Khemehekis wrote: ↑02 Aug 2024 06:31 I want to create a number of Kankonian races [...] and then have them all interbreed with each other and migrate.
If they're interbreeding then they won't remain distinct "races" for more than a couple of generations.
Melanin in dark-skinned populations like Sub-Saharan Africans, Australian Aborigines, and Fijians protects people in hot areas from the heavy helping of sunlight they get. Being light-skinned, on the other hand, is useful in cold areas like Scandinavia because it lets more sunlight into people's skin, allowing them to get the vitamin D they need.
I've also seen it suggested that melanin has some role in reducing insect bites (or their effect?) though I can't remember the details.
It's likely that certainly pale skin and probably very dark skin are at least partially the result of sexual selection.
3. As per Allen's rule, the general evolutionary law that explains why polar bears are so stocky, people near the poles will be squatter in body shape than people near the equator, who are likely to the tall and lanky (like the Dinka). This reflects the fact that a round body shape helps people and other life-forms conserve heat better.
An important caveat to this is that those living in high-altitude areas tend not to be tall. But also, I wouldn't be too dogmatic about this: Norwegians live a long way from the pole and tend to be quite tall, whereas Twa live very near the equator and are extremely short ("pygmies").
4. Long, thin nostrils help desert-dwellers by keeping them from breathing in so much sand.
5. Similarly, epicanthic folds protect eyes from sandstorms and dust storms.
I'm extremely skeptical. Particularly about the eyes - I'm not sure why having the fold on one side rather than the other would make a huge difference to sand, and in any case I'm not sure there's any correlation between the distribution of eyefolds and the distribution of sand. At all. The Sahara has more sand than Vietnam!
1. What are the advantages and disadvantages of the different hair textures: straight, curly, wavy, frizzy?
2. For that matter, why do some places have more variation in hair texture than others? How come East Asians almost always have straight hair and sub-Saharan Africans frizzy hair, while you see a lot of different hair textures in the Middle East or Southern Europe?
It's not known why early humans evolved kinky hair, although they probably did: chimpanzees and gorillas have straight hair, but most branches of humanity have kinky hair.
One theory for this is that kinky hair allows the same level of "coverage" (blocking light from the skull) with lower density (allowing more heat transfer - a sponge rather than a felt blanket), and that this was the optimal way to keep the skull cool in savannah conditions. But this is obviously speculative.
In terms of diversity, it seems that kinky hair is the primordial state, and straight hair is a later invention in east asia. Subsaharan Africa, where there is most genetic diversity by far (all non-africans are more related to each other and to certain africans than those africans are to other africans) has almost universal kinky hair; likewise, melanesians, who are the most direct and unmixed non-african descendents of early migrations from africa, almost always have kinky hair. [in a broad sense, although I've read people say that melanesian hair actually has a slightly different structure from typical african hair]. Straight hair is associated with east asia, and the americas (settled entirely from east asia).
Europe and south asia have more mixed hair patterns because they are more racially mixed between east asian and non-east-asian populations. Or perhaps because the mutation actually began shortly after the migration into west asia, whence european and south asian populations, but only reached its extreme form in the subsequent migration to east asia (with back-migration from east asia then muddling up the picture further).
Why did east asians develop straight hair? Nobody knows. Maybe it looked sexy.
3. Why are thin lips, medium lips, or full lips selected for in certain parts of the world?
4. What are the advantages, if any, of the different nose types?
Random chance, sexual selection, and frankly great over-emphasis in stereotyping.
5. Will populations with epicanthic folds necessarily have monolids?
I'm not sure what you mean. Humans have both upper and lower eyelids, but only one of each per eye.
6. Are there any "survival of the fittest" advantages to different head shapes? (There's a popular theory on the Internet that head shapes correspond to different personality types, but that reeks of pseudoscience.)
It's alarming that you only say it "reeks of pseudoscience" rather than saying it's both total nonsense and obviously racist. It's not something even worth raising, and it's alarming that you frequent the parts of the internet where this sort of racist insanity is "popular".
7. Why is metabolism better in some ethnic groups than others? For instance, people always say that the Japanese have great metabolism.
What does "better metabolism" even mean? Humans all have basically the same metabolism - we eat the same sort of chemicals, and use them to produce the same chemicals, and to produce energy in the same ways. Small variations in metabolism can evolve to reflect circumstances: populations that rely on milk have evolved to be able to metabolise milk as adults (otherwise it produces bloating and diarrhoea); populations that rely on alcohol as a disinfectant of water have evolved to metabolise alcohol more effectively (so it takes more alcohol to produce symptoms of poisoning, including paradoxical addictive behaviours).
Basal metabolic rate - the amount of energy processed in a given span of time - does vary between individuals, but as a function of weight: heavier people have faster metabolism and lighter people have slower metabolisms. [the metabolic rate is the result, not the cause, of the weight difference]
8. Are there any "survival of the fittest" advantages to high cheekbones, or is that one of those traits like blue eyes or freckles or baldness?
I can't think why there would be.
9. Finally, what makes populations more likely to develop hair that is dry, normal, or oily? I can't find any information about oily hair on Wikipedia (if you type in "oily hair" it redirects to the article [[sebaceous gland]], which doesn't even have the phrase "oily hair" anywiere in the body of the article!)
I would avoid terms like "normal" in describing racial differences.
But I'm not sure oiliness is a racial difference anyway. In general, the amount of sweat and its contents can be affected by hormones, which is why teenagers tend to be stickier than adults. Hair washing is also significant. Perhaps hair density might affect how effective washing is? And soft, fine hair (thinner strands) looks shinier and feels silkier (or "oilier" perhaps) than thicker, coarser hair.
