A previously unknown lineage of Europeans survived the coldest parts of the last ice age, only to vanish when Europe went through a warm spell starting about 15,000 years ago.
The discovery comes from the largest study yet to look at the genetic makeup of ice age European hunter-gatherers.
For most of the past 100,000 years, glaciers covered much of Europe. Starting about 45,000 years ago, hunter gatherers began arriving in Europe from Africa through the near East, toughing it out during the Last Glacial Maximum (roughly 25,000 to 19,000 years ago), the coldest part of the last ice age.
Archaeologists know about the first modern humans in Europe from the artifacts they left behind. However, few human fossils remain from those early cultures, so little is known about how these ancient people migrated and were related to one another.
To shed light on this ancient time, scientists have now collected the largest known database of prehistoric European hunter-gatherer genomes. They analyzed the genomes of 356 ancient hunter-gatherers who lived between 35,000 and 5,000 years ago in what are now 34 countries across Eurasia. This included new data from 116 individuals.
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The researchers unexpectedly discovered that the Gravettian culture that was widespread across Europe between about 33,000 and 26,000 years ago was made up of two genetically distinct groups, despite using similar weapons and producing similar art. That was a surprise, study lead author Cosimo Posth, a paleogeneticist at the University of Tübingen in Germany, told Live Science.
One previously unknown Gravettian lineage — dubbed Fournol, after a French site that is the earliest known location associated with this genetic cluster — inhabited what is now France and Spain. Another — named Věstonice after a Czech site — stretched across today's Czech Republic and Italy.
The Fournol descended from the Aurignacians, the earliest known hunter-gatherer culture in Europe, which lasted from about 43,000 to 33,000 years ago. In contrast, the Věstonice descended from the Kostenki and Sunghir groups farther east from what is now western Russia, who were contemporaries of the Aurignacians.
There are some cultural differences between these two lineages. For instance, Fournol people buried their dead in caves, and sometimes may have ritually cut the bones after death, Posth said. In contrast, the Věstonice buried their dead with funeral goods, personal ornaments and the red mineral ochre in open air or cave sites.
People of the Fournol and Věstonice lineages may have possessed darker skin and eye color than some of the lineages that came after them, the new genome study suggests. However, Posth warned that "it is not possible to know their exact skin and eye colors, because those traits might be influenced by multiple other genes."
The Fournol genetic signature survived the Last Glacial Maximum, lasting for at least 20,000 years. Their descendants sought refuge in what is now Spain and southern France during the Last Glacial Maximum and later spread northeast to the rest of Europe.
In contrast, the Věstonice died out. Previously, scientists thought the Italian peninsula was a refuge for Gravettians during the Last Glacial Maximum, with the people there eventually forming the so-called Epigravettian culture after the glaciers retreated. However, the new findings show the Věstonice were not genetically detectable after the Last Glacial Maximum.
Instead, the new study finds the Epigravettians actually descended from Balkan groups that entered Italy as early as 17,000 years ago.
"Right after the Last Glacial Maximum, the genetic makeup of the human groups living in the Italian peninsula changed dramatically," Ludovic Orlando, a molecular archaeologist at Paul Sabatier University in Toulouse, France, who was not involved in the study, told Live Science.
Starting about 14,000 years ago, the Epigravettians spread from the south across the rest of Europe, supplanting the Magdalenians, who were descended in part from the Fournol. The Magdalenians hunted reindeer that lived on the steppe, while the Epigravettians specialized in hunting forest prey. An abrupt warming event helped forests spread across Europe into what once was steppe, and the Epigravettians moved northward as well, Posth said.
All in all, this new research "considerably extends our knowledge of ancient genome human variation in the deep past of Europe," said Orlando, who wrote a perspective on the new study. "It unveils important changes in the genetic makeup of some regions following major climate changes."
The scientists detailed their findings on Wednesday (March 1) in the journal Nature.
