How did all racial physical differences come about?

[Lekgolo555]

How did all the racial physical differences become what they are?

 

I mean how did blacks and south asians and aboriginese end up with dark skin? How did asians end up with slanted eyes?

[ecoli]

traits produced by random mutations and perhaps the bottleneck affect. Beneficial traits amplified by selective breeding.

 

Keep in mind factors like climate.

[Martin]

How did all the racial physical differences become what they are?

 

I mean how did blacks and south asians and aboriginese end up with dark skin? How did asians end up with slanted eyes?

 

pigmented skin has evolved several times in human history IIRC in several different parts of the world because it is really handy as protection against UV damage.

 

when you don't want pigment is when you aren't getting enough vitamin D.

 

some biology wonk please correct me if I am wrong.

 

=================

 

it is important to note what ecoli indicates-----you don't have to have a clear advantage for something to evolve, you just need a bottleneck like moving to a different continent, that splits off two populations from each other-----and then you can sometimes get merely RANDOM genetic drift

 

=================

 

One explanation of some east Asian and Inuit features I've seen is the effect of COLD.

 

In the cold, like where Eskimos live, it is good to have a fairly flat face and a nose that doesnt stick out so much because it might freeze off---you want fairly shallow features to minimize surface area, so there is less heat loss. It even helps reduce heat loss if you have shorter extremities (fingers/arms/legs) compared with torso. The compacter the better. So if a population evolved in Siberia and Mongolia, it might have a kind of chunky look---and then some of those people could have spread out and moved south.

 

Ecoli said pay attention to climate----this is a specific instance.

 

Another (more guesswork than anything else) would be think about what a big nose can do for you in the DESERT. Your nose is a moisture resevoir that moisturizes the air you breath in so that extreme dryness doesnt wreck your lungs. And then on the way out the nose captures and holds some of the lung-moisture, and recycles it into the next breath you inhale.

================

 

what i've said is just guesswork. It would be interesting to get some links to research articles about this---more solid information.

[ecoli]

pigmented skin has evolved several times in human history IIRC in several different parts of the world because it is really handy as protection against UV damage.

 

when you don't want pigment is when you aren't getting enough vitamin D.

 

some biology wonk please correct me if I am wrong.

 

exactly. So, in high heat, sunny places like Africa, they get plently of vitamin D, and their black skin protects them. Up in europe, they maximize vitamin D by having low levels of pigment, and the angle of insolation is lower, so less worry about UV.

[Lekgolo555]

Ok let me ask another question: Which race was first? Black, white or asian.

 

I do not think it is black because animals are albino when take away the fur right?

 

(Im not trying to be a racist nor am I trying to crack any jokes:-) )

 

What is the epicanthic fold in the eyes for? Do it protect against cold wind?

 

Does darker skin really give better protection? What about yellow skin, what does that do for you?

 

Do people who live in the hotter regions tend to be bigger? If so then how did the african pygmies come about, and what about the amazon natives? They tend to be small also.

 

Also the nordic people are tall but they live in cold climates.

[Sisyphus]

Ok let me ask another question: Which race was first? Black, white or asian.

 

I do not think it is black because animals are albino when take away the fur right?

 

I don't know much about this stuff, but I'm pretty sure it's not nearly as simple as "black, white, and asian," which is merely a traditional division and not necessarily reflecting genetic realities. For one thing, there's much more genetic variety among "blacks" than in all other "races" combined. A more scientifically rigorous division (if that's possible, which is somewhat doubtful) might consist of several races of "blacks" and one of "everyone else."

 

In answer to your question, however, I can only assume the first humans would be black, as they lived in east Africa. Skin pigments are not unique to humans, so your observation about "albino animals" is not really correct. In any case, any pigment at all would make humans not albino, as "white" people are not really closer to albino than black people, since both "races" produce skin pigments in the same way and for the same reasons.

 

(Im not trying to be a racist nor am I trying to crack any jokes:-) )

 

Disclaimer duly noted.

 

What is the epicanthic fold in the eyes for? Do it protect against cold wind?

 

No idea. Maybe. More likely it's just random.

 

Does darker skin really give better protection?

 

Yes.

 

What about yellow skin, what does that do for you?

 

I've never seen anyone with yellow skin, and I don't understand where that cultural idea comes from. They don't have yellow skin.

 

Do people who live in the hotter regions tend to be bigger? If so then how did the african pygmies come about, and what about the amazon natives? They tend to be small also.

 

 

Also the nordic people are tall but they live in cold climates.

 

Not so much big vs. small as stout vs. lanky. A tall, thin body has more surface area and is easier to keep cool. A more compact body retains heat better. Remember, though, that that is just a general tendency, and there are bound to be exceptions. Also, remember that diet has a big effect on height, which explains most regional differences. Oh, and that "tall nordic people" thing is a myth.

[AutomagSam]

I remember hearing how blacks pgiment had something to do with their body adapting to the sunlight, and the whole theory that wearing black is actually better for you. I remember reading somewhere it had something to do with black body radiation, if anyone could fill me in, I'd really like some clarification.

[Bluenoise]

"I do not think it is black because animals are albino when take away the fur right?"

 

Never seen a hairless cat? They tend to big a mix of splotches of different colour.

[Lekgolo555]

to sisyphus:

 

I am chinese, when I go under fluorescent lights my skins has a yellow hue

[YT2095]

I`ve seen this before also, it`s quite true

 

I think what has to be gotten around here is the literality of it all, there`s no such things a BLACK Man/Woman, or a Red Man or even White or Yellow.

 

it`s all shades and degrees.

[Sisyphus]

It's dependant on the ratio and amount of pheomelanin and eumelanin. Pheomelanin is reddish brown, and eumelanin is dark drown. Those are the only human skin pigments, and you won't see any natural skin color that's not some combination of those.

 

Good article:

 

http://en.wikipedia.org/wiki/Skin_pigment

[YT2095]

I agree, and Good Post too!

[JHAQ]

Random initial steps in speciation

[bombus]

Ok let me ask another question: Which race was first? Black, white or asian.

They may have all emerged at about the same time from the ubiquitous Homo erectus. This is the alternative to the 'out of Africa' theory. Although the most 'primative' physical design of human can still be seen in the Ainu of Japan, the Australian Aborigines and a group of people from the Urals (don't know they're name).

 

I do not think it is black because animals are albino when take away the fur right?

What!???

 

What is the epicanthic fold in the eyes for? Do it protect against cold wind?

That's one theory. It could just be a neotenic trait resulting from the other adaptations. Mongaloid people are probably the most neotenic humans - one could say the most advanced (physically).

 

Does darker skin really give better protection? What about yellow skin, what does that do for you?

Already been answered.

 

Do people who live in the hotter regions tend to be bigger? If so then how did the african pygmies come about, and what about the amazon natives? They tend to be small also.

Not really, but the bushmen of the Kalahari and the Zulus are relatively tall and slim. It may be due to heat loss adaptations, but it could be due to lots of things. Pygmies and Hottentots are forest floor dwellers, and presumably, being small was advantageous.

 

Also the nordic people are tall but they live in cold climates.

 

They may be taller than Inuits and other mongaloids but Laplanders may well be shorter than Danes. The classical Nordics might not be the original humans and may have arrived from, say, Germany relatively recently (or at least, tall genes did at a time when the environment was less of a selector). Also, there may be other things going on selecting for height (competition from more southerly neighbours - who knows?). Norway/Scandanavia is also quite different from Mongolia/Siberia remember.

[foodchain]

pigmented skin has evolved several times in human history IIRC in several different parts of the world because it is really handy as protection against UV damage.

 

when you don't want pigment is when you aren't getting enough vitamin D.

 

some biology wonk please correct me if I am wrong.

 

=================

 

it is important to note what ecoli indicates-----you don't have to have a clear advantage for something to evolve, you just need a bottleneck like moving to a different continent, that splits off two populations from each other-----and then you can sometimes get merely RANDOM genetic drift

 

=================

 

One explanation of some east Asian and Inuit features I've seen is the effect of COLD.

 

In the cold, like where Eskimos live, it is good to have a fairly flat face and a nose that doesnt stick out so much because it might freeze off---you want fairly shallow features to minimize surface area, so there is less heat loss. It even helps reduce heat loss if you have shorter extremities (fingers/arms/legs) compared with torso. The compacter the better. So if a population evolved in Siberia and Mongolia, it might have a kind of chunky look---and then some of those people could have spread out and moved south.

 

Ecoli said pay attention to climate----this is a specific instance.

 

Another (more guesswork than anything else) would be think about what a big nose can do for you in the DESERT. Your nose is a moisture resevoir that moisturizes the air you breath in so that extreme dryness doesnt wreck your lungs. And then on the way out the nose captures and holds some of the lung-moisture, and recycles it into the next breath you inhale.

================

 

what i've said is just guesswork. It would be interesting to get some links to research articles about this---more solid information.

 

I was surprised to learn that surface area has such an importance overall in regards to temperature regulation, this is also important I think in relation to organisms closer to the ground then those that can get some elevation away from it, even if its not the entire body. There is speculation that some of our "ancestors", which were giants, may have failed in Africa eventually because of size in relation to temperature regulation.

[Motree]

Black skinned people are the oldest human beings on the planet so asking how black skinned people became black is a silly question. There have been much scientific studies to back up what I am saying. Whites were created through albino's and imbreeding. Recently in the last 10-15 years DNA has also shown in the mtDNA that whites most likely got their features, skin color, eye color and hair color from the Neanderthal or big foot.

[Glider]

Not really, but the bushmen of the Kalahari and the Zulus are relatively tall and slim. It may be due to heat loss adaptations, but it could be due to lots of things. Pygmies and Hottentots are forest floor dwellers, and presumably, being small was advantageous.

The Zulu, Masai and Turkhana are tall and slim. The Kalahari bushmen have an average height of around 4' 10''.

[pulasthi]

It's all about survival of the fittest. Now we see what is fit for that particular condition. i hope you can understand what i say.

 

myblog : www.pulasthi.info

[carol]

"I do not think it is black because animals are albino when take away the fur right?"

 

Never seen a hairless cat? They tend to big a mix of splotches of different colour.

 

yeah, a dog of mine has lost some hair, and it revealed a dark brown skin

[lucaspa]

Ok let me ask another question: Which race was first? Black, white or asian.

 

1. "Race" as in the 3 races is a meaningless term. What you want to talk about with any species is populations. "Race" can't be pinned down because the features we associate with the 3 races actually overlap among several populations around the world: 2. Scientific American article on race http://www.sciam.com/article.cfm?chanID=sa006&colID=1&articleID=00055DC8-3BAA-1FA8-BBAA83414B7F0000

 

2. H. sapiens evolved in Africa. As such, they had dark skin. This is to protect folic acid from UV radiation. As humans moved into higher latitude with less sunlight and UV, skin becomes lighter as protection from UV for folic acid becomes less important and UV for conversion of cholesterol to vitamin D becomes more important. Skin pigmentation is a yin-yang for these two requirements: protect folic acid so you don't have neural tube birth defects and allow cholesterol cleavage to get vitamin D so you have strong bones:

 

1 G Kirchwager, Black and white: the biology of skin color. Discover 22: 32-33, Feb. 2001. Nina Jablonski and George Chaplin have first comprehensive theory of skin color. Need sweat glands to cool skin and brain; then need less hair for sweat glands ot work better. Then need dark skin to protect from sun on hairless skin. An hour of intense sunlight cuts folate (vitamin B) in half). This results in neural tube defects in embryogenesis. Folate also necessary for sperm production. Skin color correlated to sunlight: the weaker the UV light, the lighter the skin.

 

I do not think it is black because animals are albino when take away the fur right?

 

Wrong. Read above. Hominids lost their hair for better cooling -- probably at the H. habilis or H. erectus species.

 

Do people who live in the hotter regions tend to be bigger? If so then how did the african pygmies come about, and what about the amazon natives? They tend to be small also. Also the nordic people are tall but they live in cold climates

 

I don't know whether this has been researched or not. You could search PubMed to find out. Height also correlates to nutritional status. Over the last 100 years the average height and weight of all human populations has been increasing as nutritional status around the world has improved.

 

Black skinned people are the oldest human beings on the planet so asking how black skinned people became black is a silly question. There have been much scientific studies to back up what I am saying. Whites were created through albino's and imbreeding. Recently in the last 10-15 years DNA has also shown in the mtDNA that whites most likely got their features, skin color, eye color and hair color from the Neanderthal or big foot.

 

Sorry, but no. mtDNA shows that there are NO neandertal sequences in H. sapiens. Neandertals were a separate species of Homo. Big Foot, of course, is a hoax and doesn't exist..

 

Experiments with the Y-chromosome backs up the mtDNA studies:

 

2. R Kunzig, Not our Mom. Discover, Jan. 1998: 32-33. Summarizes the DNA data on Neanderthals.

3. M. Krings et al., "Neandertal DNA sequences and the origin of modern humans," Cell, 90:19*30, 1997. Primary article on Neanderthal DNA.

8. C Zimmer, "After you, Eve". Natural History 110: 32-35, March 2001. Discusses Y chromosome patterns. Y "Adam" lived 59,000 years ago while "Eve" lived 170,000 years ago.

9. A Gibbons, Modern men trace ancestry to African migrants. Science 292:1051-1052, May 11, 2001. Y chromosome of EVERY person in the study could be traced to forefathers who lived in Africa 35,000 to 89,000 years ago. "one self-described 'dedicated multiregionalist,' Vince Sarich of the University of California, Berkeley, admitted: 'I have undergone a conversion -- a sort of epiphany. There are no old Y chromosomes lineages. There are no old mtDNA lineages. Period. It was a total replacement.' " In another study, Peter Underhill and colleagues analyzed 218 markers in 1062 men from 21 populations.Primary paper is Y Ke, B Su, D Lu, L Chen, H Li, C Qi, S Marzuki, R Deka, P Underhill, C Xiao, M Shriver, J Lell, D Wallace, RS Wells, M Selestad, P Oefner, D Zhu, W Huang, R Chakraborty, Z Chen, L Jin, African Origin of modern humans in east Asia: a tale of 12,000 Y chromosomes. Science 292: 1151-1153, May 11, 2001.

[bombus]

The Zulu, Masai and Turkhana are tall and slim. The Kalahari bushmen have an average height of around 4' 10''.

 

I stand corrected. It's a long time since school!

[Wormwood]

Ok you guys said skin pigment was effected by the climate and amount of sunlight, which makes sense, except for the eskimos...Why do they have dark skin and the Europeans in the cold climate developed lighter skin?

[insane_alien]

Ok you guys said skin pigment was effected by the climate and amount of sunlight, which makes sense, except for the eskimos...Why do they have dark skin and the Europeans in the cold climate developed lighter skin?

 

same reason you can get a suntan while skiing.

[lucaspa]

Ok you guys said skin pigment was effected by the climate and amount of sunlight, which makes sense, except for the eskimos...Why do they have dark skin and the Europeans in the cold climate developed lighter skin?

 

1. Eskimos migrated into their present habitat fairly recently: <12,000 years ago.

 

2. They eat lots of whale and seal livers. A great source of vitamin D. So they are getting sufficient vitamin D in their diet.

[Glider]

I stand corrected. It's a long time since school!

No worries, I had an advantage. I was born there (makes it easier to remember). These are Turkana. That's me, bottom left at the front.