Skin colors and latitude

South indians may be darker then some tropical africans but higher latitude, also some places in central america are lower latitude then in
either Arabia or Some parts of india, but Central american indians are consideridably lighter skinned. Can that be explained by the forest cover in central america? I mean, arabia is mostly open desert. I mean,
most people in palestine or iraq are darker then Central americans for instance. Why are central americans so much lighter skinned despite the latitude?? And how are bengalis so dark skinned while their country latitude is no lower then central-northern mexico.

Have you ever been to Central America? It's not as bare as Asia Minor. It's hot, humid, and annoying!

is that why the people arent very dark? The tree cover?

That I am not sure about. However, I can tell you this. I grew up in Vietnam. I was very very dark. After living here for 3 years, I went back there to visit people and I was snow white compared to everybody else. That should tell you something about people's ability to adapt.

How about maybe that the selection only really works to make people living further north develop lighter skin, so that they can make the Vitamin D they need in the pale winter sunlight there? Maybe there's no real need to darken up if you're light skinned and move back to the tropics.

Anyone else watch the PBS show on the genetic tree of life for modern man a while back? It was The Journey of Man (click)The two-hour program aired on PBS Tuesday, January 21, 2003. It had some interesting information, but I think he needs to work on his timing a little, and he doesn't really get into the migrations into Europe as much as I expected. He talked about skin color on the show.He also talked about "Mungo Man" in Australia, and recent evaluation of evidence shows the age to be about 40,000 years ago instead of the 50k reported (although that matches the age of the oldest known artifacts in Australia).Enjoy

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we are limited in our ability to understand
by our ability to understand RebelAAmerican.Zen[Deist
{{{Buddha walks off laughing with joy}}}

och! o_O i loved that special. i was beginning to worry i had imagined it.

the book i'm reading (jared diamond - the third chimpanzee) suggests that it's more a matter of sexual selection that makes skin colors (and other traits) different. perhaps it started out by people getting lighter as they moved away from africa or something, but that's not what keeps it around. and it's not necessarily a racist idea. we all know that we imprint on people around us when we are young as to whom we will look for as a sex partner/spouse... animals do too. it's simply an expression of that. people biologically want to mate with someone who is genetically close (but not too close) to them. it ensures that mating will be successful. why are there interracial marriages and stuff in spite of this? you don't have to imprint on a family member, just anyone who was around before you turned six.just some theories the book puts forth. it seems plausible.
apparently darwin wrote a second (less popular) book on sexual selection after his natural selection book. at first he kept all sexual selection stuff out of his book because it (the idea of sexual selection) is so explosive...

Skin color really is just an evolutionary adaptation to the amount of heat and sun that a certain people are exposed to. For example, the first Causcasion people were basically what you would call a "white person" when they first evolved in Asia Minor. However, when they migrated in all directions across to Europe and Asia, they adapted to their surroundings, in some instances a huge change in skin color occured. A huge change like this would be for example Indians. When Caucasions arrived in India, the climate was SUBSTANTIALLY more humid and very few other places has as much sun exposure in the world. However, the people adapted over time, and through this adaptation, we now have the very dark skinned Indian people. (Note yes, Indian people ARE Caucasion). While Asians from North Asia tend to have significantly fair skin, South East Asians tend to have much darker skin, do to the larger amount of heat and sun exposure. Thats why you can be fairly light skinned, and then after living in a place like Arabia, eventually your family genes will change and the generations will become much darker skinned, or you can just get a tan! Haha, but thats basically Skin Color in a nutshell.
P.S. BTW im an Irish(white), Greek(Mediterannean), Malaysian(Asian) mixture and during the summer i can be as white as can be, and during the summer i can develope very dark skin, it all depends on your ethnicity and what climates you are exposed to.

but that dpoesn't account for so many people. there are vvery white people in the south pacific and aborigines are some of the darkest people around. there are many, many more that break that 'rule' and it simply doesn't match the genetics. it's really more likely that the removed time between the individual 'tribe' and the exit from africa is the highest factor. nothing else really works. your information is the old thought. there is a great deal of newer research. do some more studying before you make a decision.

I'm going to have to nitpick this one. Aside from some kind of mutation or interbreeding with the natives of Arabia, your "family genes" will not change. Your descendants may have more skin pigmentation, but that has nothing to do with genetics. Enviromental pressure (in this case, the almost constant exposure to the sunlight) makes the people adapt, on the individual basis, to live in such environment.In other words, if you and your descendents abstain from interbreeding with the native Arabians for 10 generations and then that generation decides to go back to North Asia, their skin color will eventually become light again.

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The Laminator

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I think I'd have to agree with Lam on that one factor because these kinds of "permanent" biological changes couldnt be brought about in such a short time as 10 generations.
I wonder though...would this change in the amount of pigmentation of the skin inevitably occur within this group over vast amounts of generations or is that something that is uncertain/impossible?

Only if it conferred a significant survival advantage.

Human populations are highly mobile, while evolution is a slow acting process. From these two facts we could predict that any geographically affected trait would correlate imperfectly with the geography.

yes and that would be a good and meaningful argument if all the exceptions to the lighter-higher/darker-middle association were recent migrants... but they simply aren't. there are light-skinned peoples who have been in the south pacific for thousands and thousands of years and the aborigines in australia have been traced to be the next oldest population from africa.it seems that the skin tone thing is more a genetic separation from africa or something.