How would a group of people inspired by European ethnic groups maintain their lighter skin in a desert climate?

Question

Messing around with different aesthetics and groups for this story, and I'm wondering how to go about this. I wanted to do a setting where a region is full of basically ancient Egyptian inspired cultures but the climate is colder instead of a hot arid desert. I've seen it speculated that certain groups were able to maintain their darker pigment even in colder climates if they kept a diet of vitamin D and were still in a region exposed to sunlight in a place with high latitude (correct me if these aren't entirely accurate).

Now I'm working on a group in the same world that are basically desert "Vikings". most of the suggestions I've been given end up making them basically Middle Eastern ethnic groups, but I wanted to keep their ethnic background and phenotype Scandinavian-inspired.

Basically for these two groups I want to keep the selective pressures that cause pigment changes. Would the opposite of the vitamin D thing be if their culture ate a lot of folate? I figured since in a hot and exposed place UV destroys folate stores, they would have to have folate diet that would make up for this. Would they have to be recent migrants to the region for it to be plausible, or can it still be plausible for them to be natives to this hot desert region? Can the elements that create this scenario be realistic, or do they need to be more fantastical? like say, fantasy foods or circumstances that would cause this.

Answer 1

Sir Cornflakes is correct about not mixing with darker-skinned people, but how did humanity's skin color change in the first place?

*Evolution is not quite "survival of the fittest" as it is "reproduction of the fittest". As long as your light-skinned people are able to naturally reproduce (have children) and avoid intermixing with darker-skinned populations, they will maintain their color just as if they were living anywhere else in the world. Specifically, conditions such as skin cancer or nutritional deficiencies triggered by their new climate must not reduce fertility or otherwise reduce individuals' ability to reproduce. If they do reduce fertility, members of the community with slightly darker skin will gain an advantage, and the community will tend to darker skin over time.

The above reason is why white people who have lived in Florida for generations are still as naturally white as those who never left Europe.

The above reason is also why conditions of the elderly such as Alzheimer's Disease will most likely never "evolve away". By the time someone becomes impaired by Alzheimer's, they have almost certainly had all of the children they will ever have and so there is no evolutionary pressure to avoid genes that might contribute to it. Conditions that kill in childhood, affect a person's ability to find a mate, or that directly reduce fertility may all be subject to evolutionary pressure as affected individuals will likely have fewer children and descendants than unaffected individuals.

Answer 2

People who live in the desert might wear very little clothing because of the heat, or maybe wear a lot of clothing because of the heat.

I notice that Arabs wear a lot of clothing to cover most of their bodies in the Arabian Desert.

And I think that Berbers also cover up a lot in the Sahara Desert.

Thus Arabs and Berbers probably don't get a lot of sun tan since most of their skin is covered most of the time. Thus the sun probably doesn't darken their skin much darker than whatever their natural skin shade is.

So some desert dwellers who wear a lot of clothing probably would be protected form the sunlight except on their hands and faces. Of course fictional desert dwellers could wear gloves on their hands. And Taureg men wore face veils like Muslim women did. Possibly fictional desert dwellers could wear face veils masks or very broad brimmed hats.

I once read about a battle where a group of Taureg swordsmen made a mounted charge on French colonial troops armed with rifles. The Tauregs lost, naturally. And it was said that the corpse of the leader of the attack had white skin. So apparently some Tauregs have naturally pale skin, which doesn't tan much due to be being covered up.

So there is no scientific law prevent people with light skin from moving to desert areas, and covering up to protect themselves from the sunlight, and so avoiding becoming tanned.

And as long as they don't intermarry with darker skinned people, their skin will retain its original light shade. It takes many thousands and tens of thousands of years for a human group to have much biological adaptation to new surroundings.

Answer 3

Perhaps the desert sun is so hot and devastating (as is the reflection off the sand), that people can't go out during daylight hours. Even if they went outside during daytime while clothed, the ambient heat would essentially bake them. Since they only go out at night time, then they'd maintain their light pigment. Because daytime in that location is so powerful, that's also when animals and wildlife would be out and about, so it's the perfect time for the vikings to hunt to sustain themselves.

They could have dug into a limestone mountain side or made pueblos with a nearby river/ocean inlet. It's possible since they arrived from the ocean as vikings that there were/are whirlpools that prevent them from leaving their coast, so they've been marooned there for centuries and built a small community.

Answer 4

SPF100 Sunscreen.

That's probably the most realistic answer.

Answer 5

There is no "evolution on demand".

The people will maintain their light skin for a long time just because they don't mix with dark-skinned people. They may suffer from sun burn and skin cancer, but this does not trigger mutations to darken their skin. Also note that defect mutations with the effect of lighter skin are frequent, but constructive mutations with the effect of more melanin production and darker skin are rare.

Native American people settle equatorial South America for more than 10k years and didn't become as black as Africans or people from Southern India in that long time span.

Answer 6

This is a very, very simple problem. We look at how skin changes color, and then identify how we could prevent this.

It is estimated that it takes as little as 100 generations for a race's skin color to acclimatize to a new geographic area. In the past, skin turned darker because the lighter skinned people died of skin cancer before they could breed. Skin turned lighter in low light areas because the dark skinned people suffered from many health issues due to vitamin D shortage.

If you apply sun screen (or cure cancer) and provide vitamin D, you remove the selection pressure that makes this a selection criteria.

Note that 100 generations is the extreme low end, which involves massive selection pressure (which is to say, lots of people dying), and is more than 2000 years, so you probably don't need to concern yourself with this. If your white people are privileged, then such selection pressure would probably be swamped by the benefits of that privilege.

Answer 7

Setting aside the diet and pigment thing (incorrect!)

Your albino desert vikings have fur.

https://en.wikipedia.org/wiki/Albinism#/media/File:Snowflake_-_Barcelona_Zoo_White_Gorilla3.jpg

Skin pigment protects from the sun in sunny locales. But if you have fur you don't need pigmented skin; the fur will protect you. White fur keeps the desert vikings cooler because white reflects more light energy. Instead of clothes they have elaborate fur braids and hairdos. And they go around in the buff because it is hot, but you can still make the anime because they have fur. They are desert yeti vikings; yes.

Answer 8

Skin color is almost entirely an adaptation to latitude, not biome. In particular, each latitude has its own local equilibrium between less melanin producing skin cancers and more causing problems with Vitamin D generation (Rickets). Whatever point that equilibrium is, that's going to be where residents' skin melanin levels will tend to equalize at.

So if you want naturally light-skinned desert dwellers, you either need a high-latitude desert, or a planet that receives less UV radiation than ours.

To give an example from our own planet, the Gobi Desert is relatively high-latitude (about the same as latitude as southern Europe). Most redisents are Mongolians. The best photo I could find showing the faces of multiple Mongolians is this promotoinal photo of the Mongolian rock band "The Hu"

Different people are different of course, and there are some ethnic coloring differences, but these skin darknesses in general wouldn't look out of place in much of southern Europe.

Answer 9

Predation is more dangerous than skin cancer

Your desert is inhabited by incredibly dangerous predators which rely primarily on eyesight to hunt their prey. Because the sand is white, people with white skin have better natural camouflage. Sure, black skin might offer better protection against the sun, but as long a you are more likely to be eaten for having black skin than you are to die of skin cancer for having white skin, then the white skin will still be more selectively fit.

Some alternatives along the same lines could be that predators simply prefer easting dark skinned people. Maybe they taste better, maybe they are easier on the digestive system, or maybe they just more closely resemble the predator's actual preferred food source... like if they like eating chimpanzees, and are more likely to mistake a black person for a chimp.

Answer 10

A rite of passage that favours the fair

Every would-be Viking captain is sent to the farthest reaches of the frozen North, in the ultimate test of survival. The darkness up there is a serious threat to life and the darker skinned mixed Viking/Africans survive less of the time.

Captains naturally have more far more children.