human mammary ponderings

[NavajoEverclear]

In a Devils Chaplain (a collection of Dawkins essays, but i dont recal if this proposition was his own our just something he was discussing) there was an idea put forth that differing physical features of races is due to sexual selection. This evidenced by the fact that two tall people of different races are found to have more genetic common compared to a tall and short person among the same race. I personally think its a case of sexual selection at the aid of natural selection. Those whose skin was best suited to an environment were healthier, more attractive, so sexually selected, thus accelerating natural selection.

 

Only mention this case for the purpose of realizing that sexual selection has had an actual and significant effect on the human species.

 

My observation~~~ it appears that the mammary glands of human females are much larger, and more aesthetically pleasing than the same glands manifested in other apes. They develop beyond what is neccisary for the function of producing milk.

 

My question~~~~~ Is the degree of development of female mammary glands a case of sexual/artistic selection, above and beyond what would have been selected by forces of nature, and practical needs?

[Mokele]

Probably. Large, firm breasts indicate youth (high potential fecundity), health, good genes, and adequate fat stores. Males attracted to these signals would have had higher fitness, and females would attempt to maximize these signals in attempts to gain superior-quality males.

[AzurePhoenix]

I was taught that as we shifted to bipedalism, the bulbous genetalia used by chimps in estrus would have been a hindrance to our new mode of walking, whihc resulted in the need for new forms of advertisment, AKA, robust breasts and buttocks.

[Martin]

...My question~~~~~ Is the degree of development of female mammary glands a case of sexual/artistic selection, above and beyond what would have been selected by forces of nature, and practical needs?

 

 

Some of the material in this thread

http://www.scienceforums.net/forums/showthread.php?t=11426

might be relevant.

 

not all of that thread is, but there is some discussion IIRC of how prominent breasts might have evolved.

 

the name of the thread is "why are men attracted to breasts?"

 

=====================

without going back over what was said there-----I recall a point somebody made (wasnt me and I cant remember who) about monkeys mounting from behind.

 

when our ancestors did it doggie style, males would have evolved some wiring in the brain that they get excited by the beauty of two nice round buttocks----the signal is that's good go for it and hump it. (one of the evolutionary roots of our aesthetic responses)

 

in those days females didnt need any genes to make swollen breasts and males didnt need any genes to program their brains to be attracted to swollen breasts, because as M was humping F he didnt even SEE her tits. it was not part of the picture---not a factor. so they could be visually insignificant.

 

then with bipedalism it worked out better to screw front-to-front in the newly invented MISSIONARY STYLE, but males were hardwired in the head to like a pair of nice plump buttocks. the CHEAPEST evolutionary solution was for her breasts to stay swollen more of the time. they looked like buttocks in some basic topography, at least the visual element of PAIRED MOUNDS

and there evolved a slight modification in the wiring of the male brain so he would get excited looking at her front.

 

we multicelled organisms have to give each other signals. quite a bit of evolution is just about giving signals.

 

there is a lot more to the breast thing.

and there was a lot more in that other thread.

but this BUTTOCK-TO-BREAST signal transfer going along with bipedalism is one thing I can remember

[Martin]

Navajo it just occurred to me to compliment you on the title of the thread

the style, or the tone and wording

 

some breasts are indeed ponderous

and it seems especially appropriate to PONDER them

 

and also fondle them, they are often about the right size for fondling as well as pondering.

 

the phrase MAMMARY PONDERINGS has a nice ring to it.

 

there is no question about it! evolutionary biology adds additional zest to reflecting about life.

[Cap'n Refsmmat]

I guess even a physics nerd has to think about naked women every once in a while...

[j_p]

My observation~~~ it appears that the mammary glands of human females are much larger' date=' and more aesthetically pleasing than the same glands manifested in other apes. They develop beyond what is neccisary for the function of producing milk.

[/quote']

 

The most obvious response is, aesthetically pleasing to whom, you or an ape? And which came first, the aesthetics or the mammaries?

 

The more important response is to question if you even realize you are attributing all human evolution to the male?

 

A human female's reproductive cycle is fundamentally different from an ape's. Humans evolved to live in a wider range of climates. A human female might naturally maintain a higher percentage of body fat than other primates. Human young remain dependant longer than that of other primates.

 

There are, in fact, lots of things that might have effected breast tissue development other than some male primate thinking, yeah, I want some of that.

[NavajoEverclear]

God martin, way to take the elegance out of anatomy in your first post, but thanks for the info and the compliment. Thanks ye all others too.

 

and JP i wusn trying to be sexist, its just i dont have any particular attractions to masculine features so i wouldn't know which ones to ponder upon. Also the mammaries obviously came first, i dont know what the crap you're trying to say . . . .

[Ironduke]

I think it was in People of the Lake that I read the human males the largest penises in proportion to body size among all apes, even gorillas.

 

Now we can say that women find large penises sexually attractive, and men find large breasts sexually attractive. Thus the genes are passed on and penis and breast size increases over the millienia.....

[Martin]

I think it was in People of the Lake that I read the human males the largest penises in proportion to body size among all apes' date=' even gorillas.

 

Now we can say that women find large penises sexually attractive, and men find large breasts sexually attractive. Thus the genes are passed on and penis and breast size increases over the millienia.....[/quote']

 

among all apes, I would guess that humans fall between chimps and gorillas, but this is really just a guess----I don't know.

 

in other words I think you may be mistaken in ranking humans as number one.

 

but you would be right to put the gorilla at the low end of the scale

 

this is where the ranking is according to the DONG-TO-BODY length ratio or volume ratio, either ratio would place the Gorilla with his weeny dong and large body well below the smaller-bodied but more studly Chimpanzee.

 

-----------------------------------------

 

One of the people that are knowledgeable about animals will, I hope, tell me if my guess is right. what I am offering here is a kind of conjecture to be tested.

My guess is based on the idea that an ape's FAMILY STRUCTURE should have something to do with it.

AFAIK Chimps live in promiscuous bands with several adult males sharing several adult females in a kind of free-love hippy commune type arrangement. When a female is in estrus she may decide to get it on with several of the dudes. In that situation a well-endowed male is likely to have more descendants---so there is a clear evolutionary advantage.

 

By contrast the Gorilla lives more like the old-fashioned Utah Mormon, where one adult male dwells in isolation with his several wives. Gorilla females are not, so far as I know, promiscuous, but are faithful to their husky patriarch. This may simply be lack of opportunity, assuming he is actively inhospitable towards other males.

 

In the Gorilla's situation the evolutionary advantage is more for biceps and an imposing stature, because he competes by shooing the other males away. In the Chimp case he can be a little guy with skinny biceps and still do just fine as long as he is OK in the balls and pecker department, has a nice smile, tells charming jokes, and so on.

 

As a wild guess, I would put humans in between Chimp and Gorilla on the basis of their family structure. Humans in the wild state (as observed, for example, in High Schools) seem content to live in large bands combining elements of both promiscuity and monogamy in their mating practices.

[Mokele]

The most obvious response is, aesthetically pleasing to whom, you or an ape? And which came first, the aesthetics or the mammaries?

 

The more important response is to question if you even realize you are attributing all human evolution to the male?

 

A human female's reproductive cycle is fundamentally different from an ape's. Humans evolved to live in a wider range of climates. A human female might naturally maintain a higher percentage of body fat than other primates. Human young remain dependant longer than that of other primates.

 

There are, in fact, lots of things that might have effected breast tissue development other than some male primate thinking, yeah, I want some of that.

 

It's hardly a sexist suggestion; sexual selection works both ways, hence why male birds are often so colorful (to please females).

 

Basically, all non-monotreme mammals have mamaries (monotremes like the platypus have milk glands that simply empty into pores in the skin, and the young lap it up) and fat stores. This was simply a case to relocating the fat stores in a more prominent location to advertise fitness. Males had a pre-existing preference that females exploited, and in turn the males found that they could use it as an index of valuable information about the female.

 

It's happened the other way around, too. Testosterone is an immuno-suppressor, so only fit males with strong immune systems and low parasite loads could afford to develop strong, 'masculine' secondary sexual characteristics, which the females could use to select the mate with the most beneficial genetic material. (Incidentally, female humans' preferences in male appearance shifts markedly towards more masculine men during ovulation, which is also the time when adultery is most likely).

 

Sexual selection is a powerful force in evolution, one that can drive species to such ridiculous extremes as the male peacock's tail, or even outright suicide in the case of the male redback spider.

 

among all apes, I would guess that humans fall between chimps and gorillas, but this is really just a guess----I don't know.

 

You're right, but about the wrong organ.

 

Male humans *do* have the largest dong among primates, both in terms of relative and absolute size. However, your logic is completely correct for testes size (and thus number of sperm produced per ejaculate, a vital thing when your sperm might be cometing with that of the previous lover). Gorillas have small nads due to lack of competition, chimps have big nads, and humans inbetween.

 

Mokele

[Martin]

thanks for clearing that up.

 

In case something relevant might turn up, I will gather some links regarding sexual characteristics and behavior of other animals (for the most part, these links do not directly relate to humans)

 

http://pharyngula.org/index/weblog/comments/penis_evolution/

 

http://pharyngula.org/index/weblog/comments/how_to_evolve_a_vulva/

 

http://pharyngula.org/index/weblog/comments/lobster_sex/

 

http://pharyngula.org/index/weblog/comments/spider_kama_sutra/

 

http://pharyngula.org/index/weblog/comments/tentacle_sex/

 

http://pharyngula.org/index/weblog/comments/fish_courtship_and_sex/

[Nevermore]

Whoops, should have read the question more thuroughly before answering. Can a mod change it?