Ancient Homo sapiens bones found in Europe

Ancient homo sapiens
Excavations in the Bacho Kiro Cave in Bulgaria. (Image: Tsenka Tsanova, CC-BY-SA 2.0)

When did the first representatives of Homo sapiens reach Europe? Discoveries from a cave in Bulgaria now provide an answer to this previously contentious question. There, researchers discovered teeth, bones, and numerous stone tools derived from Homo sapiens. According to date, these relics are about 45,000 years old – and thus the oldest clear evidence of the presence of our ancestors in Europe. The old age of these finds also proves that many of the tools originally attributed to the Neanderthal originated from Homo sapiens. The last Neanderthals then looked at these techniques with the newcomers.

For about 250,000 years, the Neanderthal was the dominant human species in Europe. They settled our continent from the Iberian Peninsula to the Urals, leaving behind countless deposits, various tools, and also their dead. But about 45,000 years ago, the era of this early human came to an end: the populations of Homo neanderthalensis shrank, but a new human species spread in Europe – Homo sapiens. But when our ancestors arrived in Europe and when their first populations established themselves is still unclear, because there are few human fossils from that time. The oldest clearly dated relics of our species in Europe were the approximately 41,000-year-old bones of homo sapiens from the Pestera cu oasis, a cave in Romania. This is one of the reasons why it is disputed which type of human being produced the approximately 45,000-year-old stone tools, which were found at some excavation sites in Europe. Some attribute them to Neanderthals due to bone finds in the same place, but in others the originator is less clear.

45,000-year-old Homo sapiens relics

Now discoveries in the Bacho Kiro Cave in Bulgaria provide a new answer to these questions. In the 1970s, numerous stone tools and some human bone fragments were discovered in this site about 70 kilometers south of the Danube. Since 2015, an international team of researchers led by Jean-Jacques Hublin from the Max Planck Institute for Evolutionary Anthropology in Leipzig has been carrying out further excavations there. In one of the layers in the cave bottom, they came across more than 2,000 stone tools, bone beads, pendants, and thousands of animal bones with traces of processing. Some teeth and bone fragments of human origin were also included. “Most of the bones from the Pleistocene are so fragmented that you can’t tell at first glance what they come from,” explains co-author Frido Welker of the University of Copenhagen. “However, because the amino acid sequence of proteins differs from type to type, we can assign these bone finds using protein mass spectrometry.” At the same time, the researchers also isolated genetic material from the teeth and pieces of bone, allowing them to draw conclusions about their species affiliation.

The analyses revealed that the relics clearly come from Homo sapiens and thus from our species. This suggests that the tools found in the cave were also made by these anatomically modern humans. But when was this? To find out, a second-team led by Hublin’s colleague Helen Fewlass subjected much of these finds to extensive radiocarbon dating. “This gives us a very clear picture of when Homo sapiens inhabited this cave,” the researcher said. The radiocarbon date from the Bacho-Kiro cave are the largest data set ever collected from an Ancient Age site and at the same time the most precise. According to this, the finds date from 45,820 to 43,650 years ago, the oldest relics could even be almost 47,000 years old.

Neanderthals looked off Homo sapiens

Thus, the human relics from the Bacho Kiro Cave are the oldest clearly dated finds of Homo sapiens in Europe. “The Bacho Kiro Cave provides us with evidence of the first spread of Homo sapiens in the temperate latitudes of Eurasia,” Hublin says. “These pioneer groups brought new behaviors to Europe and interacted with local Neanderthal groups. This scenario also sheds new light on the stone tools typical of this time around 45,000 years ago. Until now, many of them were assigned to the Neanderthal because they were believed to have originated before the arrival of the first Homo-sapiens representatives. However, the finds in the Bacho Kiro Cave prove that our ancestors were already present at that time and also produced tools of the type of the so-called initial late Palaeolithic. “The initial late Palaeolithic represents a new type of stone tools and new behaviors, including the production of jewelry,” explains Hublin’s colleague Tsenka Tsanova.

The discoveries of the Bacho Kiro Cave now prove that it was not the Neanderthal who developed these techniques, but that they were probably brought along by the then newly immigrated Homo sapiens, Hublin and his colleagues said. But because Neanderthals and Homo sapiens lived side by side and in close contact with each other for several thousand years, the Neanderthals probably adopted some of these techniques. “The age of the material found in the Bacho-Kiro height supports the assumption that the behavioral changes in the dwindling Neanderthal populations stemmed from contact with the immigrant Homo sapiens,” the researchers say. This explains why tools of the initial late Palaeolithic were also discovered at some sites of the last Neanderthals.

Source: Jean-Jacques Hublin (Max Planck Institute for Evolutionary Anthropology, Leipzig) et al., Nature, doi: 10.1038/s41586-020-2259-z; Helen Fewlass Max Planck Institute for Evolutionary Anthropology, Leipzig) et al., Nature Ecology & Evolution, doi: 10.1038/s41559-020-1136-3