According to Jared Diamond, author of “Guns, Germs & Steel” (1997), the races of mankind were shaped more by sexual selection – who we choose to have sex with – than by natural selection – the forces of nature determining how we look. Darwin said the same.
Take skin colour, for example. It seems like a straightforward case of natural selection: light skin is favoured in places with a weak sun to prevent rickets, while dark skin is favoured in the tropics to prevent skin cancer.
That makes sense, but it is not quite that simple – for two reasons:
- Almost no one dies of skin cancer young enough to affect having children. So it does not affect natural selection.
- The amount of sunlight a place receives does not quite match up with skin colour. The general pattern holds but there are plenty of places where the two do not fit, like Tasmania, the Amazon or parts of Africa.
For things like eye colour and hair the match-up is even worse. Why do people in Europe, for example, have blue eyes but nowhere else? The conditions in Europe are not that strange.
Diamond says that physical attraction, what we like physically in a mate, messes things up. Nature matters but sex does too: To have children you must not only live long enough in good health, you must also be desirable to the opposite sex.
That is why women have large breasts, for example: not because babies need it, but because it turns men on and helps to create the babies in the first place.
But what determines what turns men on? Is it something they are born with? Diamond says no: it comes from who you grew up with. We know that from studies done on birds: if a bird is raised by a different race, it will tend to mate with that race even when given a chance to mate with its own race.
It is not just birds. Diamond notices the same thing among Chinese American women: those who grew up among whites tend to marry white even when given a fair chance to marry Chinese. Likewise, those who grew up in Chinese neighbourhoods tend to marry Chinese American husbands even when given a reasonable chance to marry white.
That tells us why most people prefer their own race, but it does not tell us how the races arose to begin with.
Partly it is from the forces of nature, but mostly it is from the founder effect: humans spread across the earth in little bands. When a band settled in a new land, the genes of that band would have a huge effect on those who came after for thousands of years. That is why blonde hair is native to Europe but also to Australia. It was not because of the sun or anything, but because a few people in the bands that settled those places turned out to have blonde hair.
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Interesting post. We can see examples of counterintuitive mating decisions all around us. For example, many years ago possession of a fancy carriage/automobile signified that the possessor had wealth and power, and thus it was a natural attractant. Nowadays, especially in many of our urban areas, a fancy automobile often means that the possessor is a short sighted nacissistic spendthrift, devoting most of his resources to the temporary possession of a depreciating asset, yet, in a Pavlovian sense, the automobile remains an attractant. Thus, perhaps our culture’s preservation of certain memes that once signified wealth, but no longer do so, means that we are selectively breeding certain self-destructive personality traits within our cultural fabric.
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The expensive automobile is still attractive to women because the men who own them still have a high chance of being wealthy. Power and wealth will never stop being attractive to women; it’s part of evolution that is still with us.
Though we may be thousands of year removed from the early days of our ancestors, are brains are not. Evolution is a very slow process. We might have mastered all kinds of technology, built cities, and gone to the moon. Still, our brains have not evolved much beyond the hunter-gatherer era thousand of years ago. That’s why we still engage in such short sighted behavior. Does the same tribal mindset apply to mating? It probably does; people tend to be mate with those who look similar to themselves, or to their family. Either that, or they tend to mate with those who are from their same culture. For example, in the states, Indian women rarely will marry a non-Indian man. Muslim women never marry non-muslims.
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“because the men who own them still have a high chance of being wealthy”
That’s just it. Most drivers of expensive automobiles, especially in Southern Cal where they’re ubiquitous, don’t own them. They possess them, ususally via a lease arrangement, and usually devoting a substantial portion of their disposable income to them. Often, the car payment will exceed rent for the scuzzy apartment.
In other words, possession of an expensive automobile in a very large number of instances, maybe most, does not correlate with a chance the possessor may be wealthy. In fact, very often it corresponds with a possessor who is a short sighted narcissistic spendthrift — which is a bad candidate for fatherhood.
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Well Blanc, tell that to all all the women that love a man with a nice car. Because that stuff apparently works, or else these guys wouldn’t bother. Peacocks use bright and beautiful plumage to attract a mate.
The female peacocks apparently choose their mates largely based on the size and shape of their tales. This way of choosing a mate is just one type of sexual selection: members of one sex mating in disproportionate numbers with members of the opposite sex that possess some “showy” feature. In the humans species “showy” features are often linked to signs of wealth-cars, clothes, house, etc. (weather those signs are real or not is a whole separate issue.)
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I recognize that it works. It is indeed a form of Peacocking, abeit one that occurs within Pavlov’s “paradoxical” phase, the area where the subject salivates for the stimulus in the absence of actual food. Consistent with Pavlov’s experiement, decisions based on the automobile are often contra to the interests of the decider.
This goes to Agabond’s post — that sexual selection, even for seemingly arbitrary reasons, can move a social group in an evolutionary fashion.
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Abagond:
Some researchers believe “white skin” (pale) in Northern Europe evolved recently due to dietary changes (Moving more from fish and game to wheat and barley which required more vitamin D outside of the diet (such as from the sun) …)
http://www.timesonline.co.uk/tol/news/science/article6814896.ece
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Cool. Interesting article. Thanks.
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The simulation to the various climates we and our possible offsprings may live or live contributes one of the greatest factors in sexual selection.Many “African Americans” live now in Detroit,Cicago and New York.Many of them for over 40 years,many of them are from from Bantu backgrounds,and most of their offsprings remain in these areas.the climate is to say the least extremely different than the one in Nigeria,Cameroon or Congo,and at the best odds(when no other races might mingle with them),they will gradually adapt to the enviroment,a process whic varies in time.In the beginning,they would appear some minor or “invisible” to say the least traits that would help the new or existing generation to best adapt and prosper in their new enviroments.Not all would obtain these features,some mails for instance may become taller than other,smarter or obtain a stronger immune system to say the least,and the exterior characteristics that support this.There are many factors to refer to all explicitly,but keep in mind that the whole make-up of a population may have a completely different evolution if there are at the first place different than them groups.In the case of Detroit,the population in the next 50 years would be overtly dark brown,if immigration from the underdeveloped african and south asian countries halts.As the years and centuries,would pass them by,their offsprings or they during their lives would obtain more “caucasian” or differnet than theirs features(maybe similar to the once the “native” american tribes have/had in that place).If immigration of dark populations keeps going or an intermarriage with non-dark populations takes place we are talking about different evolution paths and directions.Some species dont necessarily vanish from the face of earth because the rich and smart people are “nazis” and mongers,actually this is the exception.Ofcourse many species wouldnt feel that glad knowing of their declining or non-exist chances to mate,and we are stepping now in a differnet scientific field,psychology. By the way since 1997 genetics had walked a long walk.You should read some new books about sexual selection and genetics.
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It’s part Natural selection, part diet, part sexual selection and part mutations(not as in freakish, but as in a change or a mistake in a fetus’s DNA). Skin tone and hair type usually have to do with natural selection and location. Diet can effect body type. An example of this is how Asian foods are usually lower in calories, producing more petite people. Mutations can occur for no apparent reason. If the mutated trait doesn’t cause the animal to perish, it’s often passed down to descendents. Some mutations are benifical (like dark skin in hot enviroments) Some are fatal, some are neutral and do no harm to the animal. Blue and Green eyes are a mutation from standard brown eyes that just so happened to appear in Europe, they were deemed attractive and continued through sexual selection. Blonde hair is another example of a mutation continued through sexual selection. According to the theory of Evolution variation in all life was caused by mutations.
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“Diet can effect body type. An example of this is how Asian foods are usually lower in calories, producing more petite people.”
You mean, like egg rolls?
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That last part of the article actually makes a lot of sense to me. I am black and grew up around a lot of people who didn’t look like me, and out of the ones who did, one was my best friend, and the others generally called us “whitish”, “white-bred”, “oreos”, etc. My brother says that the way I talk reminds him of Gabrielle Union. I think the whole talking/acting white/black thing is silly anyway, but whatever. It was irritating to have a black guy try to hit on you, and then ask why you “talk so proper” or are “so white-bred”. So Idk. Maybe that kind of thing did have an effect in a way I have never really dissected. So even though my relationship with my parents is fine, that could make sense as to why I am drawn to men who look like the guys I grew up around, who were mostly white. But I am also attracted to quite a few Latin and Asian men though, and I didn’t grow up around them. It’s interesting food for thought though.
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These posts are very interesting. I suppose culture would also pose as a major factor. As I am aware that if one does not understand the nature of exotic traditional practices, it could inhibit sexual attraction, based on “fear of the unknown” so to speak 🙂
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That sounds a lot closer to Lamarckism than Evolution.
http://en.wikipedia.org/wiki/Lamarckism
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^ I don’t think so.
The tendency to have large breasts would have been inherited, not acquired during the individual’s lifetime. The only difference would be that the individuals with larger breasts would be able to attract more mates, or at least attract a fitter mate who can produce more offspring.
That would cause genetic drift towards the individuals that produce more offspring, one of the methods of evolution.
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@Jefe
Ah, I get it. When I was first reading the statement, it sounded at if it was meant to indicate causation. But upon reading your explanation, and then reading the statement again, I can see how it could be said without putting the chicken before the egg, as it were.
However, I still cannot see how this could be significant in an evolutionary sense.
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I think the point is . . .
We could divide evolution into 2 main categories, natural selection and sexual selection. Sexual selection selects for traits that do not seem to imply survival fittest for the species, but which are selected for other reasons, ie, sex or for securing mates.
It is one reason why some animals, particularly males, develop ornamental displays or markings which would seem to attract predators, but also attract more females.
Of course, this is a theory suggested as a way to explain evolution for traits not viewed as useful for survival. It might explain why traits such as blue eyes, which do not seem to confer any survival advantage, are selected for sex and thus passed onto the next generation.
If there is any genetic basis for, say, homosexuality, then it would be likely be due more to natural selection than to sexual selection (at a species level) — eg, more non-procreating aunts and uncles to help raise their sibling’s children (that might be triggered during times of high population growth or urbanization) increase survival fitness at a species level, even if not at an individual level.
Even cultural practices such as circumcision, which offer no evolutionary advantage, offer a social advantage in sexual selection. A male who has undergone such practice would in theory, gain more social and sexual access to females. However, there will be no evolutionary move to be born without intact genitalia as it would be necessary to distinguish those who have gained this social access from those who did not. So, there is no sexual selection for this trait.
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@ Jefe
Sexual selection: I have always thought this to be a rather dubious idea when applied to human sexuality—the whole beauty being in the eye of the beholder thing. Human attraction is not an simple imprinted instinct, it is a very complex and often contradictory affair. It can change and adapt depending on what we are exposed to or even what is fashionable that year.
Also, the trouble with trying to apply it as evolutionarily significant is that primary selection is not exclusionary to secondary selection. Men may partner with one woman (based on her looks), but then go on to secretly mate with several other women who do not fit his primary selective criteria at all. Therefore in reality it has no bearing on the extinction of certain genetic traits.
This statement smacks of Lamarckism again, which seems to crawls into evolutionary theory at every turn.
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^ depends what you believe.
I don’t really believe that those characteristics transferred to the next generation genetically are the ones acquired in that single generation. So, I don’t believe it smacks of Lamarckism. But that is what I believe.
Sexual selection includes the handicap principle. Many animals acquire characteristics, eg, ornaments, which do not serve any useful survival purpose other than attracting mates. Usually it is the males who carry these markers. They are costly to produce and make the individual more susceptible to predation. Do you ascribe that to
– natural selection (non-sexual)
– sexual selection
– Lamarckism
– not related to evolution (but explained by something else)
I do believe that there is a sexual selection component to evolution, but who knows, maybe one day we will know the truth and explain all of those characteristics as some survival need.
These are all just theories anyhow.
We can prove that selective breeding works, as mankind has done it for millenia. But even those changes are likely not permanent. When pigs, dogs, cats, cows, turn feral, they might not retain their bred characteristics. When coloured carp is allowed to breed naturally, they also lose their colourful markings. Plants probably will lose their characteristics, as those that mankind chose may not be the ones that nature think is important.
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Do you ascribe that to:
– natural selection: To a degree. I realize that it occurs of course, I just think that it often gets inadvertently mixed up with a lot of other theories.
– sexual selection: Depends on the definition. But, in any case, I think that you have to look at humans different than you look at parrots.
– Lamarckism: No, it seems highly illogical to me.
I can best explain my objections in this way. I don’t believe that evolutionary theory allows for some sort of intelligent element within the “blind chance” that says, “Hey, that giraffe obviously needs a longer neck so lets add a few more vertebrae to its kids.” My objection in that people almost always borrow creationist aspects to support their evolutionary ideas, but then continue to talk about them as if they are purely evolutionary in nature.
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Why?
Of course they are different animals, but I don’t see what makes humans special, or how that is inherently different from comparing moose antlers to peacock feathers.
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My rule for sexual selection is thus;
1. The man must be breathing.
2. He must be alive, breathing and being alive isn’t mutually exclusive. Just look at some politicians for example.
3. He must be gainfully employed!
4. He must fork over his pay cheque every two weeks.
5. He must purchase bon bons, purses clothes, and foot wear for me on a constant basis.
6. Last but certainly not least, he must be willing to be in a woman led relationship, no questions asked!
Anything else such as looks, build etc, is icing on the cake! Depending on my chronic headaches he may get lucky once in a while!
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Lol! Herneith. The perfectly man is Rich sand dead. Lol!
@ Jefe
Why? Because a man is infinitely more complex than a parrot.
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“Almost no one dies of skin cancer young enough to affect having children. So it does not affect natural selection.”
Seems logical at first, but it neglects sunburn, which is quite troublesome, I’d say that’s even “invalidating”, even more so without medication and help from others. I had sunburns on my legs when I was 7-8 and I couldn’t walk for a while, it was too painful, that was from a day at the beach. I think it may have increased my odds of cancer as well. 😦
Fair skinned people on Africa would have to be either just as furry as chimpanzees (some are even white), or produce sufficient clothing, or yet, have mostly not-so-diurnal habits, always on well shaded areas from something like 10am to 3-4pm, which would left them with a much smaller window of opportunity for hunting and gathering while there’s till enough light to see and be safe from predators.
And just as important or maybe more important, it neglects the effect of cancer on post-reproductive lifespan, and how it could affect the concentration of culture/wisdom on a tribe/group. If the elderly life more, they can transmit more knowledge and customs to the younger generations. That’s one of the hypothesis for the origin of the menopause, by the way, and if I’m not mistaken, Jared Diamond himself agrees with that theory (which seems to explain also menopause in whales). I’m surprised he wouldn’t see the analogy. The effect isn’t so much in individual natural selection, but some sort of kin selection.
“The amount of sunlight a place receives does not quite match up with skin colour. The general pattern holds but there are plenty of places where the two do not fit, like Tasmania, the Amazon or parts of Africa.”
And there are conceivable reasons for the exceptions, which are more commonly dark-skinned people where’s there’s not that much sunlight. First of all, if darker skin is the ancestral condition for these people, rather than having evolved in their current environments, then you’d need sufficient selective pressure favoring lighter skin on those areas, which isn’t sure to happen, or to have happened with enough intensity to already have “whitened” those people in this time-frame (that is, maybe some of those people are being slowly selected for paler skins, it’s hard to tell). Enough vitamin D can be obtained with the appropriate diet, which is at least what happens with the inuit peoples.
And a complication could be even the role of sexual selection, these aren’t either-or hypotheses. Could be that darker skin in the “wrong” places was/is being maintained even *against* pressures from natural selection (sort of like the peacock’s tail, which isn’t “good” for natural selection itself, would be selected against and disappear, if were not the females maintaining it), and that paler skins also were favoured by sexual selection where it happened to be adaptive (or nonadaptive, as long as they already have enough protections, like clothing and means for a lifestyle that allows them them to be protected when sun is at its peak). Sexual selection wouldn’t be necessarily or more likely universally innately for paler or darker skin (or even just locally/racially innately for its own racial shade), the preference could stem from psychological imprinting, from cultural factors like fads, status, and fashion, and even more bare-bones biology, like babies and young children being “programmed” to prefer the skin color they see on their parents, the parent of the opposite sex, or in most people around them. This flexibility would allow for sexual selection to sometimes maintain the current skin shade in some circumstances and to provoke some sort of runaway sexual selection towards a different shade, in different circumstances.
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Interesting article,
From vast experience in world travel (and not just the typical 2 week vacation, moreover, living in other Countries at a minimum of 1 to 10 years each I.e. Germany, Saudi, China, Philippines and Brazil) I have to admit it is the Sun which plays an important part [if not the single most part] but ‘not’ for the reasons you barely touched upon.
Nor is it true that ‘who we grew up with in our surroundings’ [sic] that compels us to pick a mate of similar ‘look’. Far from it.
In fact, the only thing that ‘determines’ our choice of partner is a series of events, in a very short time as well, of interpersonal exposure to 1 [or a few ‘similar’ individuals reminiscent of the ‘1’] that makes that ‘determination’ coupled with a close 2nd determining factor of what/who the involved ‘society’ one grows up in deals with the sun of the area and the good and bad attributes thereof ‘it’ provides socioeconomically.
The short of it, even since antiquity, the more an area has bright and sustained brilliant sunlight, causing the people to be darker, but only when one ‘labors’ [along with the unknown to myself why individuals that are removed from such territoty over 1,000s of years more likely than not stay ‘close’ to the color from the Country of origin] will make ‘partners’ seek those of ‘lighter’ skin color from the preconceived notion that lighter equates to s life of less labor!
The converse is also true for the lighter skinned Countries, regardleds of labor in less sun, free time equates with being able to get more ‘concentrated’ sun -time and become unlike the rest of the light skinned laboring society.
Simple proof is most Asian Countries that must labor in the sun sell many varied products to be whiter! Many i never heard of till living there (the opposite of which here in the U.S. sells the converse such as tanning lotion and sprays to tanning booths) such as “whitening” lotions, sprays, pills and right down to using umbrellas daily en mass to ‘try and stay white”
Further proof of this is bolstered by personal conversation with the general populous with constituents of China, Philippines, Brazil [although Brazilian seem to have less of a tendency] Japan, Philippines and Thailand from the level of the grade student to Presidents and Principle of University’s and the older generation of these individuals I had the pleasure to know.
Additionally, to show the depth of individuals from ‘sun-based’ Countries’ desiring and understand ing that being lighter is better for both men and particularly woman [as instructed by elders] the latter are willing to have a child out of wedlock, simply to have the ‘lighter gene’ introduced into the family line.
There is much more naturally, yet we can see from virtually All ‘sun based’ nations through historical context [even the mayan an aztec outside of the most known egypt] that those that dif not labor were described as lighter. A disturbing ‘fact’ for sure to equate such a simple thing of ones natural skin color with success of ease of labor, yet it seems to rain true!
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