Neanderthal Y chromosomes

26 Sep 2020

At https://phys.org/news/2020-09-neandertals-male-sex-chromosome-modern.html ... the Neanderthal DNA sequence was first done in 1997 - but only on the skeletons of females. It was therefore based on mitochondrial DNA. Later, new molecular techniques were developed which led scientists in Germany to determine better quality sequences of the autosomal genome of several Neanderthals, resulting in the discovery of the Denisovans. However, no male specimens of Neanderthal had at that time been found with preservation allowing the extraction of DNA. A new study claims to rectify that by comparing 3 Neanderthal Y chromosomes with the Denisovan sequence, and also with modern human Y chromosomes. They had a surprise we are told. Neanderthal males possessed modern human Y chromosomes. The assumed Neanderthal Y chromosomes were absent. We are now being told that modern humans mated with Neanderthals between 370,000 and 100,000 years ago and their descendants expunged the Neanderthal Y chromosomes. This is desperate stuff that is intrinsically linked to the politicised science of the Out of Africa meme. It is becoming clear that Neanderthals were not really that much different from modern humans - and now we have a direct genetic connection. Okay, the body shape may have differed but body shape has been evolving as humans have become more and more civilised. In one Sci Fi movie the extraterrestrials had evolved to little more than their heads. Everything else had become surplus to requirement as robots did the lifting and shifting etc.

They compared the Neanderthal Y chromosome with that of Denisovans from a Siberian cave and found the Neanderthals had a closer match to Modern Humans than to Denisovans. That result might be overturned in the future as it is thought the Denisovans branched off from the Neanderthals. On this evidence they did not, which might be a superficial initial finding. Genetics is still in a formative phase and new techniques are being found all the time. We had been told that Neanderthals died out although the MtDNA seemed to show some 4 per cent of Neanderthal DNA in the genome of modern humans. Now we have an entire Y chromosome connection.

Note ... what is meant in this description of modern humans are the discovery of bones and skull fragments that seem to look more like modern humans than other hominims in Ethiopia and Morocco, the oldest of which have been dated around 370,000 years ago. No genetic signature has been attached to these so called early examples of modern humans in which to compare with the Neanderthals. One day that might happen. We also have the Out of Africa theory being pushed back to 100,000 years ago because of apparently similar discoveries of what looks like modern humans in the Levant at that time - and on top of that last week we had footprints of 'modern humans' preserved in northern Arabia from the last interglacial period. The modern humans in the genetic testing however included humans of the recent historical past, and a bit older. No DNA from the so called ancient modern humans. Is the discovery of the Neanderthal Y chromosomes another nail in the coffin of Out of Africa?

See also https://www.sciencemag.org/news/2020/09/how-neanderthals-lost-their-y-ch...