The Clitoris

[Honir]

I'm wondering if anyone knows any research related to the purpose and speculated evolutionary history of the clitoris. Its mere existence seems to complicate the hypothesis that sexuality and sexual pleasure evolved only as an incentive for procreation. I remember reading in a feminist theory class that it might be an evolutionary spanadrel, a structural necessity of where to put all those nerve endings when there's so little genetic difference between males and females, but I have no clue how accepted that idea is.

[ginckgo]

sorry, couldn't resist.

I gather the clitoris develops from the same embryonic parts that in males produce the penis. So it's like male nipples, but a lot more fun.

[NoSoul]

The clitoris is homologous to the penis, and the labia minora are homologous to testicles. Developmentally, the embryo develops sort of a proto-clitoris & labia which eventually develop into either female genitals or male genitals. Really, the female genitalia "come first," in that any male develops more or less "through" first developing female genitalia on the path to male genitals.

I assume other animals with sexual dimorphism share similar physiology & morphology, but I don't know.


Edit: Even though it's ostensibly a thread about male sexuality, this thread

viewtopic.php?f=4&t=80421

below on this forum has a good deal of discussion on female sexuality including the clit, as I recall.


As to the OP point that the clitoris somehow poses a problem ultimately to evolutionary theory, poppycock. Again, the thread referenced above discusses this a bit, too. The spandrel idea is pretty good; but it seems pretty self-evident that if it's homologous to the penis, it's going to have some of the same, or similar, sensual properties. Evolution in general is really messy; if something "just happens" to develop that doesn't hinder successful passing-on of genes, even if it doesn't necessarily perfectly help it, then it can end up sticking around, if it doesn't require too much energy/resources.

[scib0rg]

I'm curious about this also, especially considering that the location of the clitoris means that orgasm with penetration is not as reliable as it is for men.
THERE'S your evidence against design.

[sprite]

I'm wondering if anyone knows any research related to the purpose and speculated evolutionary history of the clitoris. Its mere existence seems to complicate the hypothesis that sexuality and sexual pleasure evolved only as an incentive for procreation. I remember reading in a feminist theory class that it might be an evolutionary spanadrel, a structural necessity of where to put all those nerve endings when there's so little genetic difference between males and females, but I have no clue how accepted that idea is.

There is little actual research or agreement about the clitoris. Some consider it as the embryological homologue of the penis, so it and the female orgasm only exist because they have been selected for in the male.

The connection between the penis, sexual arousal and orgasm are relatively straightforward in the male as is the connection to fertility, passing on genes and procreation.
For females fertility, sexual anatomy, sexual arousal, sexual pleasure, and reproduction are a lot more complex.

There is this section on the evolution of the clitoris in 'Primate Sexuality' p265-267:
http://books.google.co.uk/books?id=r56o ... #PPA265,M1

Though I disagree with Elisabeth A. Lloyd's conclusions, her book 'The Case of the Female Orgasm' gives a good overview of theories about female orgasm which is obviously connected to the 'evolutionary purpose' of the clitoris.

Sexual arousal in females, at least when fertile/ovulating, can be understood to have been selected but the problem comes with orgasm which does not need to have been selected in females. The clitoris may be a homolgue of the penis but female sexual arousal is not merely a homolgue of male sexual arousal. Therefore the sensitive nerves etc in females would not be a 'spandrel'. That they have become concentrated in the clitoris may be the homologue, but, as Lloyd says, "[T]here could well have been selection maintaining the existence of the clitoris and its sensitivity in the various mammalian species, because it serves a role in motivation and in facilitating the female to engage in sexual intercourse."

I think the mistake in seeing the clitoris as a 'purely sexual pleasure' organ, not connected to procreation, is that even female sexual behaviour when not actually fertile is still connected to procreation in terms of reproductive fitness. Sarah Hrdy argues along these lines - that females who are motivated to mate with males when the females are not actually fertile can reduce the chances of infanticide by those males ie can improve their reproductive fitness.
And in terms of the clitoris specifically, she has argued that there is too much variation across species in the anatomy of the clitoris which also does not reflect the anatomy of the penis in the various species, so she argues it has its own independent selection.

As far as anatomy goes, the clitoris is mostly internal, dividing and running down either side of the vagina. See eg:
http://en.wikipedia.org/wiki/Vestibular_bulbs

I think the main problem is when female sexual anatomy is merely compared to that of the male. Developmental constraints and differential selection on the two sexes clearly affects how selection can act on each sex, but the fact that the sexes differ in reproductive anatomy, and fertility, and fitness behaviour means that these aspects in females need to be looked at in terms of selection acting on females specifically.

[Dick Terrapin]

The clitoris is homologous to the penis, and the labia minora are homologous to testicles.

I think you'll find that it's the ovaries that are equivalent to testicles/testes (scrotum not being the same thing).

[Monkeyboy]

Oh not this clitoris legend again!!

[Ale]

One may argue that as it is a source of increased pleasures in females (and if they called it glitoris that would save lots of treasure hunts conundrums ), this making rocket all sorts of biological etc etc reactions that make the female more receptive, and male more reactive, all this favours procreation and the effectiveness of penetration. To use agricultural terms, plant the seed deep in the ground.


In which species is it present and more developed?


Incidentally, if you could avoid calling it 'clit', would be like us females shorten it to 'pen'.

[scib0rg]

Oh not this clitoris legend again!!

Um... what do you find "ledgendary" about the clitoris, friend? Or is the above-mentioned clitoral orgins with which you object?

[Darwinsbulldog]

One may argue that as it is a source of increased pleasures in females (and if they called it glitoris that would save lots of treasure hunts conundrums ), this making rocket all sorts of biological etc etc reactions that make the female more receptive, and male more reactive, all this favours procreation and the effectiveness of penetration. To use agricultural terms, plant the seed deep in the ground.


In which species is it present and more developed?


Incidentally, if you could avoid calling it 'clit', would be like us females shorten it to 'pen'.

personally, I don't mind having a "pen" .

I think the penis is just some sort of mutated clitoris.