Gene Expression

Why Asians are so short (perhaps)

A few days ago I posted on a gene, HMGA2, which seems to be implicated in a small proportion of the normal human variation in height. There seems to be an SNP which comes in two flavors which results in a different in height in an additive & independent manner. A friend of mine pointed out that this SNP exhibits different frequencies in different populations. The “short” allele, which tends to have an average effect of decreasing the expectation in height, is the derived form. That is, it is a newer mutant in relation to the ancestral “tall” allele. Second, it seems that it is extant at a much higher frequency in East Asians than amongst Europeans and Africans. I won’t repeat the evolutionary speculations I offered in my previous post, but it seems clear that small chunks of data such as this will be fertile seed for future conjecture and model building.

Comments

  1. #1 agnostic
    September 6, 2007

    Maybe shorter people are more able to keep their balance on horses, the better to decimate a sedentary population and make off with their women.

  2. #2 CRM-114
    September 6, 2007

    Three centuries ago, the Scots were short people. Now they’re tall. It’s got to be the diet.

    I live in Alhambra, California, which has a sizeable community of Chinese descent. The oldsters tend to be short, the kids not. It’s got to be the diet.

  3. #3 razib
    September 6, 2007

    I live in Alhambra, California, which has a sizeable community of Chinese descent. The oldsters tend to be short, the kids not. It’s got to be the diet

    are they as tall as whites and blacks? is that the diet?

  4. #4 Jason Malloy
    September 6, 2007

    Adopted Koreans (and other Asian groups) do not grow as tall (or fat) as their white siblings. Perhaps they were ‘undernourished’ in the womb or some such, but then why do they do better at school, etc?

  5. #5 cuchulkhan
    September 6, 2007

    Lactose intolerance too.

  6. #6 razib
    September 6, 2007

    Lactose intolerance too.

    the traits aren’t analogous though. LI is a single locus mendelian trait. height is a quantitative trait with no locus of large effect an a large fraction of potential environmental variance. the adoption studies are the clinchers though; some argue that diff. east asian diet is the reason behind the shorter heights of modern japanese, but obviously not as much of an issue with korean adoptees.

  7. #7 agnostic
    September 6, 2007

    Plus, why do Af-Ams, who are also more likely than Whites to be LI, grow taller than Whites or Asians? And Asians are more likely to eat healthier food, and Af-Ams more likely to eat junk.

  8. #8 razib
    September 6, 2007

    Plus, why do Af-Ams, who are also more likely than Whites to be LI, grow taller than Whites or Asians?

    last i checked the growth charts they were about the same height as american whites.

  9. #9 hip hip array
    September 6, 2007

    height is a quantitative trait with no locus of large effect

    Mbuti what about the pygmies?

  10. #10 razib
    September 6, 2007

    Mbuti what about the pygmies?

    same. they aren’t like dwarves from what i know. probably lots of loci of small effect.

  11. #11 James
    September 6, 2007

    I grew up in a Chinese/Vietnamese enclave in the bay area, so about half the kids I grew up with were Asian like me. I’d say diet is the biggest factor. My diet was equal parts cheeseburgers and pho, and I ended up six feet tall, 4″ taller than my dad, and both of my sisters are 5″ taller than mom, who is a wee 4’11″. But Asian guys taller than 6’2″ are very rare, probably as unlikely as a white guy over 6’5″.

    Lactose intolerance doesn’t seem to be a huge issue. In elementary school all the kids drank their chocolate milk every day, and in college, like 3/4 of my asian friends drank milk without a problem. The asian glow was much more prevalent. I’m 21 and it was only two years ago that dairy started giving me the runs.

  12. #12 razib
    September 6, 2007

    re: LP, the bigger issue that people don’t get full nutritive value (about 1/3) cuz of no lactase.

  13. #13 Lixing
    November 10, 2007

    Its probably a mixture of genes and diet. I’m from a relatively prosperous asian nation whose traditional fare are really tasty, but usually only made up of carbo and fats. I’m 19 this year, 5’11, and thats pretty much average amongst the younger crowd. Most of the older generation asians(that lived through hard times) are shorter, averaging about 5’7, with the world war 2 generation at about 5’4.

    However i must hightlight that, while the average height of teenagers here may be close to average american height, the number of kids who hit 6’5 or more are like one in every hundred.

  14. #14 tom bri
    November 11, 2007

    I lived about 15 years in Japan. In public I always towered over men of my generation, but the high school kids looked me in the eye.

    One funny thing, it seemed to me that the girls, that is late teens and 20s, had gained more height than the young boys. There seemed to be lots of really tall girls around.

    The traditional Japanese diet is severely deficient in certain nutrients, but the younger generation is growing up on Macs. Don’t know how tall they will end up, but lots taller than previous generations.

  15. #15 kp
    September 3, 2009

    do calcium intake has any effect on height? I mean, are Americans taller because they consume more calcium than Asians do? I’m so curious about this
    thanks

  16. #16 sg
    November 19, 2009

    The Asian diet, if it contains seafood, tofu and vegetables is actually richer and healthier than the typical North American Diet. Seaweed, tofu are actually excellent sources of protein and minerals. The main reason why people think protein ie: hamburgers is making them bigger and taller is : growth hormone. Hormones found in beef and chicken is making a whole generation of men/women grow faster and bigger.Also, hormones are found in dairy products also ( cheese, milk).So, my guess is DIET but it’s the growth hormone not the protein, necessarily.