Before asking this question read

though neither posed the same question or provide the answer to the present question.

In Modern Human Diversity - Skin Color published by The Smithsonian National Museum of Natural History the document in pertinent part states

As early humans moved into hot, open environments in search of food and water, one big challenge was keeping cool. The adaptation that was favored involved an increase in the number of sweat glands on the skin while at the same time reducing the amount of body hair. With less hair, perspiration could evaporate more easily and cool the body more efficiently. But this less-hairy skin was a problem because it was exposed to a very strong sun, especially in lands near the equator. Since strong sun exposure damages the body, the solution was to evolve skin that was permanently dark so as to protect against the sun’s more damaging rays.


The darker skin of peoples who lived closer to the equator was important in preventing folate deficiency. Measures of skin reflectance, a way to quantify skin color by measuring the amount of light it reflects, in people around the world support this idea. While UV rays can cause skin cancer, because skin cancer usually affects people after they have had children, it likely had little effect on the evolution of skin color because evolution favors changes that improve reproductive success.

There is also a third factor which affects skin color: coastal peoples who eat diets rich in seafood enjoy this alternate source of vitamin D. That means that some Arctic peoples, such as native peoples of Alaska and Canada, can afford to remain dark-skinned even in low UV areas. In the summer they get high levels of UV rays reflected from the surface of snow and ice, and their dark skin protects them from this reflected light.

Cases: Lighter skinned populations who migrated to tropical regions (for example, Mennonites in Belize, Boers in South Africa, Belgians in Congo (DRC)) and darker skinned populations which migrated to non-tropical regions (for example Africans in Britain, Africans in the northern U.S. States and Alaska, and Africans in Canada), where the diets of the populations take on the diets which in part led to the specific pigmentation, and the sun applies the same amount of light (UV; other spectrums) to the population as the population where darker or lighter skin adapted, or evolved.

Given the parameters provided, a lay person might conclude that they should be able to migrate to a specific tropic or non-tropic region of the world, take on the diet which led to the melanin production and skin pigmentation which the article states influences adaption or evolution, and over N fixed generations, or an unknown period of time, though eventually, their skin pigmentation will adapt or evolve to the population planners' desired pigmentation; that melanin production and skin pigmentation is not fixed, that evolution and adaptation as to skin pigmentation is continuously ongoing in the human population on Earth circa 2019 CE - and the claim is capable of being reproduced, observed and objectively measured using the scientific method.

Have any scientific studies been performed which substantiates or refutes by observable measurement the theory or claim that environment and diet have an effect on melanin production and skin pigmentation within the scope of any timescale ("One generation, two generations, ten generations, 10-20 generations")?

  • $\begingroup$ I downvoted because this question, despite its length, seems to strongly misunderstand evolution and because I suspect it is not asked in good faith. See a good reference on basic evolution like evolution.berkeley.edu/evolibrary/home.php $\endgroup$
    – Bryan Krause
    Feb 16, 2019 at 0:51
  • $\begingroup$ @BryanKrause Gather what evolution and adaptation are. Have no "faith" in anything. The question asks for facts: have any studies been performed to substantiate the claim presented as to melanin production and diet having measurable impact and influence over skin pigmentation; which obviously can be proven true and correct or false by examining the cases provided as example at the question. $\endgroup$ Feb 16, 2019 at 0:53
  • $\begingroup$ "In good faith" is a phrase not related to the typical meaning of "faith" as religious belief. Saying I don't think your question is in good faith means I think you're probably asking it because you want to infer something about race, rather than having any actual interest in human evolution. $\endgroup$
    – Bryan Krause
    Feb 16, 2019 at 0:55
  • $\begingroup$ The claim is that melanin production may have been selected against in higher latitudes and selected for in lower latitudes. The evidence is that populations near the equator tend to have darker skin than those far from the equator, across multiple continents. $\endgroup$
    – Bryan Krause
    Feb 16, 2019 at 0:56
  • $\begingroup$ @BryanKrause Am fully aware that "race" has absolutely no basis in science and "it is a made-up label", etc. Do not self-identify with any fictitious "race". Am asking about the actual science. Yes, have an interest in evolution, though am not compelled to agree with every assertion made under the banner of evolution or adaptation. "The evidence is that populations near the equator tend to have darker skin than those far from the equator, across multiple continents." Is that true for Mennonites in Belize? The question is: Is that process ongoing right now? $\endgroup$ Feb 16, 2019 at 0:56


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