Science a GoGo's Home Page Forums General Discussion General Science Discussion Forum No Neanderthal Human interbreeding?

Phys.org has a story about new research that suggests that the much touted interbreeding between Neanderthals and Modern Humans didn't happen after all. I see that it is on the front page of SAGG too. Basically the authors of the paper that is being reported on think that the similarity in part of the DNA of Neanderthals and Modern Humans comes from the fact that they shared an ancestor. Obviously it is true that they shared an ancestor, but of course their work is not going to be accepted immediately. In fact the following quote from the reports makes a statement that I'm not sure I understand.


My problem and I realize that it may just be my problem, is that I see no reason why all the moderns that migrated from Africa would be the ones with the DNA that matched the Neanderthal DNA. Did somebody do a DNA test and refuse a passport to any body that didn't have Neanderthal DNA?

Bill Gill

Relatively easy to test which is right provided mitochondrial DNA for the groups is available.

http://en.wikipedia.org/wiki/Genealogical_DNA_test

=> A direct maternal ancestor can be traced using mtDNA. MtDNA is passed down by the mother unchanged, to all children. A perfect match is found to another person's mtDNA test results indicates shared recent ancestry. More distant matching to a specific haplogroup or subclade may be linked to a common geographic origin.

Well, this new idea is based on "new and improved" DNA testing/processing. I expect that there will be quite a big of back and forth on it before there comes to be a consensus. And of course the MtDNA test was the first that was run, and based on that we don't have any Neanderthal genes. The mixture was discovered on whole genome testing.

They are doing a lot of good things with DNA, but there is still a lot to be learned, and for a while in the future there will be all kinds of conflicting interpretations.

Bill Gill

Bill have you got a link to the article physics org site links only the pnas site.

From what I am reading it looks like they just built a model and ran the model forward to see what would happen.

I am not sure they did any new genetics.

Being a computer modeller I am interested in what they did under the hood so to speak because I have issues with it as it is reported in the article.


EDIT: I see one of the comments on PNAS has already worked it out

"Manica & Eriksson's hypothesis is easily disproven. If the "Neandertal genes" were actually the result of genetic similarities between Neandertals and ancient North African modern humans, then those genes would still be visible in North Africa today. The fact that they aren't, except in Asian-descended Arabs, is evidence against the hypothesis. Also, those genes would have slowly diffused southward over the last 320,000 years and some trace should show up in southern African populations (decreasing the further south you go), but the genes are completely absent."

You can't argue the genes are fluidly mobile in the first instance and not mobile at all there after.

If this is peer reviewed the reviewer should be sent back to science modelling 101 coarse.