Racial variations within evolution theory?

Question

I am just curious: Are different races assumed to have been present in our evolutionary ancestors, such as in the neanderthals and more distant ancestors?

I've noticed that racial differences seem to be ignored in evolutionary discussions, and so I am left wondering where to look for information about how different races in our species, as well as in those of our ancestors, came to be?

I notice that neanderthals are widely portrayed as being white, while the homo erectus species is usually displayed having a very dark skin color. Were there black neanderthals and white homo erectuses?

I mean, seriously... There's all this info on our ancestors, yet if an alien was to take a peek at everything, it would probably think that the modern white man has more in common, visually, with a neanderthal than with a homo sapien East Asian or African...

I realize my question turned into a blizzard of thoughts, but just give me some input on anything that you can that relates. Thanks!

Answer 1

neandertals are probably represented as white because they lived in a more northerly area. modern man mostly evolved as black, because most evolution of the homo sapiens line was done in the "cradle of humanity", in Africa. Differentiation into different colors (with the different features such as eyes, hair etc that come with it) happened due to the environment where the people lived. There is data supporting this--that the white nose is long, because the air needed to be warmed in the nasal passages, while black noses are shorter because the air was warm, etc etc. Seeing as people with 100% Swedish blood and people who are 100% native Australian and all other combinations of people can interbreed, all modern humans are the same species. This means that man differentiated into different colors AFTER the last evolutionary plateau was reached. That is, first we evolved in Africa then spread out over the world and changed color/height (through natural selection over many many generations) according to environment later.
All the pre-homo sapiens sapiens would have been black, I think. So all the representations you see at museums and drawings in books might show different skin colors and "racial features" but a. it's just speculation and b. could be done to personalize that pre-human to the audience, rather than be accurate.
If you ask evolutionary biologists about race, I think the majority of them will say that race is a social construct, and the genetic variance between, say, the aforementioned Swede and Australian Aborigine is no greater than between Swede A and Swede B.

Answer 2

K is correct, at least in part, race is a social construct and is no longer used in mainstream discussions of evolution. There is actually more difference between Swede A and Swede B than between Swede A and and Australian Aborigine. The other information offered is also rather valid. Skin pigmentation is a response to sun exposure. Sunlight (or UV radiation) causes your body to produce Vitamin D, a necessary vitamin for proper bodily function. Vitamin D is a fat soluble vitamin and as such can build up to unhealthy levels. So people exposed to high levels of sunlight have darker skin so that they produce less Vit D from the amount of sun exposure and people in high northern latitudes who get less sun exposure have light skin to make as much vit D as they can from what little sun the get. An exception comes from eating fish which is high in Vit D. There were populations in the northern reaches of the British isles that had dark skin from fish heavy diets as do modern Inuit. Neanderthals living near the sea or rivers with diets heavy in fish could/would have had darker completions, perhaps like that of modern Italians or north Africans while those living in the plains or mountains would have needed lighter complections for manufacturing Vitamin D.

Answer 3

I could write a paper on this subject very easily, so I'll just stick to some basics. Darker skin blocks out most of the sun's rays, which destroys folic acid needed for the healthy birth of children, but it also keeps the body from making Vitamin D from sunlight. Without vitamin D a woman would get rickets & most likely die during child birth. Therefore in areas with a lot of sunlight a woman would suffer from too little folic acid if she had light skin. If her skin was dark in areas of low sunlight (northern climates) she'd suffer from rickets. Today this is not a problem because women can eat fruit in the winter or take vitamins to make up for vitamin defeciencies.
As a result of this women with light skin had a reproductive advantage in northern climates & women with dark skin had a reproductive advantage in southern climates. Some evidence indicates Neanderthal did contribute some genes to homosapiens in the ME that were spread throughout the rest of the World, but rarely do these genes appear in West, Central or South Africa. It is "possible" that Europeans got their very light skin, eyes & hair from a longer association with Neanderthal. However this will not be resolved until we finish the gene sequencing on the Neanderthal... target date in 2009. Do a google on Bruce T Lahn, U of Chicago if you wish to see the info on what many "suspect" are introgressed genes from Neanderthal to Homo Sapien. I could leave many links on this subject should you express an interest.
Edit:
I would like to know what part of this posting the person that gave me a thumbs down disagreed with?. I can back up every statement with links to scientific papers.

Answer 4

If you get a successful lineage of hominids or any other species that is very widespread, you will likely get races. You see the same thing in wolves for example. The northerly ones are larger and often white. Figuring out if a skeleton is a different race or a different species has to be very difficult in hominids. They no doubt did exist.

I am going to give the aliens enough credit that they would recognize the skin color to be superficial.

Answer 5

You're talking strictly about the percentage of activated melanin in the skin, not racial differences.
Racial differences in Homo Sapiens Sapiens mostly arise from subtly different underlying facial structures brought about by breeding in isolated populations. Not that the entire concept of race isn't 9/10's racist bull and 1/10 relatively recent (geologically speaking) events like what I mentioned earlier.
As far as things go, there is no evidence that any of the hominid species you mention had any particular skintone, when they're represented by an artist they are often given skintones found in the population of modern humans inhabiting the area. That approximates the amount of melanin in their skin that would have been activated by their exposure to the sun.

Answer 6

they're oftentimes depicted that way through fact Neanderthals lived frequently in Europe, and lots extra recently (in all threat as recently as 15,000 years in the past). Homo erectus became a number of million years in the past, and lived in East Africa (around Kenya). And bear in mind that utilising the word "races" could be somewhat extra linguistically troublesome than "skin shade". All human beings in the Genus Homo have an analogous ancestor, and skin shade is basically through melanin content in the exterior - darker in warmer areas to guard from sunburn and what no longer. wish this facilitates.

Answer 7

Every human in the world can have their ancestral roots traced back to a single African tribe over 80,000 years ago. Scientist use one of two methods to trace out lineage back that far. The first method they take the Y chromosome of a male (only males have a Y chromosome, its the one that makes us males) and break it down to the purest form of DNA. (Its really amazing to see) They then take this DNA and place it in a special machine that can read the 4 molecules of DNA. They are often referred to as the letters A C T and G. Its like a 4 letter alphabet that gives our cells the directions to build the proper proteins that make up or body. Over a long enough period of time mutations form in our DNA. These mutations are called genetic markers and scientist use them to evaluate our DNA.

Y chromosomes can only be passed down from male to male, and because the chromosomes don't break apart and mix with the other chromosomes during the fertilization process of conception they allow scientist to see the a very similar copy of our ancestors DNA; with the new mutations of course. They then traveled the world taking blood samples of people that have lived in remote areas untouched by many outsiders. These people's DNA provided them with the evidence they needed to form a very strong theory.

The Second method is very similar but instead they use women. Inside of each cell you have a mitocondria. Think of them as the cells power plants. They make the energy that the cell needs. The thing with mitocondria is that they have their very own DNA code that they use to reproduce themselves. The other interesting thing is that the mitocondria DNA can only be passed down from the mother. Which means every women in the world has a very similar copy of mitocondria DNA that the first women of the world had. Of course this DNA has mutations too. They call her the genetic Eve.

So through these methods they have traced human origins back to an African tribe that existed 80,000 years ago. Which leads me to your race question. If we are of African decent shouldn't we be black? No. The reason being evolution of course. (This next bit of information could be a little wrong. If someone in the answer community finds fault in it please e-mail me so that I may change it.) Our body produces Vitamin D naturally with the help of the sun. I believe it is the only vitamin our body produces. The people of Africa have dark skin because of the constant sun light that is present there. The process of evolution has caused their melanoma(skin pigmentations that are responsible for skin color) to be more active. Therefore making their skin darker and protect them from the sun.(Another interesting fact: White, Brown, and Black people have the same amount of melanoma.)

When the last ice age began about 80,000 years ago the oceans kind of dried up. On the East African coast (the place believed to be the home of our genetic eve) the ocean receded about 20 miles in a very short period of time. The African tribesmen were unable to live in their caves (yes there is evidence that they lived in caves) and go collect fish and other sea food and bring it back to the tribe before it rotted. It is believed that a small group from this tribe set out on an expedition to find a more habital place to live. So they wondered up the east African coast in search of that place. They went into the middle east and from there they branched out. Some heading north west into Europe and some heading east to Australia and Asia. The further north our ancestors moved the less sunlight they received. (Keep in mind this migration is taking thousands of years, not just a couple of weeks.) Then evolution steps up and starts gradually making our dark skinned ancestors lighter. That way their body is able to produce enough vitamin D to make healthy bones. A professor once told me that it take about 17,000 years to turn a black family white or vise versa. Thats alot of generations.

So did white people evolve from Neanderthals? The answer to that is no. There are still scientist that are trying to find evidence of a cross breed between the two species but so far the results have been either inconclusive or just no.

Answer 8

Most generalized discussions of evolution concern macroevolution- the rise more complex creatures from the simpler ones. Race is a part of micro evolution- adaptation to local conditions.

Answer 9

colour as only a limited effect on evolution ,when it do`s it is usually because of the`survival factor.`eg 98%of rabbits are brown1%black 1%white.under "normal conditions"that is the status quo.an ice age occurs the white rabbits escape detection more than the black /brown white rabbits %96..this is not evolution .it is natural selection

Answer 10

If it will do anything for you; Cromagnum Man sp? appeared to be lighter-skined - in the special I just saw. And they took out the rest of the tribes, they were more advanced i.e., fire and throwing spears etc.