April 14, 2008

Ashkenazi Jewish Genes in 3-d

In response to readers' questions about how Ashkenazi Jewish genes compare to other groups', Utah anthropologist Henry Harpending sends along a 3d graph he and Greg Cochran created for (but didn't use in) their famous paper on the evolution of high IQs among Ashkenazi Jews.

You can click on the graph to see it in a larger, more readable version. The main left to right axis is the first Principal Component, accounting for 45% of the variance. The axis running from the middle bottom to the upper right is the second Principal Component, accounting for 25%, while the vertical axis is the third PC, accounting for 15%.

As always, the principal components methodology doesn't tell you what the axes mean. That's just how the data cluster and you've got to come up with insights to figure out why. (Don't look to me for them.)

On the first two axes, Ashkenazi Jews are rather close to "Europeans" and "Russians." They are similar to Yemenites (from Southern Arabian peninsula) on the first axis, but not on the second. And they are similar to Samaritans (who currently subsist on two hilltops in Israel), good, bad or indifferent, on the second axis but not on the first. They are fairly similar to the Druze (of Lebanon and Israel) on the first two axes, but not on the third.

On the other hand, if you included some Australian Aborigines, Bushmen and Tierra del Fuegans on this graph, probably all six of these data points would look clustered fairly closely together.

So, Ashkenazis look pretty European on this chart compared to a few Middle Eastern groups. But, as the recent graph showed, genetics has progressed to the point where Ashkenazis (at least those with four Ashkenazi grandparents) can now be reliably distinguished from other Europeans.

Tautologically enough, when it comes to ancestry, everything is relative.

My published articles are archived at iSteve.com -- Steve Sailer


TGGP said...

GNXP has a post showing Ashkenazi to be closer to northern Levantines and Anatolians than southern Levantines here.

Anonymous said...

Is this the famous analysis done with a hundred or so "neutral" SNPs grabbed from ALFRED?

Anonymous said...

Keep in mind that this doesn't really apply to political alliances (and hence doesn't really rebut the white nationalist argument about Jews not being whites). Jews and blacks don't have a lot of genes in common but vote together in American elections. The 'I and my brother against my cousin' thing doesn't work when you have only two parties.

Heck, France is next door to England, and look how they get on.

Anonymous said...

I am reading in Text Size "largest", in which you apparently refer to a Saint Henry Harpending. Just thought you might like to know.

Anonymous said...

The Samaritans aren't in Israel proper, but near Nablus in the West Bank.

Anonymous said...

What's new? The Jews are a unique genetic population, but, in the grand scheme of things, not all that different from Europeans, especially Italians. Isn't that what everyone can see for themselves?

Anonymous said...

Isn't it *principal* component, not *principle*?

No need to post this comment.

Anonymous said...

Thanks for posting this graph, which proves the point I made in the comment to the last post, a comment that a bunch of people disagreed with.

My point before was that Ashkenazi Jews are very close to other Europeans and not to people from the Middle East, and this new chart confirms that pretty well.

Anonymous said...

Very interesting. I would have suspected the Ashkenazim to lie further apart from Europeans, more intermediate between Mideasterners and Europeans.

For comparative purposes, it would be interesting to divide up the category of "Europeans" and see far apart the Germans, Irish, Spanish, Greeks and/or Sardinians are in relation to the groups already listed using this methodology.

Anonymous said...

"Nablus" is the city referred to in the Bible as Shechem, capital of the Kingdom of Israel. However, the Bible makes no mention of the "West Bank."

About half of the Samaritan community resides in the Israeli city of Holon.

Anonymous said...

I am a blue eyed Ashkenazi Jew who looks 100% European. I have no dark middle eastern looking features. Nobody would have any idea I was Jewish unless I would tell them. Yet all four of my grandparents are Jewish, they all immigrated from Kiev around 1900.

My relatives all have light eyes and skin. Does this mean there is non-Jewish European in my genes? My Grandparents never mentioned any gentiles in our family tree. Maybe it happened before their time?

Anonymous said...

I am a blue eyed Ashkenazi Jew who looks 100% European...Does this mean there is non-Jewish European in my genes?

Obviously, yes! Either that, or a whole lot of your ancestors had the most astonishing number of improbable spontaneous mutations.

It's not complicated. Probably almost no ancient Mid Easterners had blue eyes. Almost all the blue eye genes in the world are among Northern Europeans, which is where the mutation almost certainly originally appeared. Since blue eyes are recessive, if you're blue-eyed, you must have a complete pair of those genes, so it's pretty likely that a large fraction of your ancestry is actually Northern European rather than Judean.

In fact, if we (very crudely) assume that blue eyes are a neutral-marker trait, we can (very roughly) estimate the fraction of Ashk Jewish ancestry that is actually Northern European. Surprise, surprise!---we basically get the same answer as all those highly-complex modern multiple SNP studies using fancy laboratories and computer algorithms.

Anonymous said...

And what makes rku think blue eyes are a neutral trait?

Anonymous said...

And what makes rku think blue eyes are a neutral trait?

Well, I'm not aware of anything useful that blue eyes "do". Maybe they provide telepathy, and the scientists are all covering it up.

Anyway, suppose blue eyes did provide something extremely useful, with a 5% advantage, which is very large in evolutionary terms. Since they're recessive, you'd need a very high rate of blue eye genes to even start seeing that advantage. Presumably, Jews acquired up their blue eye genes when they started living among heavily blue-eyed people in the last 40-odd generations. So that 5% advantage wouldn't have had much time to have any huge impact on the distribution.

Here's another example. American blacks are something like 15-20% white by ancestry, but blue eyes are extraordinarily rare. So the Northern European portion of Jewish ancestry must be enormously higher than that since a far number of Jews have blue eyes.

Remember, I'm talking about an "extremely crude" ancestry estimate with these examples.

Unknown said...

It would be interesting to repeat the analysis using only SNPs which are thought to be related to mental processing.

Get the principal vectors which best describe the European populations and then evaluate them for world-wide populations.

A closely related analysis would be to get the vectors for the same SNPs which describe the world-wide populations.

The first plot would tell us how non-European populations differ from European populations in the directions which describe European brain functioning.

The second plot might be harder to interpret, but if it looked the same it would suggest that different processing was a matter of degree and not kind.

Maybe interesting also to analyze males and females separately ... but perhaps that is under hormonal control.

Anonymous said...

Is rku retarded or just extremely unimaginative?

I can think of at least four ways blue eyes may have been selected for in AJ.

1) sexual selection
2) other direct selection for a European-like appearance (e.g. Jews who look more like Europeans are more likely to survive pogroms, more likely to be trusted in business dealings with Europeans and therefore able to grow wealthier and support more offspring, etc.)
3) selection for fair skin (with which blue eyes are linked) through the action of disease and/or the two factors above
4) selection for deliberative, "self-paced" (with which blue eyes are associated) as opposed to "reactive" personality traits

In fact, if we (very crudely) assume that blue eyes are a neutral-marker trait, we can (very roughly) estimate the fraction of Ashk Jewish ancestry that is actually Northern European. Surprise, surprise!---we basically get the same answer as all those highly-complex modern multiple SNP studies using fancy laboratories and computer algorithms.

What the hell are you talking about? Which "highly-complex modern multiple SNP studies" have estimated the fraction of Northern European genes in AJs?

Anonymous said...

I take issue with the idea that Jews somehow evolved high IQ recently, like say in the last 5 millenia.

The Jewish religion is extremely complicated and could only be constructed by people who were already highly intelligent. Much more so than the average.

It's more realistic I think to assume that "Jews" have existed as a race for many many centuries before anyone had ever heard of Moses. They were probably just called something else.

Race determines culture, not the other way around.

Anonymous said...

I can think of at least four ways

Aren't they supposed to be a crude paternity test, too?

Anonymous said...


Is rku retarded or just extremely unimaginative?

Well, if those are my choices, then I hope it's the latter!

Look, if we're talking the blue eyes *trait*, you'll only get selection on the double recessives. So you'd need to START with 10% blue-eyed genes just to get selection on 1% of the population. That's obviously not enough to get any rapid change in overall gene frequency.

Since most---but not all---Northern Europeans are blue-eyed, you'd probably need at least 30+% NE admixture BEFORE you can get enough actual blue-eyed Jews to get significant selection. And I'm really, really skeptical that the blue-eye trait has anything like a 5% advantage, which is HUGE in evolutionary terms.

As for blue-eyes being *linked* to something else that actually *is* useful, sure that's perfectly possible, but pretty speculative. I'm not aware of anything worth 5%, but science always does move forward.

If there's some obvious flaw in my logic or my arithmetic, please correct me.

And I'm certainly no expert on Jewish ancestry issues, but I do remember that around the time the landmark Cochrane-Harpending paper came out, I saw some estimate that Ashk Jews were somewhat over half Mid Eastern and somewhat under half Northern European, which seemed pretty plausible to me. For all I know, maybe that's now been superseded by some better study.

Anonymous said...

Yes, svigor, something like that has been proposed. Personally, I don't recall finding the argument particularly compelling. Maybe I'll look into it again.

Blue-eyes are also said to be more acute under certain (humid, low-light) conditions.

Anonymous said...

A Jew with blond hair and blue eyes who looks Jewish...Brett Marx, born December 26, 1964 in Los Angeles, California, is a movie and television actor (The Bad News Bears). He is the grandson of Milton "Gummo" Marx and great-nephew of Harpo, Chico, Groucho and Zeppo Marx.

Anonymous said...


It sounds like the estimate you're thinking of is the much-touted but never-published one by Cochran and Harpending.

I have never seen an admixture estimate using high-resolution SNP data.

Anonymous said...

According to Michael Hart's book, there was a high degree of intermarriage among Jews and nonJewish populations in Roman times. Also, in the dark ages, there was extensive proselytation by Jews and intermarriage with local nobles. See Bachrach's book; Jewish Policy in Middle Ages, or something like that.