North Africans Carry Neanderthal DNA

[Tomk80]

sfs told me that gene among all humans could be homogenized (?) in a few tens of thousands of years. (Right? sfs?)

If so, what are you saying?

It would seem to me that this is only the case if there is a strong gene flow between all populations, which is currently the case. But this has only been so for the last hundred years or so. Gene flow between populations was more restricted in the past.

 

[Tomk80]

But they may not intelligently be modern humans. If so, they are NOT humans.

They were, regardless of how you want to arbitrarily show your ignorance.

And regardless if they were "human" or not, there was interbreeding between Neanderthals and homo sapiens.

 

[Tomk80]

If so, why not, for example, southern Africans also carry the DNA of Neanderthals?

Because for hybridization to occur they would have to be in the same area. Kind of hard to hybridize if you're not at the same location.

 

[Loudmouth]

If so, why not, for example, southern Africans also carry the DNA of Neanderthals?

I don't think neanderthal DNA in sub-saharan africans has been entirely ruled out. I would strongly suspect that they do find some.

Again, why is this confusing? Do you understand that species can form hybrids and still be separate speices?

 

[Loudmouth]

But they may not intelligently be modern humans. If so, they are NOT humans.

So people with Down Syndrome are not human?

 

[Notedstrangeperson]

If so, why not, for example, southern Africans also carry the DNA of Neanderthals?

I don't think neanderthal DNA in sub-saharan africans has been entirely ruled out. I would strongly suspect that they do find some.

It seems unlikely they will find Neanderthal DNA in sub-saharan Africans since there is no evidence (so far) that Neaderthals ever lived in Africa.

Of course, there is no evidence that they lived in Asia, or Australia, or the Americas either, but the modern humans who live there today still carry their DNA. But that is probably because they interbred with Neanderthals from the Middle East before spreading to the rest of the world, bringing their newly-accquired Neanderthal genes with them.

My guess would be that North Africans carry Neanderthal DNA because they represent a group which left Africa and later returned.

In parts of the world where modern humans (i.e. we) and Neanderthals lived close together, they may have interbreeded. This was in Europe and Asia. That way Neanderthals contributed genetic material to Europeans and Asians and possibly north-Africans. They did not contribute genetic matieral to Sub-Saharan Africans (for example), because Neanderthals did not live there.

But human interbred. Should then the Neanderthals DNA spread to all humans?

We know that north Africans do not carry Neanderthal DNA because of race-mixing from Europeans or Asians because they looked at a specific area of the genome which dates back to the pre-Neolithic (over 10,000 years old) - long before modern civilisations invaded Africa.

 

[juvenissun]

Originally Posted by juvenissun

sfs told me that gene among all humans could be homogenized (?) in a few tens of thousands of years. (Right? sfs?)

I'm afraid I don't remember exactly what I said. Ask a specific question and I'll answer it to the best of my ability.

I don't remember it exactly either. But did I say the right thing here?

 

[juvenissun]

It would seem to me that this is only the case if there is a strong gene flow between all populations, which is currently the case. But this has only been so for the last hundred years or so. Gene flow between populations was more restricted in the past.

You may be right. But I could not evaluate the rate before the modern time. I would like to see the rate vs. time curve, though.

 

[juvenissun]

They were, regardless of how you want to arbitrarily show your ignorance.

And regardless if they were "human" or not, there was interbreeding between Neanderthals and homo sapiens.

That is a good point. Thanks.

 

[juvenissun]

I don't think neanderthal DNA in sub-saharan africans has been entirely ruled out. I would strongly suspect that they do find some.

Again, why is this confusing? Do you understand that species can form hybrids and still be separate speices?

I don't know. I forgot. Sorry.

 

[juvenissun]

So people with Down Syndrome are not human?

Their parents are humans. So are they.

 

[juvenissun]

It seems unlikely they will find Neanderthal DNA in sub-saharan Africans since there is no evidence (so far) that Neaderthals ever lived in Africa.

Of course, there is no evidence that they lived in Asia, or Australia, or the Americas either, but the modern humans who live there today still carry their DNA. But that is probably because they interbred with Neanderthals from the Middle East before spreading to the rest of the world, bringing their newly-accquired Neanderthal genes with them.

My guess would be that North Africans carry Neanderthal DNA because they represent a group which left Africa and later returned.


We know that north Africans do not carry Neanderthal DNA because of race-mixing from Europeans or Asians because they looked at a specific area of the genome which dates back to the pre-Neolithic (over 10,000 years old) - long before modern civilisations invaded Africa.

Could this process be dated? sfs?

 

[sfs]

Could this process be dated? sfs?

Yes. See "The date of interbreeding between Neandertals and modern humans", by Sriram Sankararaman, Nick Patterson, Heng Li, Svante Pääbo, David Reich, here.

Abstract:
"Comparisons of DNA sequences between Neandertals and present-day humans have shown that Neandertals share more genetic variants with non-Africans than with Africans. This could be due to interbreeding between Neandertals and modern humans when the two groups met subsequent to the emergence of modern humans outside Africa. However, it could also be due to population structure that antedates the origin of Neandertal ancestors in Africa. We measure the extent of linkage disequilibrium (LD) in the genomes of present-day Europeans and find that the last gene flow from Neandertals (or their relatives) into Europeans likely occurred 37,000-86,000 years before the present (BP), and most likely 47,000-65,000 years ago. This supports the recent interbreeding hypothesis, and suggests that interbreeding may have occurred when modern humans carrying Upper Paleolithic technologies encountered Neandertals as they expanded out of Africa."

I don't know if they've submitted the paper to a journal for publication.

 

[juvenissun]

Yes. See "The date of interbreeding between Neandertals and modern humans", by Sriram Sankararaman, Nick Patterson, Heng Li, Svante Pääbo, David Reich, here.

Abstract:
"Comparisons of DNA sequences between Neandertals and present-day humans have shown that Neandertals share more genetic variants with non-Africans than with Africans. This could be due to interbreeding between Neandertals and modern humans when the two groups met subsequent to the emergence of modern humans outside Africa. However, it could also be due to population structure that antedates the origin of Neandertal ancestors in Africa. We measure the extent of linkage disequilibrium (LD) in the genomes of present-day Europeans and find that the last gene flow from Neandertals (or their relatives) into Europeans likely occurred 37,000-86,000 years before the present (BP), and most likely 47,000-65,000 years ago. This supports the recent interbreeding hypothesis, and suggests that interbreeding may have occurred when modern humans carrying Upper Paleolithic technologies encountered Neandertals as they expanded out of Africa."

I don't know if they've submitted the paper to a journal for publication.

Are they doing the similar to people in other continents? It seems the resolution might not be good enough to identify the migration. Right?

 

[sfs]

Are they doing the similar to people in other continents? It seems the resolution might not be good enough to identify the migration. Right?

The resolution isn't good enough to know exactly when in the Out-of-Africa migration the interbreeding took place, but the dates they've got make it likely that it happened before Europeans got to Europe. I don't know if they've tried to do the same analysis with Asians; I can ask when I see one of the authors. (I don't know that there's anywhere else for them to look: the Americas almost certainly would show the same interbreeding that occurred in Asia, native Australians are difficult to study for, well, historical reasons. Maybe New Guineans.)

 

[Loudmouth]

Their parents are humans. So are they.

We also share a common ancestor with neanderthals, so does that make them human?

 

[juvenissun]

We also share a common ancestor with neanderthals, so does that make them human?

Again, we need to define "human" first. Skeletal data are not good enough. DNA data are not good enough either. The author of the OP should have a lot to say about this issue.

 

[juvenissun]

The resolution isn't good enough to know exactly when in the Out-of-Africa migration the interbreeding took place, but the dates they've got make it likely that it happened before Europeans got to Europe. I don't know if they've tried to do the same analysis with Asians; I can ask when I see one of the authors. (I don't know that there's anywhere else for them to look: the Americas almost certainly would show the same interbreeding that occurred in Asia, native Australians are difficult to study for, well, historical reasons. Maybe New Guineans.)

Thanks.

(too bad I can not give harder questions).