Ancient human genomes suggest three ancestral populations for present-day Europeans

[Grubbe]

Since all homo sapiens sapiens now have either Neanderthal or other archaic admixture it is, imo, and as I said upthread, a "human" issue, not an "ethnic" one.

Have they found other archaic admixture in Africans, that non-Africans don't have? Because they still haven't found any Neanderthal or Denisovan DNA in Africans?

 

[Angela]

Have they found other archaic admixture in Africans, that non-Africans don't have? Because they still haven't found any Neanderthal or Denisovan DNA in Africans?

I don't want to de-rail this thread, so I would just suggest going to dienekes.blogspot.com and using the search engine there. It's pretty inactive now, but it has a great and well organized archive. I remember a lot of papers and posts there discussing archaic admixture in Africa.

These are just two:

[h=1]http://dienekes.blogspot.com/2014/06/an-older-layer-of-eurasian-admixture-in.html[/h] [h=1]http://dienekes.blogspot.com/2012/07/new-evidence-for-archaic-admixture-in.html[/h]

 

[Angela]

The amount of whole Neanderthal genome floating around is about 20%. It means that my 2% of Neanderthal might be totally different from next person's 2%.

Totally different? I would doubt that is frequently the case. The overlap in terms of the remaining Neanderthal genes even between Europeans and East Asians is marked, even though our lineages diverged tens of thousands of years ago.

It also means that this surviving 29% of Neanderthal DNA is completely interchangeable and compatible with Sapiens DNA

That isn’t at all my reading of Sankararaman et al (The authors included Paabo, Patterson and Reich)

The genomic landscape of Neanderthal ancestry in present-day humans

http://www.nature.com/nature/journal/v507/n7492/full/nature12961.html

“Regions that harbour a high frequency of Neanderthal alleles are enriched for genes affecting keratin filaments, suggesting that Neanderthal alleles may have helped modern humans to adapt to non-African environments. We identify multiple Neanderthal-derived alleles that confer risk for disease, suggesting that Neanderthal alleles continue to shape human biology.”

Not all the negatively adaptive Neanderthal alleles have been ejected through purifying selection. If they had been, they wouldn’t continue to shape human biology through diseases like diabetes, lupus, cirrhosis, Crohn’s disease, and according to some studies, rheumatoid arthritis, Hepatitis C, small cell lung cancer, various heart and circulatory ailments, neurological disorders, long term depression etc.

Future papers may paint a different story, but this seems to be the latest research on the subject, and it doesn’t seem to be very controversial.

 

[LeBrok]

Totally different? I would doubt that is frequently the case. The overlap in terms of the remaining Neanderthal genes even between Europeans and East Asians is marked, even though our lineages diverged tens of thousands of years ago. That isn’t at all my reading of Sankararaman et al (The authors included Paabo, Patterson and Reich)

I can't find the study at the moment but this is the article that claims that, with name of lead research and University.
http://www.livescience.com/42933-humans-carry-20-percent-neanderthal-genes.html

“Regions that harbour a high frequency of Neanderthal alleles are enriched for genes affecting keratin filaments

suggesting that Neanderthal alleles may have helped modern humans to adapt to non-African environments. We identify multiple Neanderthal-derived alleles that confer risk for disease, suggesting that Neanderthal alleles continue to shape human biology.”

Not all the negatively adaptive Neanderthal alleles have been ejected through purifying selection. If they had been, they wouldn’t continue to shape human biology through diseases like diabetes, lupus, cirrhosis, Crohn’s disease, and according to some studies, rheumatoid arthritis, Hepatitis C, small cell lung cancer, various heart and circulatory ailments, neurological disorders, long term depression etc.

In all these cases probability of disease is rising especially in older age, but they are not eminent. Considering length of human life in the past, these maladies carrying genes were not that destructive. Otherwise they would have been weeded out already. We are just "unlucky" to live too long, and experience full Neanderthal heritage.

In complicated systems or organisms as humans, many genes have dual or multiple functions. Increase risk for a certain disease is compensated by beneficial action on behave of organs or systems. Sickle cell anemia pops as fast example.
So perhaps these increased predispositions to sickness inherited from Neanderthal might be compensated by better adaptation to cold and new diet, from action of same genes.

 

[Grubbe]

I don't want to de-rail this thread, so I would just suggest going to dienekes.blogspot.com and using the search engine there. It's pretty inactive now, but it has a great and well organized archive. I remember a lot of papers and posts there discussing archaic admixture in Africa.

These are just two:

http://dienekes.blogspot.com/2014/06/an-older-layer-of-eurasian-admixture-in.html

http://dienekes.blogspot.com/2012/07/new-evidence-for-archaic-admixture-in.html

Thanks again.