ecology and Evolution, regarding genome sequences of samples of 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 debate and conflicting findings in recent decades.
Initial analysis suggested that it was older than 30,000 years, but dating of radiocarbon gave an age closer to 15,000 years.
Genetic analysis now seems to have solved the issue, suggesting an age of at least 45,000 years, said Kay Prufer of the Max Planck Institute’s Department of Archeogenetics, who led the research.
“We take advantage of the fact that everyone who traces their ancestry back to the individuals who left Africa more than 50,000 years ago has a bit of Neanderthal ancestry in their genomes,” he told AFP.
These traces of Neanderthal appear in short blocks in modern human genomes, and increasingly longer in human history.
“In older 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 Zlaty kun woman has even longer blocks than that of the Ust’-Ishim man. It makes us confident that she lived at the same time, or even earlier. ”
Despite dating to about the same period as the Bacho Kiro remains, the Zlaty kun skull does not share genetic ties with modern Asian or European populations.
Prufer now hopes to investigate how the populations that produced the two sets of surplus are related.
“We do not know who were the first Europeans to venture into an unknown country,” he said.
“By analyzing their genomes, we determine a part of our own history that has been lost over time.”