The Kalash in perspective

By Razib Khan | February 15, 2012 10:52 pm

 

When Zack ran ChromoPainter/fineStructure on South Asians the results naturally yielded a blueish hue along the diagonal. This is expected because the diagonal represents the population’s own relationship with itself. The bluer the diagonal, the more inbred and isolated the population is likely to be. To the top left you see various Austro-Asiatic tribes, in the middle the “Gujarati A” population from the HapMap (probably Patels), and in the bottom right various Pakistani groups, who presumably have higher rates of consanguinity than the South Asian norm. But one group stands out among the other Pakistani groups: the Kalash. They’re highly endogamous because they’re the last pagan population in Pakistan, isolated in the fastness of the Chitral. It is likely that if their region of Pakistan had been under Afghan, and not British, rule these people would have been forcibly submitted to Islam like their Nuristani cousins across the border 100 years ago. As it is I assume that at some point I may have to update these posts with the note that Pakistani Taliban forcibly converted the few thousand remaining Kalash to Islam. Such is the march of history in the abode of peace.

Religion may be a critical explanation for this isolation, because the similarly isolated Burusho of northern Pakistan are not nearly as inbred. Though the Burusho are speakers of a linguistic isolate, they adopted Islam ~500 years ago, and so are likely to have intermarried more frequently with outsiders. The Kalash isolation means that in some ways they’re relatively useless in comparative genomic analysis. Though they are not an ‘ancestral population’ they routinely jump out as distinctive early on in PCA or ADMIXTURE/Structure/frappe analyses. In short, they are close to one large extended family. Nevertheless, they can be somewhat informative when these particularities are taken into account.

Presumably the Kalash are distant from other populations because of their isolation, but their relationship to other world populations will retain the same general conformation before their endogamous period. With that in mind I ran a narrow South Asian focused ADMIXTURE run. With ~400,000 markers I had: The Kalash, Burusho, Brahui, Pathan, Gujarati Patels, Hazara, Uygur, Russians, Japanese, Bantus of Kenya, Basque, Adygei, and Druze. Below are the results for K = 7 for selection:

 

Here are the Fst (genetic distances) between the various modal elements (labelled for convenience):


Brahui Bantu Russian Japanese Gujarati Druze Kalash
Brahui 0 0.179 0.062 0.135 0.062 0.075 0.073
Bantu 0.179 0 0.19 0.219 0.168 0.188 0.202
Russian 0.062 0.19 0 0.145 0.068 0.062 0.084
Japanese 0.135 0.219 0.145 0 0.099 0.158 0.146
Gujarati 0.062 0.168 0.068 0.099 0 0.078 0.07
Druze 0.075 0.188 0.062 0.158 0.078 0 0.096
Kalash 0.073 0.202 0.084 0.146 0.07 0.096 0

And some MDS’s to illustrate:

Because of their light skin and hair both the Kalash and Burusho have inspired claims that they are “lost white tribes.” This is almost certainly false for the Burusho. Aside from their moderate East Asian admixture, they’re not so different from other Pakistanis in their region genetically. The older uniparental results confirm this; the Burusho have many characteristic South Asian mtDNA lineages. The Kalash mtDNA is almost totally West Eurasian, but looking at the “Kalash” component above you don’t  see particular closeness to the Russian/European modal component in comparison to the South Asian ones. Yet looking through the images at the links above I think you’ll be struck by how European some of the Kalash and Burusho seem in visible appearance, as well as how similar to each other they look (though the Burusho do sometimes show evidence of East Asian admixture, as you’d expect). This may simply be an artifact of Western photographers who are struck by the fact that “indigenous people” are capable of staring back at them with blue eyes, but it may also be local adaptation. The Kalash and Burusho almost certainly arise from the fringes of the ancient admixture between West Eurasians and South Eurasians, but their phenotype exhibits far less of the South Eurasian imprint than the lowland peoples of the Punjab. I have no good model for why mountains would foster such a phenotypic difference, but that’s all I’m left with.

In the end the Kalash and the Burusho are the best refutation of the “blondes going extinct meme.” The meme posits that the European physical characteristics par excellence are becoming submerged in a rising tide of color. The racial panic was explicit during the Victorian era, but more recently it has been sublimated and left inchoate because of the reigning ideology of multiculturalism whereby “right thinking” whites wouldn’t dare express racial consciousness (despite clear revealed preferences). But the Kalash and the Burusho illustrate that even out of a period of admixture distinctive traits from one parental population can reassert themselves through stochastic (e.g., drift) or deterministic (e.g., selection) forces.

CATEGORIZED UNDER: Anthroplogy, Human Genetics
  • Charles Nydorf

    Please explain how to read a heat map.

  • http://www.huxley.net/bnw/index.html Mustapha Mond

    “right thinking” whites wouldn’t dare express racial consciousness

    Indeed, you yourself seek to ban us from this blog.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    #2, right, just banned you. #1, i did explain it succinctly. follow zack’s post, or read my post on the new technique. with all due respect, do a little of your own legwork sometimes.

  • Vitasta

    Weiss, KM and Long, JC in Non-Darwinian estimation: My ancestors, my genes’ ancestors generate a heat map using, “…the average of Nei’s unbiased gene identity statistic over 678 loci within each individual, and between all pairs of individuals (Nei 1987)” with Noah Rosenberg’s data. They point to a rather surprising result from this re the Kalash, “Fifth, there is high gene identity within and between Kalash individuals but in comparison to people in different geographic regions the Kalash present a pattern that is similar to Europeans and South Asians. This result is somewhat surprising because the structure program output depicts the Kalash as a unique ancestral population.” Quite interesting and not dissimilar to the results with fineStructure, I thought.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    also, my banning of #2 had to do with douchebaggery. no more discussion of that.

  • Ibra

    “The bluer the diagonal, the more inbred and isolated the population is likely to be”

    Just for fun you should run this with the Onge :D

  • Liesel

    The link to the Kalash and Burusho images both go to the Kalash images. I think you meant this http://www.bing.com/images/search?q=burusho&view=detail&id=1DB1A0A6475DBE156088CA557ABCEF2D32080514&first=0&qpvt=burusho&FORM=IDFRIR for the Burusho.

    “would foster such a phenotypic difference, but that’s all I’m left with.”

    I wonder what their actual phenotype in person would look like. If someone brought in a Northern European and placed them to the right of a Kalash and placed a Pashtun to the left them in the same photograph we might see a noticalbe difference. I realize eyewitnessness describe the Kalash as lighter than their neighbors so it is not all smoke and mirrors. However, lighting and camera angle could still be accentuating this creatung the rather romantic fantasy of “lost white tribe.”

  • Karl Zimmerman

    Someone feel free to correct me, but from what I’ve seen, at least some Pashtun are on the lighter side as well, if not as light as the two populations discussed above. Certainly they seem to have a relatively high incidence of light eyes, although as adults dark brown to black hair seems to be the norm. Although South Asian-looking features are predominant, I know I’ve met Pashtuns who wouldn’t look out of place in Europe anywhere except Scandinavia.

    Here’s an extreme example (from Chitral) I found on the web. It’s associated with an interesting thread on a Pashtun discussion forum where Pashtuns are discussing the commonly held variations in appearance among the different Pashtun tribes. It’s obviously all hearsay (although better than the average non-academic discussion forum), but from what I can gather, it’s the populations closest geographically to the Kalash and Burusho which show the most “European” features – suggesting they’re mainly descended from highland groups which assimilated into Pashtun culture later.

  • Charles Nydorf

    Now I see. The colors run from blue through red to yellow with blue indicating the most intense coancestry.

  • Grey

    Completely tangential but some of this made me wonder about Dionysian rituals.

    http://www.indigenouspeople.net/Kalashvalley.htm

  • tocharian

    I think they are remnants of the Tocharians. Probably the proto -Caucasoids occupied the steppes from China to western europe in small hunter gatherer bands. At some point the tocharians in Pakistan were pushed up to the mountains by proto – dravidians from the south.

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    #11, i don’t give a shit what you think. why? uyghur and kalash are both in HGDP and haven’t see anything which relates them. though perhaps uniparental?

  • ackbark

    Is it that their more western appearance is an effect of local standards of beauty that are contra the surrounding larger population, a subtle, unconscious way of preserving their specialness?

    (I think I said something like that before in another case.)

  • http://blogs.discovermagazine.com/gnxp Razib Khan

    Is it that their more western appearance is an effect of local standards of beauty that are contra the surrounding larger population, a subtle, unconscious way of preserving their specialness?

    from what i know about pakistan, probably not (as noted many pathans look like the kalash). and some kalash look like more conventional south asians (albeit, of the northwest variety).

  • AV

    “I have no good model for why mountains would foster such a phenotypic difference, but that’s all I’m left with.”

    Couldn’t their (the various Northern Pakistani tribes) phenotypic variation easily be explained by two rather important factors as follows?;

    Weather and Climate – Climatic conditions and altitude might also well be the reason behind the occurrence of such individuals. The Hunza Valley, home to the frequently light pigmented Burusho, is mountainous in nature. North Waziristan, in the Federally Administered Tribal Areas is known to have a hilly geographic character. Chitral, home to the Kalash tribes is also rather mountainous and filled with passes. In the winter the night time temperature occasionally drops to -10 C with snowfall being abundant.

    Endogamy – The highly tribal mentality of these people could also be one of the factors contributing towards the occurrence of such traits. As many have noted, these features are often seen in close-knit tribes in isolated geographic areas. The Kalash are the best example, but so are some of the mountain Pashtun clans. The light traits among them occurring so frequently might simply be a by-product of their inbreeding. Thus, the lack of out-breeding, has successfully spread these traits in a few generations in specific clans and tribes rather fast. Indeed, even their genetics throws light on their distinctiveness relative to others. The Kalash have for instance, through generations of inter-marriage, formed their own genetic cluster as increased isolation will only increase the rate of homozygosity. Thus, their divergence from other Eurasians has been accelerated through their natural isolation. To add to this, their cultural distinctiveness relative to sorrounding populations only further reinforces the same. This is why they always cluster within themselves and show minimal admixture from outside. This has been shown in a number of experiments, and attempts at extrapolating their genome structure have been unsatisfactory due to this.

    Although one can’t help but wonder whether the occurrence of such phenotypes might be attributed to the ~15% Northern European admixture that groups like the Burusho and Pathans exhibit in ADMIXTURE, although morphology-specific phenotype genetics seems to be a rather ambiguous science as of now, and these features occur among West-Asians as well..

NEW ON DISCOVER
OPEN
CITIZEN SCIENCE
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

Gene Expression

This blog is about evolution, genetics, genomics and their interstices. Please beware that comments are aggressively moderated. Uncivil or churlish comments will likely get you banned immediately, so make any contribution count!

About Razib Khan

I have degrees in biology and biochemistry, a passion for genetics, history, and philosophy, and shrimp is my favorite food. In relation to nationality I'm a American Northwesterner, in politics I'm a reactionary, and as for religion I have none (I'm an atheist). If you want to know more, see the links at http://www.razib.com

ADVERTISEMENT

See More

ADVERTISEMENT

RSS Razib’s Pinboard

Edifying books

Collapse bottom bar
+

Login to your Account

X
E-mail address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it e-mailed to you.

Not Registered Yet?

Register now for FREE. Registration only takes a few minutes to complete. Register now »