Natural selection for height in Europeans

By Razib Khan | May 14, 2011 8:26 pm

It is known that Northern Europeans tend to be somewhat taller than Southern Europeans. This seems intuitively obvious if you spend a bit of time around representative populations. Growing up in the Pacific Northwest I’ve always been on the short side at 5 feet 8 inches, but when I was in Italy for 3 weeks one year back (between Milan and Rome, with disproportionate time spent in the Piedmont) I didn’t feel as small (I recall feeling similarly when I was in Cajun country in the early 2000s). Steve Hsu alerts me to the fact that Luke Jostins is back blogging at Genetic Inference, reporting from the Biology of Genomes meeting. Apparently Michael Turchin has found that:

1) Alleles known to be associated with greater height are found at higher frequencies in Northern Europeans

2) Alleles known to be associated with greater height also exhibit signatures of natural selection


He used the GIANT consortium data set. How big is it? 129 thousand individuals! Luke adds:

This is a textbook example of how an evolutionary study should be done; you show a phenotypic difference exists, that it is heritable, and that it is under selection. This opens the question as to why height has been selected in Northern Europe (or shortness in Southern Europe). Could the same data be used to test specific hypotheses there?

One thing we do know is that there isn’t much difference in heights between black Americans and white Americans, who are predominantly Northern European in ancestry. I wonder if perhaps the smaller sizes of Southern Europeans is due to the fact that these populations have lived for a longer period under a high density agricultural regime than either Northern Europeans or Africans (northern Sweden still was dominated by hunter-gatherers until ~5,000 years B.P.). My working hypothesis that for various reasons stable agricultural societies may reduce lifetime mortality rates but maintain higher levels of morbidity, making large body sizes less feasible. But that’s just speculation. At last European is a good testing ground for these sorts of explorations, as obviously obligate nutritional differences aren’t much of an issue anymore on that continent.

CATEGORIZED UNDER: Anthroplogy, Genetics, Genomics
  • Eric

    129,000 thousand individuals? That’s a lot! You emphasized it, so I can’t be sure this is wrong, though. Is it 129,000 or 129,000,000?

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

    well now, i got a little carried away with that typo! :-)

  • Robert

    What I find puzzling is why the average height of Europeans is still increasing. I should think that infant malnutrition had been eliminated by 1960.

    http://dienekes.blogspot.com/2007/03/evolution-of-adult-height-in-europe.html

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

    right. and white americans have been stagnant. lots of confusion here.

  • Justin Giancola

    If you look up the average height of African nations they are not tall, in the way we tend to think of African-Americans here. Everything I’ve seen averages no taller than 5’7. Even watching things on tv, like travel programs they don’t seem tall, esp. combared to whites. Blacks in the US are probably tall due to admixture with whites or through possibly selection during slavery???

    Like someone posted a while ago on here about some Nilotic group in Chad or Sudan that are supposedly tall and showed it was very dubious, I think African height could well be a myth.
    The trope of the giant African guy in movies.

  • simplicio

    Eyeballing the chart posted by #3, it rather looks like S. Europeans are increasing their heights faster then their N. European peers. As the southerners are shorter, it kinda suggests the heights are converging, and hence, determined by something other then genetics.

    Is it certain that the genes mentioned are really correlated with height? It seems not impossible they’re just correlated with N. Europeans, who are taller for whatever non-related reason.

  • harryp

    there must be a reason for everything, but as far as I know all the genes they’ve found so far, still account for about 8-10% of te variance of height. So why should natural selection account for these differences and not, say ‘food selection’ f.e.?

  • bucephalus

    “white americans have been stagnant. lots of confusion here”

    I assume you mean stagnant in growth of height. Northern Europeans keep getting taller whereas white Americans do not. This could be because white Americans have a large Mediterranean component and a bigger admixed population? Another possibility is income inequality : Northern European incomes are more evenly distributed. I would say “definitely” rather than possibly except that I don’t know about the white-only income inequality in the USA. I’m sure income/wealth distribution for white Americans is more skewed than in northern Europe, but not as skewed as the all-American income/wealth distribution.

  • dave chamberlin

    @5 African height is not a myth, there is more genetic diversity in Africa so we have pygmies and we have at least one tribe where 5% of the males are over 6 feet 8 inches tall. Height is inherited but it also adjusts environmentally over generations. I have no clue how this works , but there is irrefutable evidence that people get taller or shorter for generations when there is a large variation in the protein of the diet of growing children. It is probably worth mentioning that increased genetic height has been found in the same locations as the lactose tolerance into adulthood mutation is found, both in northern Europe and among the cattle herders in Africa. This makes sense when you consider lactose tolerance as a positive feedback mechanism to greater height in a general population which before the industrial revolution was always being pushed to it’s malthusian limit.

  • Luke

    @simplicio

    These variants have been validated in family-based cohorts (which grants a perfect population stratification control), so we know that they are height variants per se.

  • http://forwhattheywereweare.blogspot.com/ Maju

    Basques are on average higher than Brits (but not Irish maybe) and Galicians, once a short population, are now taller than Basques. Swedes and some Germans of the robust Merkel/Shroeder variant may be really tall but that’s about it.

    Spaniards in general have grown maybe up to 10 cm in some cases (old people are almost invariably short, very short, young people are not: they tend to be tall).

    Anyhow things vary a lot depending on populations: Italy is not representative of anything but Italy and even some parts of Italy surely do not represent at all other parts of Italy (notably the South-North duality but there’s more than that).

    What about Serbs? I’ve been in Serbia and I think Serbs are quite tall on average, probably more than their northern neighbors, the Hungarians.

    I’d say that abundance of meat and specially milk in food also matters. Milk may be a key because some southern Europeans (Greeks more than Italians, these more than Iberians, these more than Basques, which ingest a lot of milk and dairies and are traditionally tall) tend to be lactose intolerant and therefore do not eat much milk (cheese maybe but it’s an expensive product).

  • Pingback: Selección natural en la altura de los europeos | Mundo 3.0

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

    If you look up the average height of African nations they are not tall, in the way we tend to think of African-Americans here. Everything I’ve seen averages no taller than 5’7

    you need to look at west african nations. looking at a whole continent as indicative is kind of dumb, isn’t it (being frank)? the point about admixture is interesting and i wondered. if you had CDC state level data (i’ve only seen national) it would be interesting to check how it varied state by state. we know that there’s more admixture in northern and western states than in the southeast.

    p.s also, nutrition and life circumstances can vary quite a bit within africa.

  • http://washparkprophet.blogspot.com ohwilleke

    Isn’t it equally possible that the alleles are simply ancestry informative?

    At the population level height is a great indicator of affluence and proper nutrition. For example, the Koreans and Japanese are much taller than they were a couple of generations ago, and the Dutch experienced a major historical height boost. Greater height could be a proxy for greater affluence in Northern Europe relative to Southern Europe. The alleles, in turn, could be a proxy for anything that differs systemically and selectively from North to South, since any allele that capture a North-South ancestry axis will, as a result of differing levels of affluence, coincidentally also capture of difference in a health phenotype.

    To the extent that it also shows intra-population height differences, it could be a class rather than a height linked allele. For example, a gene for conscientiousness, which would have socio-economic implications, if it also had a North-South cline, would probably show both intrapopulation and interpopulation height affects at a statistically significant level due to it being a proxy for ancestry and social class that lead to nutritional differences that lead to height differences.

  • http://washparkprophet.blogspot.com ohwilleke

    “Milk may be a key because some southern Europeans (Greeks more than Italians, these more than Iberians, these more than Basques, which ingest a lot of milk and dairies and are traditionally tall) tend to be lactose intolerant and therefore do not eat much milk (cheese maybe but it’s an expensive product).”

    A very plausible hypothesis.

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

    Isn’t it equally possible that the alleles are simply ancestry informative?

    please check luke’s original post if mine wasn’t clear enough.

    1) these are alleles already discovered in previous GWAS as being related to height. they’re not random alleles.

    2) they seem to exhibit signatures of natural selection.

    that doesn’t mean that this is a finding that will hold up. all of the individual points exhibit uncertainty (e.g., tests for natural selection have false positive rates just as GWAS do), but their joint probability is suggestive. but there are a few extra points to consider before assuming that this is population stratification.

  • Robert

    “A very plausible hypothesis.”

    Except it doesn’t account for the current growth spurt in height for Spanish and Italian populations.

  • dave chamberlin

    Razib is da man when it comes to genetics. Is there any explanation how human height is both passed on genetically and increases by generations of well fed people or decreases by generations of malnourished people. I can’t wrap my mind around how this can happen, but it does. Do you know why?

  • Robert

    “Is there any explanation how human height is both passed on genetically and increases by generations of well fed people or decreases by generations of malnourished people.”

    One can certainly conceive of positive feedback loops for Scandinavians. Taller folks would be stronger and more efficient at plowing stony fields and manhandling fishing nets (or occasionally battle axes) in the calcium and protein rich environment of cattle farming around the North Sea. At the margin they could occasionally afford to support larger families so over a couple of hundred generations there would be selection for height. Conversely in an environment with less plentiful and reliable food supplies larger size would be a liability as extra tallness could not be put to use in larger harvests and would require more caloric intake to maintain larger individuals.

    However none of this theory would explain why contemporary Italians are getting taller.

  • Justin Giancola

    @Razib, but I looked at nations from the whole continent, including west africa. Granted these are sources one finds through a quick internet search but can someone show me a source saying something radically different? No Dinka stuff please, which is what I was referring to earlier.

    quick compare:
    Ghana 169.46 cm (5′ 6.7″)
    Nigeria 163.8 cm (5′ 4.5″)
    Côte d’Ivoire 170.1 cm (5′ 7″)
    Gambia 168.0 cm (5′ 6.1″)
    Cameroon 170.6 cm (5′ 7.2″)

    Côte d’Ivoire 5’7.8″
    Gambia 5’7.7″
    Cameroon 5’7.6″
    Ghana 5’7.5″
    Nigeria 5’5.7″

    Mali 5’8.7″

    http://forums.interbasket.net/f10/average-male-height-by-country-updated-9287/
    http://wiki.answers.com/Q/What_is_the_average_height_of_men_and_women_worldwide
    http://en.wikipedia.org/wiki/Human_height

    “Is there any explanation how human height is both passed on genetically and increases by generations of well fed people or decreases by generations of malnourished people.”

    This is the whole idea behind epigenetics.

  • http://www.pazzanibrindes.com.br brindes

    Interesting. Somehow I always tought about the taller populations being associated with 3 things:

    1. Natural selection, in the case of the africans who were slaved and under such poor living for some generations the fittest (stronger/tallest) were able to carry on with their genes

    2. Food income. People that have a more abundance in their childhood tend to be taller.

    3. Lactose Tolerance. I’ve met a few swedens and germans in my life and they were the tallest person i’ve ever met, I also read that those are some of the few human lineages that are able to full digest the lactoses. So it wasn’t hard to made that assiumption.

    However those being associated with a specific part of the gene is new to me. I wonder what would be the benefit of being larger? It makes human more ineficient in energy spending, and since a big or small human wouldn’t make a big difference in surviving or not (since our survival is more relate to our intelligente than anything else) i just can’t see a good evolutional reason to being taller.

  • Onur

    Spaniards in general have grown maybe up to 10 cm in some cases (old people are almost invariably short, very short, young people are not: they tend to be tall).

    There is a similar trend of increase in height in Turks: young people tend to be taller than both of their parents. 1.80 m (5.9 ft) or more height is much more common in the young generation than in previous generations (I am 1.80 m tall and I see many people of similar or more height in the young generation).

  • Justin Giancola

    “Is there any explanation how human height is both passed on genetically and increases by generations of well fed people or decreases by generations of malnourished people.”

    This is the whole idea behind epigenetics.

  • Onur

    since our survival is more relate to our intelligente than anything else) i just can’t see a good evolutional reason to being taller

    I think this is not so true for the barbaric ages of Northern Europe, when male competition (not necessarily for females, but that was surely one of the most important factors in male competition :) , even if indirectly) of Northern Europeans was much more deadly and height/robustness related (with many battles of very little equipment and also with many hand to hand fights) than today.

  • Brian

    So,… from the article and the comments I would say that this looks less like evolutionary “natural selection”. It is factual that diet, environment and activity account for most changes in human appearance (or any other species). Change the combination of any of those three factors and you can force physical and mental alterations in species. That is the obvious “duh” in this.

    Creating a dog breed is the same. You change it’s diet, its environment and its activity. After a few generations of breeding with similar dogs, you get a new breed. However, you don’t get a new species. It’s still a dog. Put the breed back in its original environment, diet and activity and it will go back to what it was after several generations.

    What you have in this study are some people taller than others, but in the end, you still have HUMANS. It’s not like we are witnessing the birth of a new species.

  • dave chamberlin

    Thanks Justin and Robert for attempting to answer my question, I think I need to rephrase it to make my point. How can my children be inches taller than they would otherwise be with identical genes and environment simply because generations that immediately preceded them were better fed. What I am referring to is transgenerational epigentics, wikipedia has a brief description, but it isn’t very helpful.

  • http://bioinfoblog.it Giovanni Dall’Olio

    1. Adaptation to the climate: smaller stature means lower skin surface, so less sweating in a warm climate. I don’t know if it is really true that tall people suffer warm climate more than shorter ones, but this is one of the explanation that has been given for the shorter stature in pygmies.
    2. invasions from the South. Southern European Countries have probably seen more flow from Middle East and other African/Indian, where the climate is even warmer than in South Europe, accelerating the effect explained in the previous point.

  • Robert

    “How can my children be inches taller than they would otherwise be with identical genes and environment”

    This article refers to a study with an example of an epigenetic effect on coat color over at least one generation of mice:

    “Epigenetic modifications include, among others, the methylation state of the DNA and the proteins that package the DNA into chromosomes. The epigenetic state of the genome is established in early development and is generally thought to be cleared between generations.

    However, there is increasing evidence that some parts of the genome are not cleared leading to transgenerational inheritance of epigenetic state in these specific parts, termed transgenerational epigenetic inheritance. Furthermore, the establishment of the epigenetic state at these loci can be modified by environment. For example, the epigenetic state of the agouti viable yellow locus, containing a gene contributing to coat colour in mice, can be manipulated by altering the diet of the pregnant female. At this stage, these effects have only been studied in F1 offspring. However, epigenetics does provide a possible mechanism for the transgenerational effects reported by Pembrey and co-workers.”

    http://www.nature.com/ejhg/journal/v14/n2/full/5201567a.html

    Perhaps there is a neo-Lamarckian mechanism acting on Italian height genes. Grandparents shifting their rides from Vespas to Topolinos unleashed a slew of epigenetic effects! :lol:

    Perhaps more likely is that as soon as there was the elimination of widespread infant malnutrition in Spain and Italy during the 1950′s intense sexual selection of taller mates occurred which increased average heights in the cohorts born in the 1970′s.

  • Sandgroper

    Someone needs to explain the Dutch, because they started out short in the 17th Century, and they just keep getting taller. It might have levelled out recently, I don’t know, but if so, it would have been very recent.

    One of my tennis team mates is a young Dutch guy who is 6’1″, and he told me he was the shortest kid in his class. He said they are now administering growth inhibitors to Dutch kids because excessive growth has started to cause spinal problems. Which seems kind of drastic, so I assume this is not a trivial problem.

    He put it down to high dairy intake. But surely the Dutch have had that for millenia?

    That seems like a case of transgenerational epigenetics, but continuing seemingly indefinitely, not for just a few generations.

  • ackbark

    On getting back to white Americans and their declining increase in height relative to Europeans,

    I would suggest it may have to do with the recent deployment of a wide variety of additives in processed food and excesses of sugar and trans-fats.

    And not just the things themselves but the sheer variety of them our bodies have never before encountered.

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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

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