This skull from the Zlatý kůň cave near Prague was one of the earliest known modern humans in Europe. Credit: Marek Jantač
The fossil skull of a woman in the Czech Republic has reconstructed the oldest modern human genome to date, representing a population formed before the ancestors of present-day Europeans and Asians tore apart.
In an article published in Natural ecology and evolution, an international team of researchers analyzes the genome of an almost complete skull that was first discovered in the early fifties in Zlatý Kůň, Czech Republic and is now stored in the National Museum in Prague. The segments of the Neanderthal DNA in its genome was longer than that of the Ust’-Ishim individual from Siberia, the previous oldest modern human sequence, indicating that modern humans lived in the heart of Europe more than 45,000 years ago.
Side view of the mainly complete skull of Zlatý Kůň. Credit: Martin Frouz
Ancient DNA of Neanderthals and early modern humans recently showed that the groups probably entered somewhere in the Near East after modern humans left Africa about 50,000 years ago. As a result, all people outside Africa carry about 2% to 3% Neanderthal DNA. In modern human genomes, the Neanderthal DNA segments have become shorter and shorter over time and can be used to estimate when an individual lived. Archaeological data published last year further indicate that modern humans were already present in south-eastern Europe 47-43 000 years ago, but due to a scarcity of fairly complete human fossils and the lack of genomic DNA, there is little understanding of who these early human colonists were. – or of their relationships with ancient and contemporary human groups.
In a new study published in Natural ecology and evolution, reports an international team of researchers who are probably the oldest reconstructed modern human genome to date. The woman known to researchers as Zlatý kůň (golden horse in Czech), first discovered in the Czech Republic, displays longer pieces of Neanderthal DNA than the 45,000-year-old Ust’-Ishim individual from Siberia, who until so far oldest modern human genome. Analysis suggests that she was part of a population that formed before the populations that gave rise to contemporary Europeans and Asians were torn apart.
A recent anthropological study based on the shape of the skull of Zlatý kůň showed similarities with people who lived in Europe before the last glacier maximum – at least 30,000 years ago – but dating of radiocarbon yielded sporadic results, some so recently than 15,000 years ago. It was only when Jaroslav Brůžek of the Faculty of Science, Prague and Petr Velemínský of the National Museum of Prague collaborated with the genetic laboratories of the Max Planck Institute for the History of Human History, that a clearer picture emerged.
Initial attempts to date Zlatý Kůň, based on the shape of her skull, suggest that she is at least 30,000 years old. Researchers now believe that she lived more than 45,000 years ago. Credit: Martin Frouz
“We found evidence of contamination DNA contamination in the dissected bone, suggesting that a glue-based glue previously used to consolidate the skull returns radiocarbon dates younger than the true age of the fossil,” says Cosimo Posth, co-lead author of the study. Posth was previously a research group leader at the Max Planck Institute for the Science of Human History and is currently Professor of Archeo- and Paleogenetics at the University of Tübingen.
However, it was the Neanderthal DNA that led the team to their greatest conclusions about the age of the fossil. Zlatý kůň had about the same amount of Neanderthal DNA in her genome, as Ust Ishim or other modern humans outside Africa, but the segments with Neanderthal descent were on average much longer.
“The results of our DNA analysis show that Zlatý kůň lived in time closer to the mixed event with Neanderthals,” said Kay Prüfer, co-author of the study.
The scientists could estimate that Zlatý kůň lived about 2000 years after the last mixture. Based on these findings, the team claims that Zlatý kůň represents the oldest human genome to date, about the same age as – if not a few hundred years older than – Ust’-Ishim.
‘It is very interesting that the earliest modern people in Europe have finally failed! As with Ust’-Ishim and the hitherto oldest European skull from Oasis 1, Zlatý kůň shows no genetic continuity with modern humans who lived in Europe after 40,000 years ago, ”says Johannes Krause, senior author of the study and director of the Max Planck Institute for Evolutionary Anthropology.
One possible explanation for the discontinuity is the volcanic eruption of the Campanian Ignimbrite, about 39,000 years ago, which severely affected the climate in the northern hemisphere and possibly reduced the chances of survival of Neanderthals and early modern humans in large parts of Europe during the Ice Age. has.
Micro-sampling of the petrous bone of Zlatý Kůň from the base of the skull in the clean room at the Max Planck Institute for the Science of Human History, Jena. Credit: Cosimo Posth
As advances in ancient DNA reveal more about the history of our species, future genetic studies of other early European individuals will help to reconstruct the history and decline of the first modern humans who migrated from Africa and Eurasia before the formation of the modern time non-African populations.
Reference: “A genome series of a modern human skull over 45,000 years old from Zlatý kůň in the Czech Republic” by Kay Prüfer, Cosimo Posth, He Yu, Alexander Stoessel, Maria A. Spyrou, Thibaut Deviese, Marco Mattonai, Erika Ribechini, Thomas Higham, Petr Velemínský, Jaroslav Brůžek and Johannes Krause, 7 April 2021, Natural ecology and evolution.
DOI: 10.1038 / s41559-021-01443-x