Reconstructing the relationship between modern humans and Neanderthals

PART. 2

Neanderthals adopted many innovations

The extensive analyses showed that the samples from the Châtelperronian layers are between 41,000 and 35,500 years old and therefore must indeed be assigned to this culture. In addition, the ages of the Châtelperronian finds overlapped with the finds from other layers—which rules out any mixing of the sediments. With an age of 41,500 years, the Neanderthal skeleton from Saint-Césaire also fits into the picture excellently.

The Neanderthals could thus also have created the CP industries in France. Could have. But there was still a lack of unambiguous evidence that the bones from the CP layer in the Grotte du Renne once belonged to Neanderthals—and not to modern humans.

The team working with Hublin therefore applied completely new methods for the first time in its study: Peptide Mass Fingerprinting and Shotgun Proteomics, two special methods of proteomics. This method can be used to determine whether collagen comes from the bone of a Neanderthal or that of a modern human. Tiny bone samples suffice for the test, and this is the aspect that is crucial and new. And it is also the precise reason why the scientists were able, for the first time, to conduct a molecular analysis of 28 bone fragments from a layer of sediment assigned to the Châtelperronian period.

'They come from Neanderthals,' says Frido Welker. By combining the tests with other proteomic methods—for instance the analysis of the sequence of amino acids of a protein—and paleogenetics, it was ultimately clear that the bone fragments were those of an infant from the Châtelperronian period. 'Our study shows that with paleoproteomics alone, it is possible to differentiate between different Early Stone Age groups within our Homo genus,' according to Welker.

Underestimated artists: for a long time it was thought that Neanderthals could not make jewellery. Max Planck researchers, however, discovered that these ornaments made of antlers, bones, and mussel shells were used by Neanderthals. Credit: MPI for Evolutionary Anthropology/ M. Hardy

The big question overshadowing the studies: How did Homo sapiens get on with Homo neanderthalensis? The new finds can be interpreted in different ways. One could interpret them to mean that the Neanderthals made an unexpected leap forward in their development of their own accord just as Homo sapiens spread across Europe. 'However, that would border on a miracle,' Jean-Jacques Hublin reasons. For him, it is far more likely 'that the two hominids came into contact and the Neanderthals adopted some of the innovations of modern man.'

The Neanderthals could have conceivably found tools and jewellery made by Homo sapiens—and then copied them and introduced them to neighbouring groups when the occasion arose. They were intelligent enough to do so. Perhaps a well-meaning, modern human showed them how to make these wonderful articles. Maybe there were barter transactions between the groups. Who knows? We are back in the realm of ever-popular legends. And Jean-Jacques Hublin again urges caution.

Two percent of our DNA comes from the Neanderthals

There was no need of constant contact for the transfer of cultural innovations and certainly not of any close friendship. Modern humans, too, had to master the harsh life of a hunter and gatherer and was in competition with his contemporaries in the other species for territory and food. Even if there were only dozens or a few hundred groups that seldom encountered each other in the empty world of the Stone Age, most meetings of these contemporaries are more likely to have been unfriendly if not hostile, aggressive and violent.

Admittedly, there is no concrete proof that this was the case. Nevertheless, we know that encounters between competing tribes seldom went smoothly in human history. It is highly likely, therefore, that things would have been no different when Homo sapiens and Neanderthals met.

It is also possible that the women of the competing group were stolen in the process. So it may not have been fiery romances that led to sex between the parties but rather acts of violence. The encounters left demonstrable traces to this day as researchers have known for several years. Around two percent of the DNA in our genome today stems from the Neanderthals—a limited but long-lasting legacy of this long since extinct hominid.

The earth has revealed evidence of the last Neanderthals in layers that are 40,000 or maybe 38,000 years old. At some point during this period, the last of their species disappeared. 'Because of us,' says Jean-Jacques Hublin laconically. From a purely molecular standpoint, the differences between modern humans and Neanderthals are small: a mere 87 proteins separate the two species. Many of them, however, are important for the way the brain works and its development.

Something in modern humans was different. It is possible they took a more aggressive approach than their cousins with whom they were competing; they probably cooperated more effectively in larger teams and in several groups, also showing more empathy and consideration for fellow members.

Experts have found some indications that this was the case. Firstly, modern humans apparently bartered even in the early stages of their time in Europe. For example, mussles from the Mediterranean have been found in Germany. 'That suggests networks operating over larger areas,' Hublin states. 'People knew that fellow humans were living on the other side of the mountains.' And that they wear jewellery and decorate their bodies, as a sign of their allegiance to a larger community consisting of hundreds, perhaps thousands. People who act in solidarity, even if they do not see each other every day. There is nothing like this in the world of the Neanderthals.

Homo sapiens painted pictures from his imagination

Secondly, Homo sapiens painted on cave walls in the early stages of his early European existence, also representing objects that did not exist in reality but only in their imagination. For example, men with lion heads. That means that modern humans recognized stories behind the objects, mythical elements and faith. 'This is a very strong factor which Neanderthals apparently had no feel for', Hublin says.

Things of this nature are 'hard to investigate,' not even with the battery of equipment at the Max Planck Institute in Leipzig. Just how much this frustrates the tech fan is very noticeable. But who knows? Around 40 years ago, when he began his career as a young student, Hublin believed that all the essential elements of human history had already been researched, and that the methodology would not make any more significant progress. 'I could not have been more mistaken.'