how does an evolutionist explain different races? first of all it should be pointed out at the different races come from different environments which could be the cause, asians from asia, whites from europe, blacks from africa and so on. did the different environments have an effect on how each race adapted and evolved?
Originally posted by EcstremeVenom how does an evolutionist explain different races? first of all it should be pointed out at the different races come from different environments which could be the cause, asians from asia, whites from europe, blacks from africa and so on. did the different environments have an effect on how each race adapted and evolved?
You can probably think of human races as a little like dog breeds - one species, with some variations within that species.
Dog breeds are of course selected artificially. Human breeders choose certain traits and then selectively breed for those traits.
In humans, racial distinctions are possibly a result of different environmental factors. Certainly the pigment differences between africans and europeans seems to be useful adaptations to those environments. But that's not to say that these differences are caused by the environments. The truth is no one really knows since all we have to go by for early humans are fossils and they tend not to show up racial differences.
It should be noted that racial differences amongst humans are pretty small and trivial - notwithstanding the black/white skin thing ...
Originally posted by EcstremeVenom how does an evolutionist explain different races? first of all it should be pointed out at the different races come from different environments which could be the cause, asians from asia, whites from europe, blacks from africa and so on. did the different environments have an effect on how each race adapted and evolved?
Where did the very dark people in Australia come from?
Differences such as skin colour do result from the environment. The pigment melanin is found in all of us, but in higher amounts for example in native Africans. This confers protection against the extreme exposure to sunlight, and prevents conditions such as skin cancer from being more comon. On the other hand, dark skin is not as necessary in more temperate climates as the sunlight is not so intense. Pigmentation was lost in populations in europe most likely due to the reqirement for vitamin D syntheisis in the skin which requires sunlight. The lack of sun intensity, made it harder to make vitamin D with darker skin but also lowered the risk of skin cancer if darker skin was lost.
As for Aborigenes and asian people with darker skin, I can't find material to back this up at the moment, but as far as I know, they are decened from populations who lost their pigmentation and then regained it when they moved on to new areas where sunlight was high intensity.
Originally posted by Jake Ellison Differences such as skin colour do result from the environment. The pigment melanin is found in all of us, but in higher amounts for example in native Africans. This confers protection against the extreme exposure to sunlight, and prevents conditions such as skin cancer from being more comon. On the other hand, dark skin is not as necessary in more temp ntation and then regained it when they moved on to new areas where sunlight was high intensity.
My skin is dark and I am of African ancestry by way of removal to America via slave trade.
But I have never understood to what extent environment plays a part in skin color to the fullest extent.
Indonesia, India for example, are hot like equatorial Africa.
Where do you think the black Aborigonies of Australia came from?
Originally posted by EcstremeVenom how does an evolutionist explain different races? first of all it should be pointed out at the different races come from different environments which could be the cause, asians from asia, whites from europe, blacks from africa and so on. did the different environments have an effect on how each race adapted and evolved?
The answer is obvious with reference to characteristics such as skin colour. But some racial variation is likely accidental, like eye colour.
Originally posted by jaywill My skin is dark and I am of African ancestry by way of removal to America via slave trade.
But I have never understood to what extent environment plays a part in skin color to the fullest extent.
Indonesia, India for example, are [b]hot like equatorial Africa.
Where do you think the black Aborigonies of Australia came from?[/b]
Like I said, enviroment is important due to the balance between the dangers of overly intense sunlight and the need for sunlight to create vitamin D. Asian people, I think, are decended from populations who initally lost their pigment and then regained it. Remember, when I say 'lost' I don't mean that in the truest sence of the word because we all have melanin in our skin to greater or lesser degrees. As for Aborigonies, as far as I know the same thing happened but to a greater extent then Asians. 'The Ancestors Tale' is a good place to look to find information on this, but I havn't time to find it right now. Its not a text book so its not particuarly easy to find some references.
Originally posted by Pawnokeyhole The answer is obvious with reference to characteristics such as skin colour. But some racial variation is likely accidental, like eye colour.
Actually this is not necessarily the case. Once again darker eye pigmentation prevents damage to the retina by the sun. This is why albino people can suffer eye trouble. As for why lighter eye colours developed I'm not entirely sure, and prehaps it was accidental, but there may be reasons.
Don't forget that when Humans began moving around there would be a lot less of them than there are now.
If small groups became separated as they migrated out of Africa any gene variation present within the group (such as eye colour) would be a lot more pronounced in the groups descendants than in the human species as a whole where it could mix within a much larger gene pool.
It's likely that with things such as eye colour which don't have an effect on a persons chances of producing offspring, that in a larger gene pool the trait would be 'bred out' . Within a small gene pool the amount of variation is going to be less after a couple of generations so the trait ends up being a pronounced feature.
For example, this is one of the reasons that a large percentage of oriental people are lactose intolerant, whereas in europe and the U.S this percentage is much lower.
Originally posted by Feastboy Don't forget that when Humans began moving around there would be a lot less of them than there are now.
If small groups became separated as they migrated out of Africa any gene variation present within the group (such as eye colour) would be a lot more pronounced in the groups descendants than in the human species as a whole where it could mix within a m ...[text shortened]... eople are lactose intolerant, whereas in europe and the U.S this percentage is much lower.
Yeah that makes sence. Not sure about the lactose intolerant thing though. There are a number of types of lactose interance, and the prevalent type amoung groups such as orientals varies between onset around the age of 5 or around the age of 20. This is due to the fact that lactose is 'baby food' found in milk and so lactase isn't needed in adults. In groups such europeans, a mutation occured allowing them to retain lactase as adults. You find in groups that typically drink milk as adults they have lactase, while those that don't drink milk don't have adult lactase. For some evolutionary reason some groups took to drinking milk as adults and this lead to selection in favour of adults who could best metabolise it.
This type of lactose intolerase is different to types such as galacosemia which is from birth, and can have very severe effects.
Originally posted by EcstremeVenom how does an evolutionist explain different races? first of all it should be pointed out at the different races come from different environments which could be the cause, asians from asia, whites from europe, blacks from africa and so on. did the different environments have an effect on how each race adapted and evolved?
"Race" is not a biological term.
Now we can talk about specific traits; for example, the different eye shape of east Asians, I've read, helps protect their eyes against dust storms. Dark skin protects against the sun. Etc.
Originally posted by Jake Ellison Differences such as skin colour do result from the environment. The pigment melanin is found in all of us, but in higher amounts for example in native Africans. This confers protection against the extreme exposure to sunlight, and prevents conditions such as skin cancer from being more comon. On the other hand, dark skin is not as necessary in more temp ...[text shortened]... ntation and then regained it when they moved on to new areas where sunlight was high intensity.
The lack of sun intensity, made it harder to make vitamin D with darker skin but also lowered the risk of skin cancer if darker skin was lost.
Originally posted by Feastboy Don't forget that when Humans began moving around there would be a lot less of them than there are now.
If small groups became separated as they migrated out of Africa any gene variation present within the group (such as eye colour) would be a lot more pronounced in the groups descendants than in the human species as a whole where it could mix within a m ...[text shortened]... eople are lactose intolerant, whereas in europe and the U.S this percentage is much lower.
Europeans tend not to be lactose intolerant because they have survived the millenia by drinking milk.
27 Jan '08 05:20
the different races and evolution
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