What's the purpose of the hymen?

Cecil's Columns/Staff Reports
1

http://www.straightdope.com/classics/a3_226.html

I don’t know what it’s for either. But in regards to the college teacher’s theory, I don’t like it for the following reasons.

For the vast majority of human existence, meaning all the time before we started agriculture and settled down in one place, we functioned on the Hunter/Gatherer method of subsistence. While marriage and family groups do occur within H&G groups, it is common for family decent to be matrilineal. Because back in the day the only sure fire way to know a kid was yours was if it came out of you, thus women were given the honor of family decent. Patralinial decent only seems to come up in the last few thousand years, when civilization got rolling. Agriculture keeps humans in one place, because women have the babies they usually stay at home, it’s easier to guess which baby belongs to which man. Men are freer to roam, making them more visible and powerful in the public world.

Now it is safe to say that all human females do have hymens, excluding those with birth defects. For a feature like this to develop in all human females, through the described method, it would have to occur within an original, isolated society containing all humans, all in one place, long enough for all human females to display the trait. This seems virtually impossible since Hunter/Gatherer groups are migratory and never form overly hegemonic societies. We all know separate groups of humans rarely agree on anything.

It seems as soon as we were Homo Sapiens Sapiens, we left Africa and started populating the world. All humans, while looking a little different, do have all the same parts, meaning the hymen would have to develop before leaving Africa. Which is when society, agriculture and civilization started to show up in Central-Eastern Africa and the Arabian Peninsula. Of the Hunter/Gather groups that exist today, many are still matrilineal and their women do have hymens. As far as we know, these groups have never been anything but H&G.

So in a nutshell; everything the basic human is was developed in Africa, patrilinial decent (from men) didn’t start until agriculture and civilization, humans were Homo Sapiens Sapiens (creatures with hymens) long before agriculture and civilization ever got started. The theory of men seeking wives with hymens doesn’t hold up because it is based on a patrilinial society which did not exist until humans were more spread out, not a small group in Africa that shares all the same traits we enjoy today.

Does that make sense? I know there is a lot left out and my ramblings might be a little baseless. Maybe somebody with a little more documentation on the subject ans a little more talent for non-longwindedness can add to this?

And about the female orgasm… I once heard the contraction of mussels in the cervix forces semen into the uterus. Can anyone else back me up on this?

M

2

Mike, I think you’re sorta on track there. But personally, I think it’s just an evolutionary holdover like the gallbladder. And being female, I can tell you that the hymen isn’t that big of a deal, especially as a girl ages into adulthood, virgin or not. It’s overhyped for the most part. This site gives an interesting bit of insight (Googled). Totally not safe for work or ninnies.

As far as the cervical contractions, you are totally on the money. Some enterprising researchers actually managed to install some cameras on very willing volunteers and captured the cervix’s head dipping down and up repeatedly during orgasm. It most certainly does serve a purpose. I saw the videos on a show on Discovery or some similar channel a few years ago. Incredibly fascinating stuff and proves how little the scientific community really understands female anatomy and sexuality.

3

Chix got mussels in their cervix?

Hmm, that would explain…naaah, too easy…

4

The notion that early human societies were matrilineal has become common, and has been put forth strongly for several decades by feminists, who lean heavily on the theories of Marija Gimbutas, the archeologist who invented the theory that early human societies were rather utopian, peaceful, and goddess-worshiping. Her books on this notion of a “gynocentric” culture, worshipping “The Great Goddess”, as the central theme of stone age culture became very popular, and Jean Auel’s novels certainly helped to spread the idea and make it seem like fact. But the truth of the matter is that we don’t really know. It’s a theory based on some very thin evidence and some very questionable assumptions; it might be true, but it is certainly a long way from being proven, or even accepted among professionals. Many prominent archaeologists were (and are) extremely skeptical of Gimbutas’ conclusions, the popularity of Ms. Auel’s novels notwithstanding.

The whole idea is based fundamentally on the discovery of many small, carved figurines of nude women, usually faceless, from the last Ice Age in central and eastern Europe. Gimbutas speculated that these were religious articles, and theorized an entire gynocentric, goddess-worshipping culture out of them. Other writers (particularly the feminist artists/poets Monica Sjoo and Barbara Mor) took the “Great Goddess” theory and generalized and extrapolated it into very popular books describing (as fact, not theory) details about how early humans lived in matriarchal cultures of peaceful equality, worshipping the female form and the Great Mother Goddess. But among archaeologists, the theory is far from widely accepted, and many other speculations have been put forth about the meaning of the so-called “Venus figurines” from Ice Age Europe (including the idea that the figurines could have been given as payment for women, which a man from a different tribe would give to the father of his “bride”). None of these theories is proven to be true, and they’re all very speculative, and undoubtedly colored by the cultural preconceptions and prejudices of those who propose them. But the chain of assumptions leading to a peaceful matrilineal culture for Stone Age man is extremely dubious. The truth is, very little is known about cultural gender roles in Paleolithic and Neolithic times.

But even assuming that heritage is traced via matrilineal descent, it does not necessarily follow that this was an “honor”, nor that a matrilineal society would automatically be also matriarchal: descent can be traced through the female line, while power resides in the male line.

I’m not suggesting that the college teacher’s theory of how the hymen was naturally selected for is correct; to me it seems quite unlikely. But the proposed argument against it presumes the existence of a matrilineal culture that is far from proven, so it’s really just as speculative. Ultimately, the “purpose” of the hymen may be unknowable, simply because the word “purpose” may be completely inapplicable, presupposing as it does an intelligence making conscious, intentional decisions. In terms of biological development, there’s no real evidence that such is the case.

Some references:

The Civilization Of The Goddess (Marija Gimbutas)

The Language Of The Goddess (Marija Gimbutas)

The Great Cosmic Mother (Monica Sjoo and Barbara Mor)

The Prehistory Of Sex (Timothy Taylor)

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A century or so, in fact. Matilda Joslyn Gage, for example, was a big believer.

6

It’s almost always a mistake to bring sociobiology into discussions regarding human evolution of anatomical features, because a) the former field is generally highly speculative, and b) most anatomical artifacts long predate modern (in the Homo sapiens sense of the world) social customs and behaviors. In the case of the hymen, a large number of non-primate mammals have hymens; such commonality among diverse species rules out that the hymen has some specific evolutionary purpose for human beings. Since the humen only prevents intercourse in rare conditions and otherwise doesn’t pose a physiological hazard, there’s really no selective pressure against hymens; virtually all women with or without hymens have children or not, regardless.

And it is not “safe to say that virtually all women have hymens”, at least in the traditional sense of a so-called maidenhead. There are population groups in which the hymen is (presumably by genetic drift) deprecated to the point of not existing, and many physically active women partially or completely seperate they tissue forming the hymen long before they become sexually active.

Stranger

7

It was hard to pass up such low hanging fruit, myself. To grab at it would be Shellfish of me, I thought.

8

The hymen apparently does serve a purpose in keeping amniotic fluid out of the vagina during fetal development. Its continued existence after birth is probably one of the numerous side effects of the neotenous evolutionary changes in humans. Some of these changes (i.e. larger brain due to extension of fetal growth rate) are advantageous, while others (i.e. early fetal suppression of body hair growth continued even after birth) are probably not evolutionarily significant, but since the relevant gene mutations were to “control” genes rather than to brain/hair-growth-specific genes, a lot of unrelated things are along for the ride, so to speak.

9

I have my doubts about this. After all, you don’t have a mouth hymen, do you?

My suggestion: Stop trying to find a “purpose” for anatomy. It didn’t develope because it had a purpose, and it’s pretty difficult sometimes to divine why the mutation managed to hang on.

10

No it doesn’t, and even if it did, of what possible benefit would that be? Amniotic fluid gets into every other nook, cranny, and crevice in the fetus without detrimental effects. And as previously mentioned, the hymen exists in a wide variety of placental mammals, not just humans or even primates.

Stranger

11

well, IIRC, we both pee into and drink our amniotic fluid in utero, so there

12

From the point of view of evolutionary biology, you have to look at which creatures have a characteristic in common before you can start saying when, how and why something developed and sticks around. Hymens are found in many different types of placental mammals (I don’t know about marsupials), not just humans or primates, but many families, ungulates, carnivores, whales, rodents, etcetera, so the rational for the existence of hymens must be looked at from an overall mammalian perspective, not a strictly anthropological one. An explanation involving human societal pressures may emphasize something that was already there, but does not adequately explain how it came to be in the first place.

There are a few explanations that I have heard that could be valid under this evolutionary consideration, but the most likely in my mind considers that the vagina is a hole into the body and there are several bacteria and other infectious agents that would love to use that hole to penetrate the body and set up house. While intact, the hymen keeps the bad guys out. During puberty and adolescence, the hymen becomes softer and more fragile, indicating that its original need is reducing. It is not giving up its original job until necessary, but in the evolutionary scheme of things, reproduction is more important than keeping one individual safer from infection. Besides, the hymen is just one extra layer of protection; an adult vagina is a pretty hostile environment for microbes.

13

The gallbladder is an active part of our digestive system. It produces bile and enzymes that are part of the breakdown of fats. Perhaps you meant the appendix. The appendix is active in many plant eaters, but in carnivores and omnivores, like us, it is usually just sitting there.

14

I agree, Nutster. It’s like that protective film covering many products when you buy them. Sure, it has to be removed eventually, but in the meanwhile, it provides a little extra protection.

15

We watched that in a Middle School science class. She got permission from our parents before hand. Boy were we enlightened :eek:

16

Not really, for a couple reasons.

  1. Hymens aren’t like the plastic seal on a yogurt carton; they’re more like what you’d get after you attacked it with a fork for a couple minutes. They are normally quite fluid-permeable and pose no barrier at all to bacterial movement.

  2. This doesn’t really matter as much as you might think, since the vagina isn’t actually a hole. It is a potential space that when not being actively penetrated does not allow access to the interior. When was the last time you accidentally got shower water up your asshole? It’s kind of the same thing with a vagina: it’s closed until it’s opened, and then it closes again. Generally speaking, infectious agents don’t tend get in there unless someone puts them there. When that happens, the vagina’s main defense is its relatively acidic pH, which most types of harmful microorganisms do not thrive in.

The hymen doesn’t need to have a purpose. Like the webbing between your fingers and toes, it’s an artifact of embryonic development whose presence incurs neither biological advantage or disadvantage. With no selective pressure against this trait, there’s no reason for it to disappear.

PS. Also, the cervical opening diameter does not increase during sex. If it did, you’d know it, because that shit hurts like nothing else. In nulliparous women, it’s barely a pinhole and sperms pretty much have to sneak by single-file.

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Nice  

Bus Shelter

18

(Bolding mine) No it doesn’t. The bile is produced by the liver and stored in the gall bladder.

19

The cervix opens and closes, not during sex, but during the monthly cycle. It opens about 1 cm just before ovulation, when a woman is most fertile, and again at menstruation to allow passage of menstrual fluid.

The cervix of a woman who has had a vaginal delivery is often open a few millimeters all the time. This is why the insertion of an IUD is easier on a woman who’s had babies. They have safe medications now that they can give to help dilate the cervix if it’s too closed to get through, but once upon a time, IUDs were for mothers only.

20

I’ve found more than one adult vagina a pretty hostile environment for more than just microbes.

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