Secondary Sexual Characteristics: Natural Selection or Sexual Selection? (choice, evolution)

[Sunstone]

Do you think secondary sexual characteristics are the result of natural selection or sexual selection?

The secondary sexual characteristics are such things as body hair, developed breasts, high muscle definition (in males), and so forth that develop at puberty. How did they evolve? Were there natural selective pressures that accounted for their evolution. Pressures such as diseases, predators, weather, etc. Or, were the secondary sexual characteristics selected for through sexual selection. That is, did they evolve because potential mates found them attractive and chose to mate with those individuals who exhibited them?

For instance: Is the size and shape of female breasts the result of natural factors in the environment, or the result of males finding that size and shape of female breast attractive?

Again, is the muscle definition found in males the result of natural factors in the environment, or of females finding that definition attractive?

[RevOxley_501]

i would say most definately sexual---sexual as a result of natural experiences:

IE: a strong man kills a sabre tooth tiger, his muscles kept him alive, woman sees this, relates muscle definition to her own safety, reproduces with this man..

[James the Persian]

Is sexual selection not just a specific form of natural selection? I'm not sure that it's even possible to oppose them in the way the OP posits. If the question were, is it down to sexual selection or some other aspect of natural selection, that would make more sense, but I still think the question would be more or less unanswerable, or rather the answer would be, 'Yes, both'.

James

[Sunstone]

Originally Posted by JamesThePersian

Is sexual selection not just a specific form of natural selection? I'm not sure that it's even possible to oppose them in the way the OP posits. If the question were, is it down to sexual selection or some other aspect of natural selection, that would make more sense, but I still think the question would be more or less unanswerable, or rather the answer would be, 'Yes, both'.

James

But surely we can draw a distinction between selective pressures that are human preferences (such as mate selection) and selective pressures that are not human preferences (such as diseases)?

[Real Sorceror]

Whenever I am presented with multiple choice, I always answer "Yes".
These secondary characteristics are the result of both natural and sexual selection.

[Sunstone]

Originally Posted by Real Sorceror

These secondary characteristics are the result of both natural and sexual selection.

Could you elaborate on how they are a result of natural selection and how they are a result of sexual selection? Or, perhaps you are thinking that some of them are the result of natural selection and some of them are the result of sexual selection? I'm not at all sure what you are getting at here.

[Random]

I find the poll categories confusing. In sexual selection there is intent and choice involved, but not in natural selection..? How is it that Sunstone seems to be suggesting that the sexual preferences of either human sex could result in biological differences? All of this differs from my understanding of natural selection. I don't know. Could someone clarify?

[Seyorni]

Originally Posted by Godlike

I find the poll categories confusing. In sexual selection there is intent and choice involved, but not in natural selection..? How is it that Sunstone seems to be suggesting that the sexual preferences of either human sex could result in biological differences? All of this differs from my understanding of natural selection. I don't know. Could someone clarify?

In sexual selection there's certainly choice involved, but not necessarily conscious intent. An organism can be very selective without consciously realizing it.

Sexual selection is a powerful evolutionary force, and it frequently produces negative adaptations to environmental conditions. A peacock's tail, a moose's antlers, a human's breasts, &al produce slower or clumsier individuals yet often require considerable resources to produce. It's a trade-off, inasmuch as these individuals are more sexually successful despite their handicaps.
This is how evolution works, though. DNA rules. It's willing to sacrifice a few individuals to produce more copies of itself in the end.