5 votes

Did Europe have more mutations through its history?

This is something weird to me. I think skin color is pretty diverse no matter where you go, or at least, I don't know enough to say otherwise. But take hair color. Europe has more diversity in hair color than almost anywhere else. Same with eye color. Why is this? Is it just because I interact with more people of European heritage on day to day business, or has Europe actually had more mutations which affect hair color, eye color, etc? Or is it that Europe, being a crossroads has had more people immigrate through it.

If this is racist, it's unintentional, this is just an observation, which I've been unable to find an answer to.

If you have an answer, a link to a paper would be great.

Edit: A point against what I just wrote that I thought of: Asia has both mono and double eyelids, which is something Europe doesn't have. Native americans don't count either for or against, since they immigrated fairly late in a small group, which also explains why almost all native americans are type O

12 comments

  1. [5]
    PendingKetchup
    (edited )
    Link
    There's definitely more genetic variation inside of Africa than outside of it, or between Africa and the rest of the world. Only a few people left Africa, on a population scale, and they didn't...

    There's definitely more genetic variation inside of Africa than outside of it, or between Africa and the rest of the world. Only a few people left Africa, on a population scale, and they didn't have enough of a cross-section of the population to bring all the variation with them, or enough of a population size once they left to retain it. Genetic variation is mutations in aggregate; each mutation occurs in an individual, and then rises and falls in frequency in the population over time, until it either goes to fixation (nobody without it is left) or it goes extinct (nobody who has it is left). The bigger your population, the more genetic variation you can hold at a steady state (where mutations fix or go extinct as fast as they occur). Right now humans are way far away from the steady state, as our population has exploded in (evolutionarily) no time.

    I don't think the rate of new mutations could be much higher in Europe either. Here's a paper finding maybe a 5% difference in mutation rate between populations, which isn't a lot, especially compared to existing variation stocks. White people just keep better track of the interesting traits that are found in Europe, and don't actually look hard enough to identify interesting traits in Africa. This is a white gaze problem.

    8 votes
    1. Silbern
      Link Parent
      Yeah, I think it's more likely blond hair is common in northern Europe because of a lack of genetic diversity, not despite it. Other regions of the world with similarly low sunlight patterns don't...

      Yeah, I think it's more likely blond hair is common in northern Europe because of a lack of genetic diversity, not despite it. Other regions of the world with similarly low sunlight patterns don't exhibit comparable mutations, and the one part of the world that does - certain regions of the Pacific - also suffer from a lack of genetic diversity, owing to small populations that are greatly isolated from each other. Blond hair tends to be naturally recessive, and it shrinks or even disappears nearly entirely in more diverse regions of the world, even when they contain Europeans or people of European descent (like the US, Canada, southern France, etc. where blond people are 25% or less instead of 80+%), which I think is pretty significant.

      3 votes
    2. [3]
      grungegun
      (edited )
      Link Parent
      This could be good. However, in my case, I'm wondering about functional phenotypes, so maybe this isn't as applicable? For instance, we know that the notion of races can't be supported...

      We studied the pattern in noncoding regions, because they are less affected by natural selection than are coding regions.

      This could be good. However, in my case, I'm wondering about functional phenotypes, so maybe this isn't as applicable? For instance, we know that the notion of races can't be supported scientifically., However, this site, notes that functional regions regarding hair color and eye color do show unusual variation.

      This is a white gaze problem.

      So what would be the equivalent for someone in asia or africa? So, like to explain to someone who wanted to distinguish beyond the cross-race effect, I would point to variation in hair color, air texture, freckles vs tan, and variation in eye color as easy distinctives. What distinctives would someone else point out to me? (I noted the mono-bi lid distinction already for Asia. Also, hair texture in Africa.)
      Where I live particularly, it's a bit harder, since everyone around is tall and blonde with blue eyes, so locally it is a bit difficult. (midwest)

      1 vote
      1. [2]
        PendingKetchup
        Link Parent
        The rates at which mutations arise are the same across functional and non-functional sites. But functional regions are subject to selection, which will turn into ascertainment bias when you're...

        This could be good. However, in my case, I'm wondering about functional phenotypes, so maybe this isn't as applicable?

        The rates at which mutations arise are the same across functional and non-functional sites. But functional regions are subject to selection, which will turn into ascertainment bias when you're trying to measure the base mutation rate (because mutations happened, and mostly got selected against, so they went away, so you didn't see them, so you couldn't count them). So to measure the base rate at which new variants arise, you want to look at the non-functional sites.

        I'm not really sold on that Frost reference being particularly high quality. It looks like just one guy (when I would expect a team or a research group), wandering through several fields (which he can't possibly be an expert in all of) trying to support an idea he already likes (instead of trying to falsify it like a good scientist).

        It chains together like 3 or 4 not-really-substantiated-by-evidence assertions about how human social dynamics would have worked in the Ice Age tundra, all of which have to be true to really support the proposed explanation. "Pick a spouse from a lineup of strangers" as played by undergrads or whoever is not shown to be a valid test for sexual selection in the Ice Age tundra, and moreover this writeup is trying to make the phrase "a brunette" happen in scientific discourse.

        It describes a "possibility" as "evidence" as it leans on an unpublished (and hence un-peer-reviewed) study of finger length, which came up with a correlation (as opposed to evidence of causation or a mechanism), trying to support the assertion that hair or eye color is "mildly sex-linked". I think Frost here may mean "influenced by hormones"; as far as I can tell, Frost is the only scientist who has ever used the phrase "mildly sex-linked". I can't find any known hair or eye color genes on the X chromosome, which is where genes have to be for their traits to be actually "sex-linked". If you want evidence that estrogen and testosterone affects hair color, plenty of people take estrogen or testosterone; why not study their hair instead of measuring fingers as a proxy? Why would only prenatal exposure produce an effect?

        When I plug the title of the paper the page is about into Google Scholar, one of the pages that Google Scholar thinks is the paper is actually a forum post on a "Germanic", seemingly-Stormfront-adjacent forum.

        These all ring my alarm bells. Plus, ask this writer how that sexual-selection-for-less-common-colors theory is working out for her.

        What distinctives would someone else point out to me?

        I couldn't tell you. I also suffer from the white gaze problem. That doesn't mean they're not there, but you might not find much on the Internet, in English.

        2 votes
        1. grungegun
          Link Parent
          Thanks for the response. I couldn't find much about this online. The reason I ask is because, while I knew that blond hair existed in other cultures as well, like in Oceania. Looking through the...

          Thanks for the response. I couldn't find much about this online. The reason I ask is because, while I knew that blond hair existed in other cultures as well, like in Oceania. Looking through the examples, it looks like every culture had a chance to have prevalent spread of unusual hair colors, etc. The only distinctive I can think of is that maybe ancient Europeans were racist or had some other factor leading to a weirdly wide spread of a trait that could have been stopped if no one had gone out with the first blue-eyed person. Maybe the blonde gene that shows up in Asia and Africa has a slower rate of spread. Anyway, the three viewpoints people have cited seem to be that there is no distinctive about Europe (solely white gaze), it was a crossroads (migration + it was close to fertile crescent), or blonde hair was correlated with health (anecdotally, I think this is false. I am guaranteed skin cancer, and I'm blond), so basically no consensus, just researchers

          To the article you posted, I sympathize with the author. People are supposed to be more psychologically comfortable with what they are familiar with, so that would contradict the sexual-selection-for-less-common-colors theory. If shown the images without context on the results, I would have guessed popularity completely wrong.

          About the white gaze problem, oh well. I may be able to travel a bit in the future, which should be eye-opening.

  2. [2]
    patience_limited
    (edited )
    Link
    You might want to refer to this: https://en.wikipedia.org/wiki/Genetic_history_of_Europe It's not so much a question of a difference in mutation rate, as isolated founder populations after the...

    You might want to refer to this:
    https://en.wikipedia.org/wiki/Genetic_history_of_Europe

    It's not so much a question of a difference in mutation rate, as isolated founder populations after the last glacial cycle, interacting with multiple waves of migration, diseases, and eventual selection for people who could tolerate agrarian diets and varying levels of sun exposure. Pale skin and light hair were surprisingly recent developments.

    Edit: There are some weirder recent sortations - religious or cultural endogamy in various groups, e.g. Orthodox Christians, Ashkenazi Jews, Roma, and others; the packing of ethnicities into national borders post-WWII (see Tony Judt's Post-War for the story of how new ethno-states were created from previously diverse populations).

    6 votes
    1. grungegun
      Link Parent
      Cool, that kind of agrees with my speculation on Europe migration, since it is in the middle of two continents.

      Cool, that kind of agrees with my speculation on Europe migration, since it is in the middle of two continents.

  3. [4]
    chas
    Link
    There's clearly some biological reason why blonde hair is poorly suited for warm climates. The further South you go from Finland, where the majority of people are blonde, the darker the hair...

    There's clearly some biological reason why blonde hair is poorly suited for warm climates. The further South you go from Finland, where the majority of people are blonde, the darker the hair color. Up close, it looks like diversity, but, on average, it's a smooth transition, as you can see from the map in this article: https://bigthink.com/strange-maps/214-the-blonde-map-of-europe

    5 votes
    1. [3]
      Silbern
      Link Parent
      Not necessarily. Many other northern populations, particularly the indigenous people of Canada and Russia, don't natively have blond hair at all afaik, and there are populations of Pacific...

      Not necessarily. Many other northern populations, particularly the indigenous people of Canada and Russia, don't natively have blond hair at all afaik, and there are populations of Pacific islanders that independently developed it (and still sustained it). A commonly cited reason is that blond hair enables more vitamin D to be collected, but the blondest populations in Scandinavia tend to be regions where people also consumed fish in large quantities, which is one of the few sources in nature that naturally has a lot of it. Further south, in Germany or France for example, the total supply of sunlight isn't all that much greater (if at all), yet blond hair drops off pretty substantially even over a relatively short distance.

      It doesn't seem to be a big disadvantage or advantage either way given its inconsistency, and I think the rarity has more to do with the fact that lighter hair colors tend to be highly recessive, so you need a relative lack of genetic diversity to continuously sustain it in high quantities. Europeans tend to exhibit many other highly recessive traits / disorders, and I hypothesize that blond hair is just one more of the pot.

      6 votes
      1. [2]
        grungegun
        Link Parent
        I'd agree with you. However, chas's position appears to be weirdly popular.

        I'd agree with you. However, chas's position appears to be weirdly popular.

        1 vote
        1. chas
          Link Parent
          Eh, I'm not married to that position. It's not my area of expertise, so I'm happy to defer to Silbern. Besides, the part I find most interesting is the gentle gradation in hair color from Finland...

          Eh, I'm not married to that position. It's not my area of expertise, so I'm happy to defer to Silbern. Besides, the part I find most interesting is the gentle gradation in hair color from Finland outwards.

  4. ohyran
    Link
    We banged a lot of neanderthals? I don't know. Just wanted to add something - the little corner of the world I'm from is famous for people having a high tolerance for lactose, AND one of the...

    We banged a lot of neanderthals?

    I don't know. Just wanted to add something - the little corner of the world I'm from is famous for people having a high tolerance for lactose, AND one of the freakiest things ever: small children lacking the tastebuds (EDIT: ment "couldn't taste" its not like part of our tastebuds are gone) for sour.

    When I was a little kid we moved to different warzones (dad was a soldier) and during the Turkish invasion of Cyprus we got more or less forcefed lemons by the old dudes down at the bar daily just so they could watch me and my baby brother munch down on them without even flinching. Look there was a war on, entertainment wasn't exactly readily available.
    (That and that they got freaked out by our hair being white-blond when we got too much sun, like I said: it wasn't exactly much in terms of entertainment otherwise)

    4 votes