The 'Ice Man' Ötzi has a higher % of Neanderthal genes

[Ichingcarpenter]

Another example is the proportion of Neandertal ancestry. Initially, the proportion of ancestry from Neandertals in living people was argued to be between 1 and 4 percent [3]. That was a model-based estimate that was the best possible under the assumption that Africans have no Neandertal ancestry. We now have a lot more human comparisons, which would make possible a more precise estimate of the mean. I hesitate to provide a new estimate, because we have shown that some Africans have substantial evidence of Neandertal similarity, which throws the baseline for any estimate into question. How much Neandertal ancestry is present in living people must depend on a more complex model of mixture among later populations. The result will still be small (probably less than 6 percent) but understanding this proportion will help us to evaluate when and where Neandertal genes flowed into our populations.



Here's a third example. I haven't written about here yet, but I have been lecturing about it quite widely over the past few months. Earlier this year, the genome of Ötzi the Tyrolean Iceman was reported by Andreas Keller and colleagues [4]. Aaron Sams and I downloaded the data and have been carrying out several different kinds of comparisons. A picture:



http://johnhawks.net/weblog/reviews/neandertals/neandertal_dna/neandertal-ancestry-iced-2012.html

[Confusious]

1. I was reading something the other day

Theey said that those genes might be left over from an ancestor of humans and Neanderthal.

It would make sense if Africans had them, since Neanderthals never made it into Africa, as far as most people know.

[muriel_volestrangler]

3. There can be been a small, slow flow of European or Asian genes to Africa

via the Nile, trading across the Sahara, or Arabic trading down the east coast of Africa.

[Confusious]

6. Occams razor

A common ancestor is a much simpler answer.

Besides, genes don't spread that fast. Otherwise, we'd all be brown.

http://www.smh.com.au/world/science/neanderthals-shared-ancestor-with-humans-20120815-248zp.html

[muriel_volestrangler]

7. But this is about small parts of the genome, not the overall effect

I'm not saying there would be large scale mixing (which you'd need for skin colour to even out everywhere), but the movement of small numbers can transfer a small amount of the genome.

And you might be at the spread of genes:

'Most recent common ancestor' of all living humans surprisingly recent

Chang established the basis of this research in a previous publication with an intentionally simplified model that ignored such complexities as geography and migration. Those precise mathematical results showed that in a world obeying the simplified assumptions, the most recent common ancestor would have lived less than 1,000 years ago. He also introduced the "identical ancestors point," the most recent time -- less than 2,000 years ago in the simplified model -- when each person was an ancestor to all or ancestor to none of the people alive today.

The current paper presents more realistic mathematical and computer models. It incorporates factors such as socially driven mating, physical barriers of geography and migration, and recorded historical events. Although such complexities make pure mathematical analysis difficult, it was possible to integrate them into an elaborate computer simulation model. The computer repeatedly simulated history under varying assumptions, tracking the lives, movements, and reproduction of all people who lived within the last 20,000 years.

These more realistic models estimate that the most recent common ancestor of mankind lived as recently as about 3,000 years ago, and the identical ancestors point was as recent as several thousand years ago. The paper suggests, "No matter the languages we speak or the color of our skin, we share ancestors who planted rice on the banks of the Yangtze, who first domesticated horses on the steppes of the Ukraine, who hunted giant sloths in the forests of North and South America, and who labored to build the Great Pyramid of Khufu."

http://www.stat.yale.edu/~jtc5/papers/CommonAncestors/NatureAncestorsPressRelease.html

3,000 years ago is, for instance, about 2,000 years after the establishment of the Egyptian kingdom, which would be important for flow of genes between the Mediterranean and sub-Saharan Africa. There was also a major movement of population from West Africa to the south - the Bantu expansion - in the last 3,000 years, which could help distribute the smaller proportion of Neanderthal genes from those in possible contact with Mediterranean populations to various African populations.

[Confusious]

8. Yes, but we're talking 1%-4% of DNA

with the average human having 2.5%.(Neanderthal) That would be non-africans and northern africans. southern Africans have almost none.


That study shows we're all related, but by how much? (not that I think "how much" matters, but it does in this discussion)

I'll have 50% of my fathers genes, 25% of my grandfathers, 12.5% of ggg, 9 more generations, and you couldn't even tell we were related. If a generation is 20 years, that's 240 years.

I would have less then .02% of my ggg-etc genes. and I'm a direct decedent.



Honestly, anthropology isn't my forte, I just found the theory of a common ancestor interesting.

[xchrom]

2. Huh. Interesting. Nt

[jody]

4. Genetic research suggests Homo sapiens interbred with Homo neanderthalensis and Denisova hominin to

produce the Euroasians who settled Europe and Asia.

Will science eventually assign a name for the hybrid of Homo sapiens and Homo neanderthalensis?

[Ichingcarpenter]

5. Göbekli Tepe is still 8000 years older than the ice man but

its curious that his genes have a higher concentration of neanderthalensis genes than modern Europeans.. I think the recent debate on where the mix happened is going to be interesting.
The other 'human' Denisova hominin, even adds more to the questions of our origin and what makes us what we are.