how do other races get dark?

Originally posted by AfrikaJamaika Originally posted by think Depends how pale you are. Most people arent "pale" as in pure White anyway. I just burn, so ive never been concerned about tanning. Besides if i did decide to get a tan, I would get skin cancer ive already got a mole that i gotta watch. oh ok what i want to know is how did the light skinned people of ancient times the the Arabs, and the Caucasians not get sun burnt back then while they were in Africa? NOTE TO EVERYONE: With the Global warming approaching i think its best that everyone of all races where some time of sun block at all times ITS GONNA GET HOT! From what i hear....

Guyz, I'm freaking out have you ever heard about Darwin?

Lets go back in time, before Darwing some guys (namely Lamarck) had already some ideas about evolution with the difference that there was some kind of learning by doing process going on. In our case it would be: daddy and mum are very white but for some reason they move to Africa get very tanned and when I'm born I've got the message and I'm somewhat darker than them.

Of course you have a problem here and demonstration that this theory's wrong has been made: Jews get circomsized for generations none of them's born circomsized... So tried to reproduce this type of evolution in a lab, generation after generation they were cutting rats' tails, expecting that at one point some would be born without a tail... they are still waiting.

Then Darwin arrived. Tu tu!
His theory's simple: individuals (not only humans, all beings) reproduce and at each reproduction some drifts happen (your DNA is not 50% from mum 50% from dad but 49,5% from mum, the same from dad and 1% from either that just changed a little bit). Then the fittest survives and can spread those very special genes that made him fitter than the others.
In the case of the rate of melanin, if two brothers go south with their wives, one of the brother's darker than the other, the lighter brother is x% more likely to died of skin cancer or subitt sunburn, if he does, he darker brother will have more children as he will get those with his wife and those with his brother's wife.
Mahematically you get this: if one darker individual has enough time before dying to have three kids and a lighter one can only have one, then after three generations you have 1x3x3x3=27 dark ones and 1x1x1x1=1white one. So you'd consider that what was three generations earlier a 50% pale population became a 96,4% dark population.

But it is not all. Sexual partners will seek the most successful individuals to mate with. You have imidiate consequences: if your boyfriend's rich you won't starve to death, and you have remote consequences incontiously, each partner's picking the gene pool (i.e. the individual) that as the most chances of survival. This is only logical you want your kids to survive, you know darker ones have more chances to survive, hence you go for the darkest individual you can find.
Possibly it is even trickier: if you assume that some individual are genetically more attracted by some kind of features in an individual (i.e. some type of genetic features) and if these features help to survive there going to be a feedback effect. For instance, if dad brings dark genes and mum I-like-dark people genes, your population is likely to get darker twice faster. This is called sexual selection and this is the second and most-forgotten branch of Darwin's theory.

That said I personally believe that Lamarck was not 100% wrong and that something (very slight genetical change) may happen in-utero.

Lets leave the classroom now and see the world's populations: people living close to the equator are consistantly darker. It is not because they are more tanned but because natural selection "picked" the fittest feature to survive in such a sunny environment: a high rate of melanin.

Send a couple of Englishmen in Mauritus, let them there for say 10,000 years and you'll get three possibilities: they all died out because of the sun and because the necessary genetical change didn't occure, or they became more tanned, or they've reinvented the umbrella (thus change their environment).

Many genetic features can be directly related to the environment:
- Small people where it is warmer, so the ratio mass/surface of skin (i.e. sweat, i.e. water consumtion).
- Some type of genetic disease that strenghten the imune system against malaria.
- High rate of lactose tolerance in cattle-growing peoples. etc.

What may confuse some is that often same environments bring similar genetic change eventhough there is no direct connection between the two. It is called convergent evolution, you can see it in humans:
- Large lungs and high rate of oxygene in the blood for mountain people
- Dark skins for people in sunny places
- high ration of fat-producing per calorie digestited for people with poor diets

But once more this type of convergent evolution doesn't mean they have anything in commun. Effectively the very dark South Indians are genetically more similar to North Indian than to Aborigenes with whom they only share their melanin rate. But saying they are connected makes as much sens as saying that a dolphin is genetically closer from a fish than from say a dog, because it looks more likke a dog. Nature just selected features that suited an common environment: the sea.

Some other features are disconected from the environment and thus from natural selection. Take the redhair for instance, we can quite safely assume that having red hair doesn't give you any advantage upon individual having blond one, but it is not a problem either, so none of them will disappear.

Originally posted by think Depends how pale you are. Most people arent "pale" as in pure White anyway. I just burn, so ive never been concerned about tanning. Besides if i did decide to get a tan, I would get skin cancer ive already got a mole that i gotta watch.

oh ok what i want to know is how did the light skinned people of ancient times the the Arabs, and the Caucasians not get sun burnt back then while they were in Africa?

NOTE TO EVERYONE:

With the Global warming approaching i think its best that everyone of all races where some time of sun block at all times ITS GONNA GET HOT! From what i hear....

Originally posted by xi_tujue whats the deal with asian people. For instance japanese women are verry light skinned but alot of men are quite darker. and those farmers in all of asia are quite dark

Well this is obvious; the amount of sunlight they're exposed to. That being said, I can't say Japanese men are any darker than the women, at least not that I have noticed among the Japanese I've met. As a curious side-note I could mention that one of the palest boys I've ever met was a an Asian (not sure from where) I played Magic: The Gathering with, his skin was pure porcelain.

Personally I must confess to some vanity when it comes to tanning. I really don't like being pale, and I think most people look healthier with some colour.

Edited by Reginmund - 27-Jan-2007 at 14:02

Getting sunburn is nearly impossible if you have black skin.

Popular misconception. The worst case of sunburn i've ever seen was on a black American who went skying in Austria in a t-shirt with no sunblock.
Incidently, in some countries, people with darker skin have a lower chance of surviving skin cancer, because they assume 'only white people can get it', when they notice the early symptoms, dismiss it untill its too late.

Everyone burns, just some quicker than others, and the same inevitably applies to skin cancer.

Originally posted by xi_tujue Originally posted by AfrikaJamaika Originally posted by xi_tujue whats the deal with asian people. For instance japanese women are verry light skinned but alot of men are quite darker. and those farmers in all of asia are quite dark Exactly! How are they able to get dark like that? Because i know some asians that cant..... I realy don't know (I would give you the awnser if I knew)

Originally posted by xi_tujue whats the deal with asian people. For instance japanese women are verry light skinned but alot of men are quite darker. and those farmers in all of asia are quite dark

Exactly! How are they able to get dark like that? Because i know some asians that cant.....


Edited by AfrikaJamaika - 26-Jan-2007 at 12:46

Originally posted by xi_tujue [QUOTE=Adalwolf]I'm not a redhead, but my dad is, and I don't tan well at all. I just get red for a few hours and then go back to my normal, 'white', color.

Your dad can't get a tan he only gets frekles. am I right?


Well, my dad has frekles, but I don't know if he gets them from going out in the the sun. He just gets red, like I do, after spending time in the sun.

I'm not a redhead, but my dad is, and I don't tan well at all. I just get red for a few hours and then go back to my normal, 'white', color. 

Originally posted by Reginmund Europeans can't tan their skin darker? Depends on what you mean by "dark" of course,

Yes your right but im talking about dark as shades of like caramel, brown, dark brown, and even black...Sorry i should have stated that earlier...

Yes, almost everyone can tan. I am merely pointing out that Africans and other people living in similar condition became black because of their adaptation to the vast of sunlight. Asians are brownish because we have a moderate climate. Europe, suffice to say, do not get a lot of sunlight but some Europeans are not completely white, especailly for folks in Med. sea.