So I get why people near the equator evolved darker skin then scandanavians, but why do asian, aboriginal australian, or other groups have a typical physical appearance that doesn’t seem to be the result of environmental pressures?
Please elaborate…what “typical physical appearance” are you asking about? I suspect that many traits you are thinking of actually are the result of environmental influences.
It doesn’t have to be environmental pressure. Not all traits are adaptative. When a population becomes isolated enough, genes can simply fixate on specific alleles just because those alleles are what’s left after stochastic shuffling.
Say a population starts off with a 33-33-33 spread of big-nosed, small-nosed, medium-nosed individuals. But over time, as people die (some without leaving offspring) and others reproduce, you may see the distribution shift to 50-25-25. As more people die and reproduce (for reasons completely independent of nose size), you might have frequencies of 70-29-1. The end result is a population that has a specific “look”.
Or say we have a population, and then a subset of that population decides to migrate and colonize another area. That subset of individuals will carry with them a subset of the alleles found in the originial population, but chances are the individual allele frequencies will differ between the two groups. So, even if the original population has a 33-33-33 frequency spread for the three alleles, there’s no reason to assume that the migrants will also carry these proportions. For no reason other than pure randomness, there may be more small-nosed individuals in the subset who decide to migrate. Which means that the new population is likely to fixate on the “small-nose” trait over time. And they’ll probably grow up sneering at the big-nosed freaks across the river.
If the OP is talking about the fact that dark-skinned equatorial peoples also typically have tightly curled hair and wide lips and noses, those traits are linked to dark skin. It’s thought that the exaggeration of lips and noses counteracts that dark skin makes facial features stand out less. The features of asian peoples and native americans by extension are presumably originally adaptations to arctic climates.
African lips are no more “exaggerated” than European lips are “understated”, Lumpy.
Sexual selection, combined with the Founder Effect ( what monstro posted about ) played a big role, most likely. If, say, pointy breasts are considered sexy by tribe A, and rounded breasts sexy by tribe B, that will affect which women attract men easier and produce children. Fast forward a few millenia and a lot of breeding later, and the original tribes have become what we call an ethnic group, and due to their population size sheer inertia will keep Ethnic group A mostly pointy, and Ethnic Group B mostly rounded - personal preferences don’t have the same effect in a population of millions that they do in a population of dozens.
The same applies to hair color, hair texture, eye color, nose sharpness, and so on.
Would you have been happier if he’d said “It’s thought that the understatedness of lips and noses counteracts that light skin makes facial features stand out more”? :rolleyes:
To be honest, I have no idea what the guy was trying to say. Maybe he’ll come back and translate for us.
It was almost certainly the other way around. Darker skin is more likely the original condition of the ancestors of all humans, and lighter skin tones evolved later. It appears that the lighter skin of Europeans and the lighter skin of East Asians is the result of different mutation events-- so lighter skin seems to have evolved at least twice, independently, since our ancestors left Africa about 60k years ago.
What “typical physical appearance” are you thinking of? Keep in mind that physical appearance can be a function of sexual selection, too. If women like guys with red hair, then red hair starts to become more common.
I don’t know how to say it any plainer. Africans, Australian aborigines and other black skinned peoples have wide noses and lips. Europeans and Asians do not. Since these groups are not directly related, the question becomes why that might have a connection with dark skin. The best guess anyone has put forward is that facial recognition is a strongly selective trait for humans, and that for dark-skinned peoples this led to larger facial features. Or if you absolutely insist, that for light-skinned peoples smaller lips and noses yield the optimum result.
Or are you saying that in a contrast-adjusted black and white photo, Africans look no different than Europeans? If that’s the case, your stance isn’t even worth Pitting.
No, they don’t.
Second, Caucasians don’t show the widest variation in all traits, just certain superficial ones–hair color and texture and eye color, as you point out, along with skin color, which varies from very light to almost black. When it comes to something like height, on the other hand, Caucasians lose out to Africans, whose average stature ranges from 4’8" for adult male pygmies to 5’10" for adult male Batutsis. Similarly, “other races show greater variation in nose configuration, distribution of body fat, and so on.”
IOW Africans don’t have all wide lips, and non African’s don’t all have narrow lips.
- Aborigines don’t have particularly wide noses, althouigh we might allow they are slightly broader * on average* than NE Europeans. Lip size and shape is no different to that of the average white Amercan. I don’t know what you are basing your idea of what an Aborigine looks like on, but it appears you have never seen one.
Yes, they do. Do you understand just how big Asia is, and just how diverse thepeople living there are. Would you like to wager large sums as to whether people from Southern India or Asutralia have thelarger noses or broader lips?
Of course they look different on average. That isn’t the same as saying that the difference lies in thicker lips or larger noses.
Do you in fact have any evidence for your claim that Africans have thicker lips and larger noses than Asians or Europeans? I won’t even ask for evidence for the same claim re Australians. That is obviosuly nonsense.
Thus proving that the ability to put the seat back down, a good memory for birthdates and anniversaries, and a willingness to see housework as foreplay are clearly not genetic.
OK, let’s put it to a vote: either the people arguing with me in this thread are being politically correct, or I"m an ignorant racist. If the latter, I’ll shut up and go away.
Let’s not, we don’t take votes on the facts around here.
Instead hows about you show us the evidence for your contentions? I have asked.
A false dichotomy. You may be ignorant, or you may be racist, or you may simply be the victim of confirmation bias and cultural stereotypes. There are any number of possible reasons. The best way to figure out which is for you to tell us why you think Aborigines have lips of a definitively different type to the average white Amercian. If you can locate the source of your misunderstanding then you can ascribe a cause to it.
That’s a false dichotomy. It’s possible to be ignorant and not a racist. What you posted earlier was, with all due respect, ignorance. You know, the thing we’re supposed to be fighting on this MB. Nothing wrong with that, as our society is filled with ignorant factoids about race.
I think **Blake **laid it out pretty well concerning the incorrect information you have on the subject. No need to make this personal, or play the racist card. Let’s just look at the facts and leave the subjective stuff alone.
This is an overstatement as has been already pointed out.
Yes there are blacks with “exaggerated” features (nose and lips). And yes there are non-blacks with “un-exaggerated” features. But the theory you’re putting forth about people with dark skin having to somehow compensate by having broader features doesn’t hold up when you look at the large number of people who don’t fit the stereotypical phenotypes. How do you account for them?
Many East Africans have dark skin, but rather narrow features. Seen any Ethiopians and Somalis lately? The same can be said for dark-skinned Asians in India, Pakistan, Bangladesh, and other places. There’s probably more people with dark skin that don’t fit the stereotype than those that do. Don’t have any numbers to back this up, though.
Light-skinned populations show a wide range of phenotypes too. Broad noses and lips accompanied with light skin is hardly a rarity, especially in Asia. Spend some time around Koreans, Thais, and Chinese and you too will see this.
This has nothing to do with PCness, by the way.
You know, I bet this could have as much to do with human culture as any inborn genetic preference. For an extreme example, suppose a group develops a cultural belief that people with large noses are brave, while people with small noses are weak (because bigger noses leave room for more courage, obviously). After so many generations, I bet this group will progress toward larger-than-average noses, because the big-nosed people make more respected and desirable mates, while the small-nosed people are more likely to become pariahs.
So I bet cultural beliefs can serve as a kind of amplifier for certain traits that would normally have no effect on reproductive success. Maybe humans are unique amongst animals because we have some ability to “select” our own traits.
<sigh> I woke up this morning knowing I’d have to respond to this thread.
Yesterday, for reasons unrelated to the board, I was exhausted, angry, and had a skin about as thin as an amoeba’s. What I didn’t have the energy and patience to say was this:
I simply don’t have the time and energy to write a friggin’ Anthropology term paper with citations to back up what began as a fairly brief simple comment. I did not originate the idea that there is a relationship between typical facial features and skin tone. It’s been around for a while. Look it up if you like and decide whether the original proponents have a case or not. I haven’t got the strength for a cite-duel.
I will take your bet, because the “brave” big-nosed people will be the ones sent out to battle marauding predators/hostile neighbors/dark elves and such, and will thus be vastly more likely to die an early (and painful) death prior to reproducing.