"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.
wendy1946:
"I have no qualms about calling somebody making a statement such as yours a liar." So you add to your ridiculous claims the charge that I am "a liar"?
Even when I provided easily understood references, you cannot be bothered to take time to explain how my references differ from yours, but immediately claim that I, not they are lying?
I'd say you've jumped to unwarranted conclusions way, way too quick.
Here is the explanation, put simply:
Your Mitochondrial DNA, "mtDNA," is not ordinary DNA.
Unlike ordinary DNA it is not found inside the cell nucleus, but rather inside Mitochondria, which convert food to cell energy.
So, Mitochondrial DNA does not control anything about how we look or how our bodies function.
Those are all under the control of ordinary nucleic DNA.
As a result, your report that human and Neanderthal Mitochondrial DNA differ by 27.2 substitutions is interesting, but conclusive of nothing. Do you know, for examples:
- How many mtDNA substitutions do we find amongst chimpanzees?
Let me suggest that number could easily be dozens. - Or how many substitutions do we find amongst Neanderthals?
Surely unknown today, but again could easily turn out to be dozens.
So the significance of 27.2 substitutions could well evaporate in the "noise" of normal variations within different species.
As I made clear, my argument concerns real DNA, not Mitochondrial DNA.
Studies of real DNA show that human and chimpanzee DNA is about 98.5% identical, if you ignore those pesky indels, but only 95% when you count everything.
Studies of Neanderthal DNA show it more than 99.5% identical to our own.
Again, if we compare "base pairs," which are the chemical building blocks of DNA, and of which our DNA contains about six billion, then the differences between humans and Neanderthals are about 3 million (equals one half of one percent), versus 30 million to 50 million with chimpanzees.
Fossil records show common ancestors for chimps and humans around 5 million years ago, but for Neanderthals and humans less than one million years ago.
By the way, the fossil record shows all-together nearly two dozen different "pre-human" species, including Neanderthals.
Analyses of real DNA differences supports the fossil record.
Point is: your Mitochondrial DNA analysis is interesting, but by itself tells us almost nothing.
wendy1946: "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."
Of course we are related, and there is zero evidence suggesting we are not.
Indeed, in some sense we are related to most, if not all, other life on earth.
For examples: we have the same basic chemistry, the same types of DNA, our bodies function in similar ways, and we find our fossils showing ancestors back to the beginnings of life on earth.
Or put it another way: if we are not related, then nothing is related, and the very word "related" has no meaning. Such suggestions, imho, are ridiculous.
As to whether Neanderthals and Cro-Magnon had a little hanky-panky going on, I have no idea.
Many others have pointed out, that seems all too likely -- but so far DNA evidence for it is slim, at best.