How quickly the cold came is difficult to say today. But she came, and she drove life before her. Glaciers advanced, and soon the ice covered large parts of the European continent. Many plants died, animals died or fled. And the European prehistoric people who lived on the continent several hundred thousand years ago also moved south, where it was warmer. But apparently they didn’t have to travel very long distances: According to calculations by scientists, large parts of Europe remained tolerably habitable even in the coldest phases of the middle Pleistocene. The cold periods of the Ice Age were therefore less hostile to life on the continent than assumed – and Europe was probably inhabited by more archaic people than expected.
The latest evidence comes from a team led by biologist Jesús Rodríguez from the Cenieh Evolutionary Research Center in Burgos, Spain. The researchers examined the climatic conditions in Europe in the period from 560,000 to 360,000 years ago. They identified habitable areas, i.e. not too cold, too dry or too humid, and determined how much plant growth the land there could once support. They compared the results with the needs of today’s hunter-gatherer cultures. As the scientists now in the journal Scientific Reports to report, there were surprisingly stable habitats in Europe, not only in the extreme south of the continent, but also in most of the area of today’s France.
Other scientists have recently come to similar conclusions. They had studied the so-called last glacial period several hundred thousand years later. Finnish researchers around the geoscientist Miikka Tallavaara from the University of Helsinkithat about 23,000 years ago, when the glaciers in Europe reached their last greatest extent, more than a third of the continent remained habitable. At that time, Europe offered 130,000 people a place to live. A researcher duo from Colorado and Montreal found that there were six major habitats for prehistoric humans in Europe during that period, which ranged from southern France to the north-east of the Iberian Peninsula and were connected to one another. A total of perhaps 100,000 people would have lived there.
Even during the coldest phases, prehistoric people lived in what is now Lower Saxony, at least in the summer
At that time, Europe was already populated by anatomically modern humans of the species Homo sapiens. But only recently did scientists, among others from the Max Planck Institute for Evolutionary Anthropology in Leipzig, find evidence that that Neanderthals were obviously also very good at adapting to cold conditions. In Lichtenberg in Lower Saxony, they examined a storage site from 70,000 years ago. And they were able to prove that Neanderthals had also hunted there during the cold phases of the last ice age. According to the scientists, however, these prehistoric people lived this far north mainly during the summer months; they probably spent the Ice Age winters in warmer latitudes.
Rodríguez’s team started several centuries earlier. Neanderthals did not exist 560,000 years ago; Rather, archaeologists assign prehistoric man fossils from that time in Europe to the species Homo heidelbergensis, a predecessor of the Neanderthals. But that one was not long in coming: More recent DNA analyzes found the first traces of Neanderthals in fossils from northern Spain that are around 400,000 years old. In contrast, the first Homo sapiens appeared in Europe only 40,000 years ago.
Scientists are also interested in what happened at the time of Homo heidelbergensis because they hope it will provide information about the evolution of Neanderthals. A common hypothesis is that in the coldest phases of the middle Pleistocene, prehistoric people lived mainly on the Iberian Peninsula, in what is now Italy and the Balkans. There they were isolated from each other for thousands of years. So their gene pool was severely restricted; this is how the Neanderthals eventually evolved. But this idea is hardly compatible with the findings of the researchers around Rodríguez. The only thing that was cut off from the rest of Europe by the ice was Italy, they write in their study. The remaining habitats were interconnected. And also north of the Alps there were possible habitats for archaic humans for a long time.
However, it is unclear whether prehistoric people really did live wherever they could have lived. The researchers around Rodríguez put the number of archaic people in Europe at that time at between 13,000 in colder times and 25,000 in warmer ones. People would have organized themselves into maybe 500 to 1000 small groups, and there would have been more in the West than in the East. The researchers emphasize that their estimate is conservative. But their number is still five to ten times higher than previous estimates. In any case, the ancestors of Neanderthals would have been numerous enough to explain why they did not become extinct during the coldest periods of the Pleistocene.