When the Swedish geneticist Svante Pääbo erupted his bomb eight years ago, the big guesswork started. Pääbo and an international team had published their first version of the deciphered Neanderthal genome and it became immediately clear that even modern people have genes from their last extinct family member to three percent. People and Neanderthals had clearly had sex with each other.
The question now was: are the traces of the long-ago affair still noticeable in today's man? Are there any external characteristics that betray the legacy of Neanderthals?
In fact, the genetic remnants of the distant relatives in some people are reflected in the form of the head. This suggests at least a recent study by scientists from Germany and the Netherlands, who appeared in the journal Current Biology.
At the back slightly flattened head
The team of anthropologist Philipp Gunz of the Max Planck Institute for Evolutionary Anthropology in Leipzig and the neurogeneticist Amanda Tilot of the Max Planck Institute for Psycholinguistics in Nijmegen have studied the influence of traditional Neanderthal DNA in modern genomes on the skull of more than Researched 440 human contemporaries. According to this, modern people, who possess these genetic fragments, have a somewhat flattened head, somewhat flattened at the back – and also a differently shaped brain than humans without the genome segments of the family members extinct 40,000 years ago.
Whether the finding also causes differences in the neurological function of the respective brain remains to be investigated in further studies. However, as main author Simon Fisher of the MPI in Nijmegen has pointed to the scientific journal Science, such differences are likely to be marginal, with the development of the brain ultimately being driven by a variety of genes. It is therefore not about differences in intelligence.
Two genes explain why the modern human brain is so conspicuously round
The Neanderthal genome, of course, curbs the conversion of two genes into neuronal development and, conversely, explains why the brains of modern Homo sapiens representatives are fundamentally so remarkably round. The respective genes URB4 and PHLPP1 mediate the production of nerve cells and insulating nerve sheaths in the back of the brain, which increase greatly in people after birth. Newborns are therefore more likely to have elongated, flat skulls, which are very round in the first year of life.
One of the new findings of the study is that researchers can conclude on the basis of modern genomes that parts of the Neanderthal genome function, which also explains the anatomical differences between the two human species. As the paleoanthropologist Katerina Harvati of the University of Tübingen explained the journal Science, this approach is especially interesting for the brain, because the soft nerve tissue in fossil remains of the Neanderthals is not preserved.
In the meantime, the authors of the new study have announced that they plan to use the UK UK biobank for future studies to investigate further possible influences of the Neanderthal genome on the development of the brain – and possibly explain why the very large brains of these extinct relatives were ultimately inferior to the human brain. (Süddeutsche Zeitung)
Created: 01.01.2019, 22:01