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Neanderthal-Human Babies
March 20, 2008 4:24 PM   Subscribe

Any admixture would have to be driven by male Neanderthals. Two years ago we discussed morphological evidence of nontrivial interbreeding. Since then Neanderthal DNA has been examined for genetic support for this model of human evolution, largely contradicting the belief in Neanderthal contribution to modern humanity. Indeed any contribution from the Neanderthal gene pool to the evolution of modern humans might be very rare and indeed it appears that the best candidate gene thus (MC1R) far likely was a result of convergent evolution.

EXCERPT: It is now clear that the level of interbreeding between the two populations, if any, was so low that we are unlikely to find any neutrally evolving Neanderthal alleles in modern populations. However, it is possible that low levels of interbreeding could have led to the adaptive transfer of some alleles between species (introgression). Beneficial alleles can persist in interspecific hybrids even when the hybrids are less fit than either parent population as long as the hybrids are fertile [37]. As hybrids back-cross to a parent population, most introduced alleles will be lost to drift or to negative selection; some beneficial alleles, however, may be maintained in subsequent generations. Claims have been made for adaptive introgression from Neanderthals into populations of modern humans at the microcephalin [38] and the tau [39] loci. Some proponents of the multiregional model have gone so far as to suggest that adaptive introgression was a primary source of beneficial alleles during the evolution of modern humans [40]. While we regard this latter idea as unsupported by the available Neanderthal and human genome sequences, it is worth considering the possibility that a very limited amount of adaptive introgression has occurred.

MC1R is a good a priori candidate for adaptive introgression. It is thought that light skin is favored in Europe as a compromise between the need for vitamin D synthesis and the need to prevent folate photolysis, both caused by UV radiation [41]. Several genes affecting skin color are known to have been positively selected in European populations [21,22], though studies of MC1R evolution have come to different conclusions [22,42,43]. Jolly has pointed out that the easiest way for early modern humans entering Europe to evolve light skin would be to acquire the necessary genes from Neanderthals rather than to evolve them de novo [44]. If the low-activity MC1R variant is positively selected in Europe, then MC1R presents a good opportunity to test for evidence of adaptive introgression from Neanderthals to modern humans. However, although Neanderthals and modern Europeans share a low-activity MC1R phenotype, the genotype is different (see above), which argues against significant adaptive introgression. The hypothesis could be tested more rigorously using Neanderthal sequence from other loci affecting skin color with a clearer signal of positive selection in Europeans.
posted by wantwit (19 comments total) 3 users marked this as a favorite

 
From the first link: "Access to the full text of this article requires a subscription (the abstract is freely accessible)"
posted by aubilenon at 4:45 PM on March 20, 2008


Does it make me a speciest that I'm relieved my ancestors never bread with those DIRTY NEANDERTHALS?
posted by norabarnacl3 at 4:57 PM on March 20, 2008 [1 favorite]


A quick Google Scholar search turned up a similar study which is freely available.
posted by aheckler at 5:00 PM on March 20, 2008


So, does this make my Neanderthal-on-human porn collection "furry/furvert" or "barnyard sex"?
posted by KokuRyu at 5:03 PM on March 20, 2008


KokuRyu, it depends during which time period it was set in.
posted by wantwit at 5:16 PM on March 20, 2008


The existence of uncertainty about this conclusively proves creationism.
posted by Pope Guilty at 5:21 PM on March 20, 2008


My father always told me that Neanderthals were good time girls, and you can sow your wild seeds with them, but they're not the sort a proper man marries.
posted by Astro Zombie at 5:33 PM on March 20, 2008 [2 favorites]


Those Neanderthals who lay down with the daughters of man were smote by Jesus himself, and their offspring were hideous winged demons who burst out of the womb, blinding all they touched and leaving behind so-called "fossils" when they were defeated with holy water.

So wake me up when they do some real research, like whether or not Jesus was riding a dinosaur when he smote them. If I were to hazard a guess, he was.
posted by Krrrlson at 5:45 PM on March 20, 2008 [1 favorite]


So I guess this explains why Esau was so hairy. Rebekah must have been getting some cave man on the side. She did always like her men tall, dark and mousterian.
posted by Pollomacho at 5:55 PM on March 20, 2008 [1 favorite]


So, like, then africans are more human than europeans? Us honkies are actually half breeds that share a lineage with a failed species of human?

This should throw the white supremist movement out of whack. I think this should be adressed at the next white peoples meeting. Maybe the Nation of Islam is right...
posted by The Power Nap at 6:00 PM on March 20, 2008 [1 favorite]


Everything I need to know about this subject, I learned from reading "Clan of the Cave Bear" when I was twelve.
posted by padraigin at 6:09 PM on March 20, 2008 [2 favorites]


[fileshare to article removed - we can't really do that here]
posted by jessamyn at 6:15 PM on March 20, 2008


If the dumpy, prole Neanderthals actually looked to the gracile, slinky, anorexic-supermodel (for the time) Cro-Magnons like those Neanderthal reconstructions look to us, it would have been a haaard sell.


> I think this should be adressed at the next white peoples meeting.

We went over and over that at the last meeting. The descended-from-Angels partisans outvoted the descended-from-Benevolent-White-Spacefaring-Aliens crowd by a slim margin. We are descended from Angels. (Not very far descended either, come to that.)
posted by jfuller at 6:51 PM on March 20, 2008


Weren't Neanderthals super strong and bigger brained?

Did either group use intoxicants that might have helped members of one group to see members of the opposite sex from the other group in more attractive terms? It's hard to believe Neanderthals and Cro-Magnon weren't able to cross fertilize since even cattle from the Old World and buffalo from the New World have been known to cross breed and produce fertile offspring.
posted by millardsarpy at 7:19 PM on March 20, 2008


does this make my Neanderthal-on-human porn collection "furry/furvert" or "barnyard sex"?

KokuRyu, as best as I can tell from looking through your windows, that's just Ron Jeremy.

And of course Ron Jeremy isn't a neanderthal. He's a homo erectus. Or is that Jeff Stryker?
posted by ROU_Xenophobe at 7:19 PM on March 20, 2008


I've heard that there is insufficient statistical power from the sequenced putative Neanderthal DNA to distinguish it from contaminant human DNA. All of the observed variations can be explained as sequencing error. If that's the case, all of this analysis will be somewhat speculative until enough Neanderthal DNA has been obtained and sequenced to establish statistically significant variation from human allele frequencies.
posted by Coventry at 7:40 PM on March 20, 2008


Now we know how the Republicans will swiftboat Obama.
posted by oddman at 7:40 PM on March 20, 2008


ENGLISH MOTHERFUCKER, DO YOU SPEAK IT?!

/Samuel L. Jackson
posted by papakwanz at 9:06 PM on March 20, 2008


Coventry, that's not entirely true although there is definitely some truth to that. I've actually spoken with one of the authors on the Neanderthal genome projects currently in the works and you don't just look at the differences in sequence but the age of the sequence which can be reliably estimated. Any human DNA on bones that are morphologically Neanderthal will have significantly less DNA damage associated with the sequence AND tend to be present in larger fragments. For example most of the reads that are reliable Neanderthal sequences are very short <100 bp AND have a high degree of detectable DNA degradation.
posted by wantwit at 10:06 PM on March 20, 2008


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