Less and less more and more similar
Neanderthals lived in Europe more than twice as long as modern humans have managed to date. In the long period of their dominance, a lot must have happened in their populations, the old people researchers guild suspected - and was now able to take a closer look for the first time.
The best-known of all residents of the Düsselklamm between Erkrath and Mettmann is, depending on your perspective, at the same time "Image" and young. When construction workers dug up his ancient mortal remains in the Neandertal in 1856, he had been lying in the place where he had breathed his last for around 40,000 years. However, the most famous specimen of a Homo neandertalensis, because it was the first specimen found, also belonged to a relatively young representative of its species ancestry. After all, when the now prominent prehistoric man in the Neandertal began to rot, his species had inhabited Europe's caves for perhaps 300 millennia - and probably would not have had to share the first nine tenths of these years with any other human species. alt="
The conquest of Europe by superior African Homo sapiens with a migration background changed a lot about thirty millennia ago. The expansive modernity from Africa against the apparently hopelessly outdated Neanderthal Europeans - that almost inevitably led to the first genocide in human history, in the first human-caused extermination of a species, researchers of human history have long interpreted. Whether Neanderthals died fighting or silently, whether Homo sapiens played a more active or passive role, remains uncertain. But one thing is certain: the last of all Neanderthals died a long time ago, without a trace or consequence for the gene pool of the new rulers of Europe. A mixing of Homo sapiens and Homo neandertalensis rule out genetic studies. So far there is agreement among early and prehuman researchers.
Making an exact science out of the vague almost-roughly-about-about-millennia dating continues to give the average anthropologist many opponents in their own profession. Well - sometime around 35,000 years ago the invasion of modern humanity began on the old continent, sometime around 30,000 years ago the last Homo neandertalensis breathed its last. Exactly when is just as controversial as the theories about how quickly, how exactly and why Homo sapiens became widespread.
Catherine Hänni from the French state research organization CNRS and her colleagues are also concerned with a question that can very quickly lead to the heart of this battle zone of prehistoric science: How related were humans and Neanderthals at the beginning and at the end of their European cohabitation? What has changed genetically since the arrival of Africans? Did they really wipe out those, or was the whole of Neandertal already run down and at the end when it fought its rearguard action against Homo sapiens?
Hänni and Co avoided the controversy by providing new answers with much older bones - they examined the fossil molar of a child Neanderthal who once lived around 100,000 years ago in what is now Belgium near the Meuse. For the purposes of the researchers, the "approximately" does not bother us any further - because it is certain that more than fifty millennia would pass before a Neanderthal could see a Homo sapiens here. The DNA of the individual therefore guarantees early Neanderthal genes unspoiled by modernity.
Error-free sequencing of such ancient genomes is still a masterpiece in itself. At least the place where the tooth was found seemed to have a fairly DNA-conserving effect: from rhinoceros bones that were discovered in the find cave, DNA that was at least 60,000 years old could already be sequenced and local cave bear remains still contained verifiably usable genetic material. So, with hope, the Neanderthal tooth was treated in specialized laboratories by technicians whose DNA sequences were precisely known in order to be able to detect any contamination with their Homo sapiens genome. Eventually, it was undoubtedly possible to enrich for four fragments of mitochondrial DNA from the long-dead Belgian Neanderthal and to derive a 123 base pair DNA sequence that must have been typical of ancient Neanderthals.
The sequence reveals major differences to comparable base pair sequences of modern mitochondrial DNA from Homo sapiens - and thus once again confirms what was no longer controversial anyway: A mixing of humans and Neanderthals probably did not take place. But the ancient DNA also differs not a little from that of the younger Neanderthal specimens, which lived more during the fleeting coexistence of Homo sapiens and neandertalensis. Although the young and old classes of Neanderthals are much more similar than their peers with humans, the genetic bandwidth was apparently still quite large in the early days of the Neanderthals, but was noticeably lower at the end of time around the arrival of Homo sapiens.
To put it another way: maybe even before the alleged genocide by the immigrating Africans only a genetically quite uniform ancestry of the native human species had survived. An event that turns a genetically diverse species into a monotonous species is called a bottleneck by evolutionary researchers - and apparently the Neanderthals also had to go through such a bottleneck more than 42,000 years ago, Hänni and Co. surmise.
The hard-fought research result of Hänni and colleagues ultimately raises more questions than it answers - which does not have to be the worst of all results and gives rise to all kinds of speculation. Perhaps, according to an excerpt from the researchers' unsubstantiated potpourri of explanations, sub-populations of the Neanderthals were geographically isolated and then selectively wiped out except for a few branches, perhaps the climate played a role in this. And maybe modern man came along earlier than previously thought and every now and then took a few delicate, starving Neanderthal gene lines off the field forever? In order to be able to say more, a couple of new, as old as possible, genome sequences from Neanderthals that are still young, and therefore really ancient, urgently need to be examined, say the researchers. Which of course they're saying what they've always said.