The oldest genomes of anatomically modern humans in Europe have been sequenced

Few genomes have been sequenced from the first anatomically modern humans who arrived in Europe when the continent already had Neanderthal populations. Scientists have now sequenced the oldest known genomes of anatomically modern humans in Europe and carried out a detailed analysis of them.

The work was carried out by an international team led by Arev P. Sümer, from the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

After anatomically modern humans left Africa, they encountered Neanderthals and there were cases of mixed couples having joint offspring, resulting in the two to three percent of Neanderthal DNA that can be found today in humans. genomes of people from outside Africa. However, little is known about the genetics of these pioneers in Europe and the time when the mixture occurred.

A key paleontological site in Europe is Zlatý kůň, in the Czech Republic, where a complete skull of a single individual who lived around 45,000 years ago and was previously genetically analyzed was discovered. However, due to a lack of archaeological context, it was not possible to link this individual to any archaeologically defined group.

A nearby site, Ilsenhöhle in Ranis (Germany), about 230 kilometers from Zlatý kůň, is known for a specific type of archaeological remains, from a culture called Lincombiana-Ranisiana-Jerzmanowician (LRJ), dating back to about 45,000 years ago. years. It has long been debated whether the LRJ culture was the work of Neanderthals or, conversely, the first anatomically modern humans.

Although mostly small bone fragments are preserved in Ranis, a previous study was able to analyze the mitochondrial DNA of thirteen of these pieces and this revealed that they belonged to anatomically modern humans and not Neanderthals. However, since the mitochondrial sequence only constitutes a tiny part of the genetic information, relationships with other anatomically modern humans remained a mystery.

Now, analysis of the nuclear genomes of 13 Ranis specimens reveals that they represented at least six individuals. The size of the bones indicates that two of these individuals were in their infancy when they died. Another piece of information obtained is that, genetically, three were men and three were women. Additionally, among these individuals, there were a mother and her daughter, as well as other more distant biological relatives.

The team also sequenced more DNA from the female skull found at Zlatý kůň, producing a high-quality genome for this woman. “To our surprise, we discovered a fifth or sixth degree genetic relationship between Zlatý kůň’s wife and two individuals from Ranis,” explains Arev Sümer, lead author of the study. “This means that Zlatý kůň’s wife was genetically part of the extended family of Ranis and probably also made tools typical of the LRJ culture.”

Illustration of what Zlatý kůň’s wife may have looked like in life. She belonged to the same population as the Ranis individuals and was closely related to two of them. (Image: © Tom Björklund for the Max-Planck-Institut für evolutionäre Anthropologie)

Among the remains of the six Ranis individuals, one of the bones is particularly well preserved; in fact, it is the best preserved anatomically modern human bone from the Pleistocene for DNA extraction. This allowed the team to obtain a high-quality genome from this male individual, known as Ranis13. Together, the genomes of Ranis13 and that of the Zlatý kůň woman represent the oldest, high-quality anatomically modern human genomes sequenced to date.

By analyzing the genetic variants related to phenotypic traits, they discovered that the Ranis and Zlatý kůň individuals were carriers of variants associated with dark skin and hair, as well as brown eyes, still reflecting the African origin of that nascent European population.

By analyzing the segments inherited from the same common ancestor in the genomes of Ranis and Zlatý kůň, the researchers estimate that their population was composed of, at most, a few hundred individuals that were possibly distributed over a broader territory. The study authors found no evidence that this small early population of anatomically modern humans left genetic inheritance in later Europeans or any other global population.

Members of the Zlatý kůň/Ranis population coexisted with Neanderthals in Europe, raising the possibility that they may have had Neanderthals among their recent ancestors following their migration to Europe. Previous studies on anatomically modern humans from more than 40,000 years ago found evidence of events that occurred shortly before joint descent between anatomically modern humans and Neanderthals. However, no evidence of joint and close descent in time with Neanderthals was detected in the genomes of the Zlatý kůň/Ranis individuals.

“The fact that groups of anatomically modern humans, who apparently arrived in Europe later, show this Neanderthal ancestry, while those of Ranis and Zlatý kůň do not, could mean that the oldest lineage of Zlatý kůň/Ranis penetrated Europe by a different route or this one did not coincide much with points populated by Neanderthals,” speculates Kay Prüfer, who co-supervised the study.

The Zlatý kůň/Ranis population represents the earliest known divergence of the group of anatomically modern humans that migrated from Africa and subsequently dispersed across Eurasia. Despite this early separation, the Neanderthal ancestry in Zlatý kůň and Ranis comes from the same ancient admixture event that can be detected in all people originating outside of Africa today. By analyzing the length of segments inherited from Neanderthals in the high-coverage genome of Ranis13 and using direct radiocarbon dating of this individual, the researchers placed this shared admixture event with Neanderthals between 45,000 and 49,000 years ago.

Since all current non-African populations share this Neanderthal ancestry with those ancient Zlatý kůň and Ranis settlers, this implies that between 45,000 and 49,000 years ago a unified ancestral non-African population still existed. These results indicate that any anatomically modern human remains found outside Africa older than 50,000 years could not have been part of the common non-African population that had joint descent with Neanderthals and from which the inhabitants of much of the world descend. , as Johannes Krause, co-author of the study, reasons.

The study is titled “Earliest modern human genomes constrain timing of Neanderthal admixture.” And it has been published in the academic journal Nature. (Source: Max-Planck-Institut für evolutionäre Anthropologie / NCYT by Amazings)