How did human skin colour change so fast...

How did human skin colour change so fast, was it because of our innate intelligence allowing us to adapt to new environments or just "lol random mutations"

Other urls found in this thread:

ncbi.nlm.nih.gov/pmc/articles/PMC3491390/
youtube.com/watch?v=y8Lw-KWD31k
twitter.com/NSFWRedditVideo

a few alleles, most importantly tyrosinase gene variant + founder effect

explains many diversity questions

I've heard it was due to the fact that human migration moved from Africa (a place of much direct sun radiation) to the northern hemisphere where sun radiation is not as direct. This decrease in the UV radiation exposure evolved large amounts of melanin out of the body's design because it was no longer necessary. And apparently this migration happened quickly in the course of human history

>evolved melanin out of the body's design because it was not longer necessary
that's a teleological argument

there must be a real reason other than "it would be good"

the genome doesn't know any of that

i believe that some north africans who had lighter skin migrated out of africa and white skin ended up having a bigger frequency in the new offshoot due to bottleneck effect

Light skin is better suited to regions farther from the equator, because less sunlight year-round means your body needs to create vitamin D more effectively.

Lighter skin means we can absorb UV radiation (and hence produce vitamin D) more efficiently. We need vitamin D for our bones (amongst other things), and having strong bones was a significant advantage back then. For the same reason, Europeans have less dense bones than Africans, as it was imperative to use vitamin D as efficiently as possible.

UV radiation index.

Different prototypes optimized for respective environments then seeded there.

>our innate intelligence allowing us to adapt to new environments
You can use all the intelligence you want to adapt, you can build stuff and teach your progeny to do the same but that isn't going to influence your dna.
Mutations are always random, nothing to lol about since most mutations end with bad results.
Not always.

>implying

Why do so many scientists fall for liberal memes?

Go shave an ape. Or any monkey. Just do it. Underneath that dark hair is what? That's right, light white skin.

"We were all black cause we came from Africa durr" WRONG! We were all TAN. Those that moved north got lighter, those that stayed towards the equator got darker.

actually, if you take into account a rational man's ability to select his bitches wisely, intelligence can greatly influence his dna.

>here you go my mongol son! choose a wife from these clans. my father taught me just as his before him: look for one with a flat nose so the wind doesn't cut her.

saw this in the movie Mongol

>Those that moved north got lighter, those that stayed towards the equator got darker.

k but why tho?
are you reading the thread?

Anyone know how many generations the very black - like ace of spades black - from Africa would take to morph into white people? I've always wondered, just because so many are suddenly in the northern hemisphere now. It makes me a bit nervous because lack of vit D processing in the body leads to immune system weakness. I worry about many things, famine, resource depletion but black plague scares the shit outta me, I really don't want it being a white man. I am not a storm wiener, it's a legit concern.

>several thousand years
>fast

Sexual selection for lighter skin in women (more neotonus) btw...

Humans can also get Vitamin D from just eating foods with vitamin D in them. Being able to synthesise it from sun UV exposure used to be super important to human survival, but then we domesticated cows and chickens and invented fishing boats.

In the 1950s we started deliberately adding it to Orange Juice and Soy Milk so vegetarians would stop giving birth to kids with fucked up bone deformities.

>change so fast
How fast is "so fast", fgt pls

>How did human skin colour change so fast,

More than likely it didn't, there probably was a base "range" of pigment variation. These pigments revealed themselves through chemical reactions involving exposure to uv radiation, diet, thermoregulation, water/oxygen transport and stress, pH acidification in skin and the extremes (very dark, very light skin) came out through cluster mutations via environmental response and proliferated from regionally isolated sexual selection.

ncbi.nlm.nih.gov/pmc/articles/PMC3491390/

Are we all the same species?

A shaved chimp will slowly develop dark skin meaning the idea hominids were nigger colored might be plausible.

Anyone also notice the smooth skin mammals in Africa also have dark skin?

No Eurasians and Africans are different species that can interbreed.

>i believe that some north africans who had lighter skin migrated out of africa and white skin ended up having a bigger frequency in the new offshoot due to bottleneck effect
That still doesn't explain why some north africans had lighter skin.

How would intelligence help people change their skin color?

Yes, we are all are the same species. Despite the differences the same genetic tool set is present in all populations. This is also why we categorize by haplogroups because we measure gene clusters and compare them region by region on a statistical, age and distance bases.

For example melanocytes which regulates skin pigmentation is present in all populations but are distributed differently between populations. Yes, the distribution between African populations and European and Asian are formatted differently. With European and Asian populations being more "similar" to each other in melanocyte formatting but that similarity is apparently indicative of a parallel adaption in pigment lightness via convergent evolution.

In other words Europeans and Asians share a more recent ancestor but the occurrence of their pigment colors is independent showing their own method of adapting light skin with a possible correlation that favors distance from equator.

Evolution is a meme. "Scientists" use it to explain away anything they don't understand.

Oh. K. Guess it makes me feel a bit better. I thought maybe Eskimos are very dark because they have a pure diet of fish and sea creatures.

Still, how long are we taking here for black to white mutation? 3 generations, 10? Anyone every studied that? I know I tan up real good down by the equator, shit even in summer if out and about a lot the tint comes fast.

No priest worth his salt would say that.

I just wonder how long it would take for humans to split into difference species if everyone stops breeding interracially

I can only believe that if at one point in evolution the skin was white due to random mutations and the less exposure to sun radiation of the new population just forced their body to drop some genes - what makes you think the genes magically just know what's a good mutation to get...

Evolution doesn't happen at a constant rate. It depends on a lot of factors such as the size of the population and the pressures on it. Modern day humans have diets rich in Vitamin D, so nobody is going to evolve lighter skin to get more Vitamin D from UV synthesis.

> I know I tan up real good down by the equator, shit even in summer if out and about a lot the tint comes fast.
You know Lamark was wrong right? Tanning won't make your kid's skin any darker.

Darker skin -> less vitamin D -> lower average fitness -> reduced survival of dark skinned individuals in the north over thousands of generations -> light skin

Vitamin D deficiency from poor sunlight far from the equator would have meant rickets, hypogonadism and cancer for dark-skinned humans

The sickly, depressed, testosterone-deficient, immune-deficient, rickets-stricken darker offspring would be selected against, either by sexual preference or they would have died easier

so if we make the world colder and cloudier we can eliminate all blacks through evolution?

Step down whitey, everyone knows blacks have the biggest bones

because the sunlight fried the niggers skin and brains, that's why their dark. take an entire white colony and settle them in the congo and they will turn to niggers in a few thousand years

Cloudier yes, cold has nothing to do with it. And actually, UV can get through thin clouds pretty easily and at tropical latitudes the amount of air it has to pass through at mid day is vastly less all year round than above or below the tropics. In the northern hemisphere for example, by halfway through October there's no point in the day where enough UV makes it through the atmosphere to even begin vitamin D synthesis, let alone give a sunburn.

Thus, as well as cloud seeding you'd need to disperse some kind of UV absorbent or reflectant into the atmosphere, or drastically thicken the ozone layer. A space-based geosynchronous UV filter might work as well. Either way you'd need these things up and running for about 80,000 years for a fairly isolated population of humans numbering in the tens of thousands, so to begin permanently changing the gene pool of millions of Africans you'd need to add another zero on to that probably. Maybe that's excessive, but I'm ballparking here.

Either way good luck senpai, the white race is counting on you.

youtube.com/watch?v=y8Lw-KWD31k

Thank north africans for your existence. If it wasn't for their adaptability we wouldn't exist