In an article published in Nature Ecology & Evolution, an international team of researchers analyses the genome of an almost complete skull first discovered in Zlatý Kůň, Czechia in the early 1950s and now stored in the National Museum in Prague. The segments of Neanderthal DNA in its genome were longer than those of the Ust’-Ishim individual from Siberia, the previous oldest modern human sequenced, suggesting modern humans lived in the heart of Europe more than 45,000 years ago.
“We found evidence of cow DNA contamination in the analyzed bone, which suggests that a bovine-based glue used in the past to consolidate the skull was returning radiocarbon dates younger than the fossil’s true age,” says Cosimo Posth, co-lead author of the study. Posth was formerly a research group leader at the Max Planck Institute for the Science of Human History and is currently Professor of Archaeo- and Palaeogenetics at the University of Tübingen.
However, it was the Neandertal DNA that led the team to their major conclusions about the age of the fossil. Zlatý kůň carried about the same amount Neanderthal DNA in her genome, as Ust Ishim or other modern humans outside Africa, but the segments with Neanderthal ancestry were on average much longer.
“”The results of our DNA analysis show that Zlatý kůň lived closer in time to the admixture event with Neanderthals,” says Kay Prüfer, co-lead author of the study.
The scientists were able to estimate that Zlatý kůň lived approximately 2,000 years after the last admixture. Based on these findings, the team argues that Zlatý kůň represents the oldest human genome to date, roughly the same age as — if not a few hundred years older than — Ust’-Ishim.
“It is quite intriguing that the earliest modern humans in Europe ultimately didn’t succeed! Just as with Ust’-Ishim and the so far oldest European skull from Oase 1, Zlatý kůň shows no genetic continuity with modern humans that lived in Europe after 40,000 years ago,” says Johannes Krause, senior author of the study and director at the Max Planck Institute for Evolutionary Anthropology.
One possible explanation for the discontinuity is the Campanian Ignimbrite volcanic eruption roughly 39,000 years ago, which severely affected climate in the northern hemisphere and may have reduced the survival chances of Neanderthals and early modern humans in large parts of Ice Age Europe.
As advances in ancient DNA reveal more about the story of our species, future genetic studies of other early European individuals will help to reconstruct the history and decline of the first modern humans to expand out of Africa and into Eurasia before the formation of modern-day non-African populations.