California State University, Northridge anthropologist Hélène Rougier’s efforts to painstakingly reconstruct Neandertal and early modern human remains found in Belgium caves more than 150 years ago are continuing to shed light on what human life was like in Europe thousands of years ago.
The latest findings by Rougier and an international, interdisciplinary team of researchers show that Neandertals and early modern humans (Homo sapiens) had very similar diets, and contradicts a popular hypothesis that Neandertals disappeared because of a limited diet.
By studying the DNA of early modern humans who lived in southwest Europe in the millennia following the last ice age, which lasted from 25,000 to 19,000 years ago, the researchers found a diverse genetic history, indicating those groups of early modern humans connected at an earlier time than scientists originally thought.
“While there are still a lot of questions we want to answer, these latest studies are giving us insights into what human life — for Neandertal and modern humans — was like thousands of years ago,” Rougier said. “This research is giving us a better picture of what society was like in prehistoric times and, as our research continues to move forward, that picture will get clearer.”
The findings on hunter-gatherer ancestry, “Survival of Late Pleistocene Hunter-Gatherer Ancestry in the Iberian Peninsula,” were published last month in the journal Current Biology. The findings on the diets of Neandertals and early modern humans, “Stable isotopes reveal patterns of diet and mobility in the last Neandertals and first early modern humans in Europe,” were published last month in Scientific Reports.
Rougier is one of 31 researchers from around the world working together for more than a decade to explore prehistoric life in Europe, hoping to gain a perspective on what human life was like before recorded history. Their disciplines cross the spectrum, from biological anthropology and archaeology to biochemistry and genetics. Rougier said the interdisciplinary approach provides an opportunity to bring new perspectives and raise questions that individuals in a particular specialty may not consider or be able to resolve.
“This was why we compared them, to see if there were ecological differences or similarities between the two groups which could explain, at least in part, the demise of Neandertals and their replacement by modern humans,” she said.
Using a biochemical analysis to isolate the isotopes — specifically, the chemical elements carbon, nitrogen and sulphur — the researchers found in the remains of Neandertals and early modern humans and faunal remains excavated from the Goyet cave in Belgium more than 150 years ago and then meticulously reassembled by Rougier over the past decade or so.
By studying the isotopes, the researchers were able to learn that the main sources of protein for both species of humans, Neandertals and early modern humans, were land-based plant eaters, mainly mammoths and reindeer. The isotopes also offered insight into the mobility of Neandertals and early modern humans as they looked for food.
“In addition, we note that the individual mobility history of early modern humans may have differed considerably within a group, whereas Neandertal individuals from the same group differed little,” she said. “We hypothesize that more variable, broader and probably strong trans-regional networks existed for modern humans, and the more intensive resource utilization and a more efficient exchange of ideas, and possibly people, were typical for the early modern Europeans at the time of the last Neandertals.
“It is possible that these different concepts of landscape use, in combination with different social and cultural networks, provided modern humans with decisive advantages over Neandertals.”
The Current Biology article examines modern human population movements in Southern Europe during prehistoric times by analyzing the DNA of early modern humans.
The last ice age, Last Glacial Maximum, lasted from about 25,000 to 19,000 years ago. The Late Pleistocene lasted from about 125,000 years ago until about 12,000 years ago.
“We found that the Iberian hunter-gatherers who lived after the Last Glacial Maximum shared some genetic ancestry with earlier hunter-gatherers of the Late Pleistocene, and also with groups that lived miles away during the last ice age,” Rougier said.
The findings confirm the role the Iberian Peninsula in southern Europe played as a refuge during the Last Glacial Maximum for human populations. The new research helps lay the foundation for developing a picture for what human life was like during that time, Rougier said.
She and her colleagues point out in the article that earlier evidence had shown that western and central Europe were dominated by an ancestry associated with an approximately 14,000-year-old individual whose remains were found in Villabruna, Italy. Little was known, until now, about the genetic diversity of early modern humans in southern Europe.
The researchers studied genetic data from the remains of 11 hunter-gatherers and Neolithic individuals from Iberia. The oldest remains were about 13,000 years old. What they found is that individuals from communities scientists thought were isolated interacted with one another.
“This means that early modern humans in the refugia, who we thought had been separated by the climate change of that period — Last Glacial Maximum — found a way to interact,” Rougier said. “We are seeing patterns of human movement we didn’t think existed before.”
Rougier said both studies offer new insights in what prehistoric life was like — insights, she said, that would not have been possible without the interdisciplinary approach she and her colleagues have embraced.
“By sharing our data and working together, we are slowly creating a picture of what prehistoric life was like for Neandertals and early modern humans,” she said. “Each article shares new information we found, but also raises new questions. As we continue to move forward with our research, I am sure we will find new answers and raise even more questions.”