"Again, neanderthal DNA is described as halfway between ours and that of a chimpanzee." Why do you keep saying this? It's not just untrue, it's ridiculous.
Chimpanze DNA, including those pesky indels, comes in around 95% identical to humans.
Neanderthal DNA, by contrast is more than 99% identical.
In terms of base pairs, Neanderthals differ from humans by about 3 million.
Chimps differ by 30 million to 50 million.
And the evolutionary explanation is simple:
- The ancestors of Neanderthals and humans split apart several hundred thousand years ago.
- The ancestors of chimps and humans split apart about five million years ago.
So, naturally there must be more genetic difference between humans and chimps than between humans and Neanderthals.
"Again, neanderthal DNA is described as halfway between ours and that of a chimpanzee." Why do you keep saying this? It's not just untrue, it's ridiculous.
At this point I've documented this claim often enough and well enough here that I have no qualms about calling somebody making a statement such as yours a liar.
Again for any honest people reading this, Neanderthal DNA is typically described as about halfway between ours and that of a chimpanzee, and that's a fact. The Smithsonian's article describes it thus:
The Neanderthal sequences were substantially different from modern human mtDNA. Researchers compared the Neanderthal to modern human and chimpanzee sequences. Most human sequences differ from each other by on average 8.0 substitutions, while the human and chimpanzee sequences differ by about 55.0 substitutions. The Neanderthal and modern human sequences differed by approximately 27.2 substitutions.
Half of 55 would be 27.5 of course and any calculator will confirm that for those not able to do that sort of math in their heads.
Not only were Neanderthals' DNA and faces different from ours, their bodies were substantially different and skeletons show the rounded torsos which we observe in apes rather than our own elongated torsos:
The huge genetic gulf explains the lack of any evidence of crossbreeding or of any measurable contribution to our own genome which Neanderthals might have made and honest analyses note this, e.g.
The retrieval of mitochondrial DNA (mtDNA) sequences from four Neandertal fossils from Germany, Russia, and Croatia has demonstrated that these individuals carried closely related mtDNAs that are not found among current humans. However, these results do not definitively resolve the question of a possible Neandertal contribution to the gene pool of modern humans since such a contribution might have been erased by genetic drift or by the continuous influx of modern human DNA into the Neandertal gene pool. A further concern is that if some Neandertals carried mtDNA sequences similar to contemporaneous humans, such sequences may be erroneously regarded as modern contaminations when retrieved from fossils. Here we address these issues by the analysis of 24 Neandertal and 40 early modern human remains. The biomolecular preservation of four Neandertals and of five early modern humans was good enough to suggest the preservation of DNA. All four Neandertals yielded mtDNA sequences similar to those previously determined from Neandertal individuals, whereas none of the five early modern humans contained such mtDNA sequences. In combination with current mtDNA data, this excludes any large genetic contribution by Neandertals to early modern humans, but does not rule out the possibility of a smaller contribution.
Moreover, the idea of us and the Neanderthal having a "Common Ancestor(TM)" is patently idiotic. All other hominids were much further removed from us THAN the neanderthal. "Too far removed to be descended from" is clearly a transitive relationship.
We are not related to the Neanderthal or to any other hominid other than for the remote possibility that we might have somehow been genetically re-engineered from one or more of them. The idea of us having evolved from them is basically disproven.