Originally posted by NEGROPOLIS
So if a group of people lived away from sunlight (like in a cave) and had no food source for vitamin D for generations then they would eventually turn
Better to say that without any pressure to maintain melanin in the skin, mutatins would accumulate and wipe out the ability to make melanin, and
result in albinos.
I read somewhere that neanderthals (cave people) were found only in Europe.
Neanderthals made use of caves, but didn't live in them, definitly not the to degree that they'd be affected by this sort of thing. Neanderthals
existed in spain, the ukraine, and israel, and its probable that thats not the limits themselves, but just close to it.
I'm just curious to know how the races of the world began.
Skin colour is caused by melanin concentration. White people and black people have different concentrations of this pigment, melanin. Interestingly,
both white people and black people have the same number of melanocytes, cells in the skin that produce melanin.
With an increased concentration of melanin, there is less sunlight/radiation passing through the surface of the skin and into the tissues beneath it.
This is "good" when there is intense and direct sunlight, as in the equatorial regions. This is bad when in regions where sunlight is indirect and
the sky is very cloudly, like the more temperate regions. Thus in tropical/equatorial regions, a population of people will have selection pressure to
become darker and in sub-polar forests or at dim cloudy regions, the population will have selection pressure to develop lighter skin (because sunlight
is needed to manufacture vitamin-d).
This is why, for example, the people in the south of india are so much darker, on average, than the people in the north of india. And this is why
blacks in africa and aboriginies in australia have similar skin tones on the one hand, and fins and eskimos and koreans have similar skin tones on the
So it doesn't have to do with creating to very different races and then having various mixes of them to produce other 'races'. You start with a
naturally variable population, which, in my opinion, in the begining probably was very dark skinned, and you move them into different environments,
and you will get the variation that we see today. Keeping in mind that, along with this process, there is
admixture and movemetn between and
with-in populations, so you get a really wide variety of characteristics.
As far as characteristics not related to melanin concentration, they'd each have their own histories. Neanderthals were stocky and 'barrel
chested'. So, apparently, are eskimos/inuits. This is thought to be because having stumpier and shorter proportions is advantageous in cold windy
regions, because you hold in body heat longer. Whereas people in tropical climates, irrespective of being closely related to one antoher, tend to
have lanky bodies and longer limb proportions and are more gracile in build, probably because this is an advantage in a warm climate to prevent over
Is there any way that black people could have evolved from whites?
White people produce melanin, so definitly, you could have conditions where there is selective pressure to increase the concentration of melanin in
the population, and thus have darker people.
Or you could start off with very dark people and get all the rest, or start at some middle point and spread out in both directions.
I'd expect that actual albinos have little to do with this overall process.
Interesting, Charles Darwin thought about these sorts of things too. He figured that some stuff was just not important enough to make a dramatic
difference in terms of survival. After all, white people don't die of sunburn in the tropics and blacks don't fall apart in england because of lack
He figured that the different characteristic 'racial' features were, perhaps if started by natural selection, were maintained and reinforced and
exxagerated by sexual selection. That is, consider that a peacock has a crazy colourful tail. It serves no advantage, except that peahens really dig
multicolored tails. So that trait gets maintained and even exagerated.
So Darwin figured that amoung humans, each group has its own idea of whats attractive, and that that has lead to the differences between peoples. So
europeans, for whatever the reason, started to favour light skin and fair hair, thus anyone with very light skin and very fair hair or very blue eyes
was highly desirous as a mate. Or in africa it'd be the opposite, pale people with no colour in their hair would be regarded as freaks, and who'd
want to mate with that? Or in the far east perhaps very straight hair was much favoured, adn any one with curly hair was rejected, or anyone with red
hair was rejected, etc etc.
As some examples (all in the name of science mind you)
you can see that this woman
is considered beautiful in one culture put perhaps not beautiful in the culture that considers this woman beautiful
or that perhaps neither society woudl consider this woman beautiful
who's society would probably want nothing to do with this woman
but perhaps that society would also find this woman acceptable
And so on and so on. Heck, here
you can see a country by country break down.
To me this makes some sense. Though, consider what was 'desirous' in a mate 100 years ago in the west and compare that to now and you can see that
these ideas of beauty are pretty fickle, so I don't know if they can really be in effect long enogh to have an evolutionary effect.
These type of questions have been dominating my mind lately and they may enter your mind from time to time as well and since two heads (or four) are
better than one; maybe we can figure 'em out together.
[edit on 2-2-2006 by Nygdan]