Short IBD segments shared between Humans, Neanderthals and Denisovans in Africa and Eurasia

[Argang]

To test for an enrichment of Denisova, Neanderthal or Archaic matching segments they used Fisher’s exact test for count data. The "Admixed Americans" they refer to are various South American nationals. For other populations it seems that Denisovan and Neanderthal segments grow in number with distance to Africa (Africans-> Europeans -> East Asians).

Denisovans: Amerindians seem to have more than Europeans which would explain the result for "Admixed Americans". Denisovan segments peak in South Chinese among the tested populations, which makes sense since they are closest to Papuans who have highest Denisovan levels in the planet. Africans have the least Denisovan. No visible geographical clines in Europe.

Spoiler!

Neanderthals: Besides the main cline of Africans to non-Africans, there's a secondary cline with increasing amount of Neanderthal IBD towards north. Africans have the least segments, and "Admixed Americans" have less than Europeans.

Spoiler!

We analyze the sharing of very short identity by descent (IBD) segments between humans,
Neandertals, and Denisovans to gain new insights into their demographic history. Short IBD
segments convey information about events far back in time because the shorter IBD segments are,
the older they are assumed to be.

A DNA segment is identical by state (IBS) in two or more individuals if they all have identical nucleotide sequences in this segment. An IBS segment is
identical by descent (IBD) in two or more individuals if they have inherited it from a common ancestor, that is, the segment has the same ancestral origin in these individuals.

http://biorxiv.org/content/biorxiv/e...03988.full.pdf

[Longbowman]

Yes, the Mongoloids are the most non-Sapiens of the three primary races. Interesting.

[Argang]

Yes, the Mongoloids are the most non-Sapiens of the three primary races. Interesting.

I think Mbuti pygmies are the top contender for purest Homo Sapiens on the planet now that there's evidence of West Eurasian in the Khoisan.

[Longbowman]

I think Mbuti pygmies are the top contender for purest Homo Sapiens on the planet now that there's evidence of West Eurasian in the Khoisan.

Southeast Asians are the least sapiens.

[Kale]

I thought pygmies inherited a couple percent from some unknown species?

[Argang]

I thought pygmies inherited a couple percent from some unknown species?

I think the idea was that most SSA groups did. It's not really researched yet, since no one has found remains of such a hominid.

[Kale]

Rhodesia?

[Longbowman]

Rhodesia?

Old name for Zimbabwe.

[Kale]

Old name for Zimbabwe.

Old name for buttcheeks.

[Longbowman]

Old name for buttcheeks.

What