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Despite Homo Sapiens and Neanderthal interbreeding that has been detected using evidence from modern genomes, weak neanderthal genes are gradually being removed by natural selection, according to researchers:
The Neanderthals disappeared about 30,000 years ago, but little pieces of them live on in the form of DNA sequences scattered through the modern human genome. A new study by geneticists at the University of California, Davis, shows why these traces of our closest relatives are slowly being removed by natural selection.
"On average, there has been weak but widespread selection against Neanderthal genes," said Graham Coop, professor in the UC Davis Department of Evolution and Ecology and Center for Population Biology, and senior author on a paper describing the work published Nov. 8 in the journal PLOS Genetics. That selection seems to be a consequence of a small population of Neanderthals mixing with a much larger population of modern humans.
[...] "The human population size has historically been much larger, and this is important since selection is more efficient at removing deleterious variants in large populations," Juric said. "Weakly deleterious variants that could persist in Neanderthals could not persist in humans. We think that this simple explanation can account for the pattern of Neanderthal ancestry that we see today along the genome of modern humans."
Juric I, Aeschbacher S, Coop G (2016) The Strength of Selection against Neanderthal Introgression. PLoS Genet 12(11): e1006340. DOI: 10.1371/journal.pgen.1006340
(Score: 2) by HiThere on Thursday November 10 2016, @06:47PM
This post is all a comment on your last sentence, i.e., "Ragging on neanderthals is fine. Warlike, cannibals, raped to interbreed, etc. Completely acceptable. I don't think that the inverse would be tolerated.".
But the problem is that those characteristics have not been shown to be characteristic of Neanderthals. What has been shown to be characteristic is a different head shape, narrow hips on the women, a difficulty in throwing overhand, etc. These are ways in which Neanderthals appear to have been different from Cro Magnon. More cannibalism has been shown among Cro Magnon, more "warfare" too, etc.....of course, there are also more Cro Magnon sites...
As for the article...yes, weak genes are selected against, and the most important environment of a gene is the other genes around it. Horse teeth don't do a tiger much good. But Cro Magnons were so similar to Neanderthals that almost their entire genome was common between them, and the only way you can identify a Neanderthal gene is if it wasn't useful enough to become dominant in the modern human population. Genes that aren't that useful don't tend to spread rapidly, but those that ARE useful spread rapidly.
E.g.: I have thumbs with what is called a saddle joint. It allows me to flatten my palm more than most people can, but it makes the thumb joint slightly (not much) weaker. I've only found this advantageous when serving volleyball, so I'm reluctant to call this a useful change...OTOH, the joint has never caused me any problems...so it's probably a nearly neutral genetic change, and not really selected for or against. It seems (to me) to neither be spreading through the population nor shrinking in frequency, even though very mild selective pressures can cause this to happen. (N.B.: I'm not an expert in the field, and this was just one minor personal quirk. Perhaps an expert would say that it *is* either increasing or decreasing in frequency.)
To return to your statement, those things they are saying have nothing to do with actual Neanderthals. Those are just snarl noises, and such often don't have any real connection to reality, only a symbolic connection. Like calling someone a snake. You aren't implying reptilian ancestry, but symbolically analogous behavior, to behavior not usually exhibited by the species in question, but rather part of the image many people have of that species.
Javascript is what you use to allow unknown third parties to run software you have no idea about on your computer.