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I've read years ago that 8% of all Asian men and thus 0.5% of all men would be descendant of Genghis Khan.

Is there any truth to this? Or was this some trick to get their paper published?

Citation of the original paper: Zerjal, Tatiana et al. "The genetic legacy of the Mongols." American journal of human genetics vol. 72,3 (2003): 717-21. doi:10.1086/367774. PDF

Carra
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    "Trick to get their paper published" - One would expect from proper peer review that gimmicky exaggerated claims would not get published. A simple "order of magnitude" calculation that would take into account the total number of earth's inhabitants at a given time allows you to roughly estimate how many ancestors there are. – Lagerbaer Aug 13 '11 at 00:28
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    I cannot comment the exact genetic lineage of Genghis Khan, but a few years ago I read this piece from John Allen Paulos http://abcnews.go.com/Technology/story?id=2019650&page=1 . He claims that a genetic line(Jesus for shock value) either dies out fast in a few generations or grows a lot. So if there are descendants of the mongol ruler there will be lots of them. So it is plausible. – Daniel Iankov Aug 13 '11 at 01:06
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    @Lagerbaer “One would expect from proper peer review that gimmicky exaggerated claims would not get published.” – You wish! Alas, it’s all too common. Authors try to pimp their papers by whatever way possible to get into a high-profile journal and all too often reviewers don’t care enough to filter this out. – Konrad Rudolph Feb 15 '12 at 23:09
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    There was a [segment on QI](http://www.comedy.co.uk/guide/tv/qi/episodes/7/10/) which states: "Mathematically speaking, everyone in Europe is related to Charlemagne. This is because everyone has two parents, four grandparents, eight great-grandparents and so on. By the time you get to the 13th century, you have more direct ancestors than have ever been human beings - about 80 billion." –  Oct 04 '12 at 20:24
  • The claim they make in the paper is a lot stronger than just being descendants. They claim that 8% of asians are descendants of Genghis Khan through the male lineage. That means in practice that they claim that >90% of human are descendents of Genghis Khan if you would say that you are a descendent of your grandmother. – Christian Oct 05 '12 at 09:38
  • ... and, also, of a King of France!?! :) – paul garrett Aug 29 '22 at 03:14

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I love it when questions contain the research for their own answer.

The paper describes a particular set of genes:

We have identified a Y-chromosomal lineage with several unusual features. It was found in 16 populations throughout a large region of Asia, stretching from the Pacific to the Caspian Sea, and was present at high frequency: ∼8% of the men in this region carry it, and it thus makes up ∼0.5% of the world total

It analyses it current populations statistically, using a couple of approaches to conclude:

The origin was most likely in Mongolia, where the largest number of different starcluster haplotypes is found (fig. 1). Thus, a single male line, probably originating in Mongolia, has spread in the last ∼1,000 years to represent ∼8% of the males in a region stretching from northeast China to Uzbekistan.

It considers, and shows evidence to refute, a number of possible causes of this, e.g.

Could biological selection be responsible? Although this possibility cannot be entirely ruled out, the small number of genes on the Y chromosome and their specialized functions provide few opportunities for selection (Jobling and Tyler-Smith 2000). It is therefore necessary to look for alternative explanations.

It searched for confirmatory evidence by looking at a population that are (putatively) direct male line descendents of Khan.

Looking through Google Scholar, I can see no examples of refutation, but many others citing their results positively (e.g.). The paper was published in a reputable peer-reviewed journal, and contains a number of authors from prestigious institutions that are working within their areas of expertise, so the idea that it might be exaggerated for publication is unlikely.

It appears to have a robust result, that it seems reasonably to provisionally accept unless counter evidence is produced.

Oddthinking
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    Note: if the research is done with Y chromosome only, it limits descendency line to male only. Such limiting leads to interesting statistical effects, like http://en.wikipedia.org/wiki/Y-chromosomal_Adam. – Suma Aug 15 '11 at 09:09
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    @Suma, could you please elaborate? I skimmed that Wikipedia article, and didn't see any "interesting statistical effects" (unless you mean the concept of Y-chromosomal Adam, itself, which hardly affects the legitimacy of this paper.) – Oddthinking Aug 15 '11 at 10:08
  • Yes, I mean the concept itself. The "interesting statistical effect" is that whenever you take a feature which is inherited by a male only or female only line, you will always end with something like a "single common ancestor" (Chromosomal Adam, Mitochondrial Eve) when looking far enough into the past. This is because such features can only disappear (and never appear again). Whenever the populations meet and breed, you will see something like this. That said, I admit I did not read the paper and I do not know how this affects its validity. – Suma Aug 16 '11 at 10:41
  • @Suma, this is basically the subject of the paper - whether the Chromosomal Adam lineage for this particular sequence passes through Khan. It doesn't affect its validity so much as form the essence of it. – Oddthinking Aug 16 '11 at 12:36
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    It only establishes that 8% are descendent of Mongol folks that were related by paternal lineage to an ancestor of Genghis Khan--- not that they are descended from him personally. For this, you would need Y markers unique to his specific descendents, and look for their prevalence, and this is exceedingly difficult. – Ron Maimon Oct 07 '12 at 16:55
  • @Ron: That's a good point. I tried to go back to the paper to see if they addressed it, but the link is broken. :-( – Oddthinking Oct 08 '12 at 01:01
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    @Oddthinking, it looks like "The Amplitwist" just repaired the link. I found this: "*The available evidence suggests that it was carried by Genghis Khan. His Y chromosome would obviously have had ancestors, and our best estimate of the TMRCA of starcluster chromosomes lies several generations before his birth.*". ¶ But it was Genghis himself (and descendants) that conquered and occupied his empire, not his ancestors. – Ray Butterworth Aug 30 '22 at 15:02
  • @RayButterworth, it was Genghis Khan *and* his armies that conquered his empire. These armies would most likely include many men carrying the same Y chromosome (four brothers to begin with), although these likely didn't have as many wives and concubines as Genghis Khan himself. – Jacinto Aug 31 '22 at 07:58