Breeding with Neanderthals helped humans go global

[kpete]

Source: News Scientist

Breeding with Neanderthals helped humans go global

16 June 2011 by Michael Marshall
Magazine issue 2817.

WHEN the first modern humans left Africa they were ill-equipped to cope with unfamiliar diseases. But by interbreeding with the local hominins, it seems they picked up genes that protected them and helped them eventually spread across the planet.

..............

Parham points out that because Neanderthals and Denisovans had lived outside Africa for over 200,000 years by the time they encountered H. sapiens, their HLAs would have been well suited to local diseases, helping to protect migrating H. sapiens too.

While only 6 per cent of the non-African modern human genome comes from other hominins, the share of HLAs acquired during interbreeding is much higher. Half of European HLA-A alleles come from other hominins, says Parham, and that figure rises to 72 per cent for people in China, and over 90 per cent for those in Papua New Guinea.

This suggests they were increasingly selected for as H. sapiens moved east. That could be because humans migrating north would have faced fewer diseases than those heading towards the tropics of south-east Asia, says Chris Stringer of the Natural History Museum in London.



Read more: http://www.newscientist.com/article/mg21028174.000-breeding-with-neanderthals-helped-humans-go-global.html

[Honeycombe8]

1. I wonder if this means the theory that Neanderthals became extinct and didn't interbreed....

with H. sapiens is proven false? That was the most common theory I've read. Although how any scientist can know it either way confounds me.

It's very interesting to ponder, though.

[kpete]

2. proof?

The publication of the Neanderthal genome last year offered proof that Homo sapiens bred with Neanderthals after leaving Africa. There is also evidence that suggests they enjoyed intimate relations with other hominins including the Denisovans, a species identified last year from a Siberian fossil.
http://www.nature.com/nature/journal/v464/n7290/full/nature08976.html

[colorado_ufo]

18. Yes. It means that , as a species,

they literally f_cked themselves to death.

[kenfrequed]

20. uhm not quite.

It is more that they assured their genes would be passed on in one manner or another which is pro survival. Had none of their genetic material survived they would have pruded themselves to an actual genetic death. I believe the mistake is to mistake the various subspecies for a static individual state rather than a dynamic pool only barely seperated and having emphasized traits for survival in particular environs they were readopted with these empasized states put towards survival for a broader species.

[Spider Jerusalem]

19. The reason for that theory...

was that modern human mitochondrial and Y-chromosome DNA diverged from Neandertal DNA to the point where there was no chance of any known modern human Y-chromosome or mitochondrial DNA lines descending from Neandertals. Which was taken as evidence that there was no interbreeding. Sequencing of the Neandertal genome has shown that there was interbreeding...which means there's no direct male line from any modern humans to Neandertals, as Y-DNA is passed from father to son, and no direct line back to a Neandertal female either, as mitochondrial DNA are passed from mother to child...which further means those genetic traces were lost through the direct male and female lines dying out for one reason or another.

[L. Coyote]

36. Old history. Recent studies of human genome shows we are part Neanderthal.

[L. Coyote]

37. If Republicans accuse a Democrat's ancestors of breeding with a Neanderthal

would they have to resign? :rofl:

[awoke_in_2003]

39. recent observations of my fellow man....

support this :)

[47of74]

3. I could say something here....

...but I guess I best not.

[entanglement]

4. Breeding with Netherlanders?

:evilgrin:

[Rincewind]

12. Better than

breeding with Ned Flanders.

[dawg]

33. Stupid Sexy Flanders!

Crap! The first one that I posted was sexier than I intended.

[xchrom]

5. Recommend

[existentialist]

6. This is a good story and a good post, but

Does it really belong in the latest breaking news forum?

[DBoon]

7. This is at least 50,000 years old

hardly late breaking news

[truebluecollar]

10. Well, it helps explaining why

there are Republicans.

[JI7]

21. yes it does

[geomon666]

8. Are...are they saying inbreeding is a good thing?

:hide:

[Iliyah]

9. LOL

the creationists will completely ignore this 24/7

[bhikkhu]

15. Actually, yes, that is one of the bigger messages

Simply put, interbreeding fosters robust disease resistance and better overall health.

"Genetic Purity", whatever else we think about it (and to the extent that it even exists), leads to homogeneous populations susceptible to extinction through disease. Disease organisms evolve constantly, and the best defense a population has is diversity. In many historical cases, genetic homogeneity of a population combined with a new form of pathogen has led to 95% death rates, and the extinction of cultures.

Europe has long been a motley bunch living in miasmal soups of cities, but that gave them a big advantage in the early age of exploration. Of course, they assumed it was "god's will" and so forth, but that's all a very long story...

[mckara]

11. That Explains My Ex-Wife...

:rofl: :rofl:

[Poll_Blind]

13. There ain't 7 billion people on this Earth 'cause people are picky about screwin'

THAT'S for sure.

PB

[harmonicon]

16. haha!! +1 nt.

[JCMach1]

22. Did this coincide with the invention of alcohol by Homo Sapiens?

[knitter4democracy]

40. The Doctor would agree with you (as would Capt. Jack). nt

[Odin2005]

14. Well, that explains my thick brow.

[greyl]

17. Headline should specify "modern" humans, because Neanderthals are also a human species. nt.

[Prometheus Bound]

25. Yes, I found that headline very strange.

[tclambert]

23. It's all the fault of teenage girls attracted to "bad" boys their parents hated.

"But, sweetie, he's a Neandertal!"

"Mo-om, so what if he looks funny and walks funny and smells funny? Maybe I love him!"

"I'll disown you!"

"Right, Dad, and you call him a caveman. Well we can make it on our own! Oh, BTW, I hate you both."

[Blandocyte]

24. and led to the birth of the republican party

[tabasco]

26. Hey baby.

Once you go 'thal,
You get it all!

[happyslug]

27. Much ado about nothing, other explanations are more probable.

At the present time, no COMPLETE sequence of DNA from a Neanderthals has been found, partial DNA has been (And complete Mitochondria DNA), but not Nuclear DNA (Nuclear DNA, which is from BOTH parents, degrades faster then Mitochondria DNA, which you get only from your mother). Thus this report is based on such partial reconstruction of the DNA sequence.

One of the problem with dealing with modern humans and Neanderthals interbreeding is to what extent. As to women present study of the DNA found today in living Humans indicate we all are decedent from one woman that lived 100,000 to 150,000 years ago (This women is sometime referred to a "Eve", as to males, the evidence is less clear, at least four or five males could be a "Adam", but the evidence from DNA is less clear on male parentage). This cut out any FEMALE Neanderthals and thus Mitochondria DNA is of no help.

another problems with Neanderthals interbreeding with Modern Humans, is the actual DNA sequence, did Neanderthals have the same number of genes as modern humans, or were the genes close enough to interbreed, but the product of that interbreeding sterile? The best know example of this is Horses, Donkeys and Mules. Horses and Donkeys have different number of genes, but they are close enough to permit interbreeding to produce mules. Mules are generally sterile (i.e. incapable of breeding). In such cases you can NEVER have a movement of genes from one species to the other, while the Mules is the product of such interbreeding, the Mule itself can not reproduce.

Now, in some cases mules can reproduce. These are rare, but do occur. If they breed with a Horse, either a Horse is produced or another Mule. If a Donkey is breed with the Mule, the product is either anther Mule or a Donkey. If this continues, you end up with Horses or Donkeys, not mules after several generations (This last sentence is theory only, no one to my knowledge has done such breeding over several generations do to the high level of sterility in mules). Some genes transfer could occur, but it would be minor (This is being done with the American Chestnuts to breed Chestnut blight resistance into the American Chestnut from the Chinese Chestnut, it has been a work in process for over 50 years, most results have been American Chestnuts WITHOUT the resistance, or the much shorter Chinese Chestnut. Only with careful research, i.e. breeding blight resistance Chestnuts that have the most American Chestnut uncharacteristic, over the generations, recently it is believed the goal has been achieved, but after 50 years of such breeding).

It is possible that the 5-6 % of Modern Human DNA is the product of interbreeding with Neanderthals, but that 5-6% difference may be from other sources (including new mutations of the otherwise normal genes of Modern Humans). Thus, I can NOT cut out the possibility of such interbreeding producing the 5-6% DNA claim being made, on the other hand it is possible that is from normal rate of mutations within Human Genes. I need more then this snippent to make a determination of that fact, it is interesting but no where near conclusive as to Neanderthal DNA being in modern Humans.

[harmonicon]

34. I don't see how you can argue that newer mutations could be the cause...

of non-african humans sharing neandertal genes. That would really be quite a shock if standard mutation rates just happened to give us genes which neandertals, but not sapiens had prior to 30k years ago, and that these mutations would only exist in populations outside of Africa. That is, neandertal genetic contributions to non-african human genomes is almost a 100% certainty.

More over, you seem to be assuming that we're dealing with multiple species here, but that's just speculation. There is another argument that all genus homo "species" could be grouped as one, at least since homo erectus.

[L. Coyote]

38. You need to take Anthropology 101, to correct yourself.

[Yavin4]

28. Neanderthals?

[Withywindle]

30. Yo mama was soooooooooooooooo easy...

even a caveman could do her!

[ItNerd4life]

29. So Democrats did actually breed with Republicans? Who knew? nt

[yesphan]

32. They did..........

[and-justice-for-all]

31. Neaderthal traits are visible in the repukes and teahadist..nt

[formercia]

35. Someone wrote a song about it:

http://www.youtube.com/watch?v=9NF5XU-k2Vk