# Hymen Evolution **URL:** \ **Category:** Factual Questions\ **Created:** [June 23, 2011, 1:32am UTC](https://boards.straightdope.com/t/hymen-evolution/586512 "2011-06-23T01:32:04Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Meatros](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Meatros](https://boards.straightdope.com/u/Meatros)\ **Post date:** [June 23, 2011, 1:32am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/1 "2011-06-23T01:32:04Z")
I have no idea why this thought popped into my head (especially while watching the film ‘the nature of existence’, or maybe I do…), but it’s here and gnawing at me. How did he hymen evolve? ---
**Author:** ![silenus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/silenus/32/166_2.png) [@silenus](https://boards.straightdope.com/u/silenus)\ **Post date:** [June 23, 2011, 1:46am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/2 "2011-06-23T01:46:38Z")
There are no “he hymens.” There are only “she hymens.” ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 23, 2011, 1:55am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/3 "2011-06-23T01:55:58Z")
It is a total seal inside the womb for the fetal child, and only sightly opened after being born. It may be a way to minimize infectious stuff from entering or may be needed in the womb for some development. ---
**Author:** ![friedo](https://avatars.discourse-cdn.com/v4/letter/f/8edcca/32.png) [@friedo](https://boards.straightdope.com/u/friedo)\ **Post date:** [June 23, 2011, 2:07am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/4 "2011-06-23T02:07:40Z")
> [@kanicbird](#): > > It is a total seal inside the womb for the fetal child, and only sightly opened after being born. It may be a way to minimize infectious stuff from entering or may be needed in the womb for some development. Uhh, what? ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [June 23, 2011, 2:09am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/5 "2011-06-23T02:09:42Z")
> [@friedo](#): > > Uhh, what? Consider. Source. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [June 23, 2011, 3:14am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/6 "2011-06-23T03:14:35Z")
The last time I saw anything on this was in an old [SD column](http://www.straightdope.com/columns/read/919/what-is-the-purpose-of-the-hymen), and the answer back then was “no one knows what hymens are for”. ---
**Author:** ![Captain\_Amazing](https://avatars.discourse-cdn.com/v4/letter/c/6de8d8/32.png) [@Captain\_Amazing](https://boards.straightdope.com/u/Captain_Amazing)\ **Post date:** [June 23, 2011, 6:11am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/7 "2011-06-23T06:11:44Z")
> [@kanicbird](#): > > It is a total seal inside the womb for the fetal child, and only sightly opened after being born. It may be a way to minimize infectious stuff from entering or may be needed in the womb for some development. The hymen is a membrane that covers the vaginal hole. As such, it’s pretty much destroyed when the woman has sex for the first time, and can’t therefore seal the womb for the fetal child, for obvious reasons. ---
**Author:** ![Quartz](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/quartz/32/267_2.png) [@Quartz](https://boards.straightdope.com/u/Quartz)\ **Post date:** [June 23, 2011, 6:56am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/8 "2011-06-23T06:56:49Z")
But it can seal the child’s womb, can’t it? ---
**Author:** ![Capitaine\_Zombie](https://avatars.discourse-cdn.com/v4/letter/c/e95f7d/32.png) [@Capitaine\_Zombie](https://boards.straightdope.com/u/Capitaine_Zombie)\ **Post date:** [June 23, 2011, 7:42am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/9 "2011-06-23T07:42:25Z")
> [@Der\_Trihs](#): > > The last time I saw anything on this was in an old [SD column](http://www.straightdope.com/columns/read/919/what-is-the-purpose-of-the-hymen), and the answer back then was “no one knows what hymens are for”. We’re all hymens after all. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [June 23, 2011, 8:30am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/10 "2011-06-23T08:30:53Z")
> [@Captain\_Amazing](#): > > The hymen is a membrane that covers the vaginal hole. As such, it’s pretty much destroyed when the woman has sex for the first time, and can’t therefore seal the womb for the fetal child, for obvious reasons. Actually, I looked up hymen on [Wikipedia](http://en.wikipedia.org/wiki/Hymen#Hymenal_resorption) and according to the article there it often survives sex. It’s birth that destroys it pretty much completely. > [@](#): > > In the normal course of life, the hymenal opening can also be enlarged by tampon use, pelvic examinations with a speculum, regular physical activity or sexual intercourse.[1] Once a girl reaches puberty, the hymen tends to become so elastic that it is not possible to determine whether a woman uses tampons or not by examining her hymen. In one survey, only 43% of women reported bleeding the first time they had intercourse, indicating that the hymens of a majority of women are sufficiently opened. > > _\_ > > After giving birth, the vaginal opening usually has nothing left but hymenal tags (carunculae myrtiformes) and is called “parous introitus”. Makes me wonder how often virginal women faked that old “blood on the wedding bed” test. ---
**Author:** ![naita](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/naita/32/5862_2.png) [@naita](https://boards.straightdope.com/u/naita)\ **Post date:** [June 23, 2011, 8:39am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/11 "2011-06-23T08:39:17Z")
> [@Captain\_Amazing](#): > > The hymen is a membrane that covers the vaginal hole. As such, it’s pretty much destroyed when the woman has sex for the first time, and can’t therefore seal the womb for the fetal child, for obvious reasons. I think the description is meant to indicate it seals the womb **of** the fetal child. (If it’s a girl, of course.) ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [June 23, 2011, 11:45am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/12 "2011-06-23T11:45:26Z")
> [@naita](#): > > I think the description is meant to indicate it seals the womb **of** the fetal child. (If it’s a girl, of course.) Except it doesn’t. My understanding is that cases in which the hymen forms a complete, hermetic seal are rare - and for that matter, problematic at menarche. ---
**Author:** ![Meatros](https://avatars.discourse-cdn.com/v4/letter/m/b4bc9f/32.png) [@Meatros](https://boards.straightdope.com/u/Meatros)\ **Post date:** [June 23, 2011, 11:52am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/13 "2011-06-23T11:52:50Z")
> [@silenus](#): > > There are no “he hymens.” There are only “she hymens.” Sorry, that should have been ‘the’ hymen. I was typing away at my iPad and didn’t notice. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 23, 2011, 12:13pm UTC](https://boards.straightdope.com/t/hymen-evolution/586512/14 "2011-06-23T12:13:01Z")
[QUOTE=Quarts] But it can seal the child’s womb, can’t it? [/QUOTE] The child’s womb is the one that is sealed, it would be sort of idiotic to say it’s the mother’s > [@Machine\_Elf](#): > > Except it doesn’t. My understanding is that cases in which the hymen forms a complete, hermetic seal are rare - and for that matter, problematic at menarche. Not inside the womb: > [@](#): > > At month 5, the vaginal canalization is complete and the fetal hymen is formed from the proliferation of the sinovaginal bulbs (where müllerian ducts meet the urogenital sinus), **and becomes perforate before or shortly after birth.** From [Hymen - Wikipedia](http://en.wikipedia.org/wiki/Hymen) ---
**Author:** ![Machine\_Elf](https://avatars.discourse-cdn.com/v4/letter/m/82dd89/32.png) [@Machine\_Elf](https://boards.straightdope.com/u/Machine_Elf)\ **Post date:** [June 23, 2011, 12:34pm UTC](https://boards.straightdope.com/t/hymen-evolution/586512/15 "2011-06-23T12:34:09Z")
> [@kanicbird](#): > > Not inside the womb: Interesting. Surely there are rare cases where it is perforate/absent long before birth. What happens in these cases? Infection? a plague of locusts? Nuclear armageddon? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 23, 2011, 3:56pm UTC](https://boards.straightdope.com/t/hymen-evolution/586512/16 "2011-06-23T15:56:20Z")
> [@Machine\_Elf](#): > > Interesting. Surely there are rare cases where it is perforate/absent long before birth. What happens in these cases? Infection? a plague of locusts? Nuclear armageddon? Probably nothing of note. Many people have little ‘abnormalities’ that have little effect on their health, but perhaps sealing the womb during fetal development has some advantages small as them may be. Perhaps even having the hymen after birth partly sealing the opening until it needs to be opened has a slight advantage as well. ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [June 23, 2011, 4:08pm UTC](https://boards.straightdope.com/t/hymen-evolution/586512/17 "2011-06-23T16:08:53Z")
> [@Machine\_Elf](#): > > Interesting. Surely there are rare cases where it is perforate/absent long before birth. What happens in these cases? Infection? a plague of locusts? Nuclear armageddon? Just a silly silly though on this and I don’t know if it’s even possible. Not that that has ever stopped me in the past. In the case of twins (and many species usually have multiples, so it would fit in with evolution a trait carried over to humans) maybe it’s possible that those cells from one fetus to be floating around the other fetus or maternal cells to be floating around with the fetus. The womb is a place designed to nurture and grow cells not genetically the same as it’s own, perhaps in a situation where the womb is not sealed these cells could attach and grow inside the womb of the developing fetus. Not that the fetus would have a baby, but those cells would be robbing the fetus of essential nutrients to grow. ---
**Author:** ![HeyHomie](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/heyhomie/32/207_2.png) [@HeyHomie](https://boards.straightdope.com/u/HeyHomie)\ **Post date:** [June 23, 2011, 5:50pm UTC](https://boards.straightdope.com/t/hymen-evolution/586512/18 "2011-06-23T17:50:46Z")
> [@Der\_Trihs](#): > > Makes me wonder how often virginal women faked that old “blood on the wedding bed” test. Back in those days women/teen girls didn’t use tampons, didn’t ride bicycles, and didn’t do a host of other things that women/teen girls do these days that can break a hymen. ---
**Author:** ![Toucanna](https://avatars.discourse-cdn.com/v4/letter/t/3bc359/32.png) [@Toucanna](https://boards.straightdope.com/u/Toucanna)\ **Post date:** [June 23, 2011, 7:35pm UTC](https://boards.straightdope.com/t/hymen-evolution/586512/19 "2011-06-23T19:35:50Z")
A passion for horse-back riding can go a long way towards ‘splainin’ to the new hubby why the Mrs. didn’t bleed on the wedding night. It’s _the_ classic excuse women in many cultures have used for generations !😃 ---
**Author:** ![TNWPsycho](https://avatars.discourse-cdn.com/v4/letter/t/47e85d/32.png) [@TNWPsycho](https://boards.straightdope.com/u/TNWPsycho)\ **Post date:** [June 24, 2011, 4:27am UTC](https://boards.straightdope.com/t/hymen-evolution/586512/20 "2011-06-24T04:27:31Z")
> [@Captain\_Amazing](#): > > The hymen is a membrane that covers the vaginal hole. As such, it’s pretty much destroyed when the woman has sex for the first time, and can’t therefore seal the womb for the fetal child, for obvious reasons. Slight hijack. When my girlfriend and I had sex for the first time she bled. But she had had previous partners and said even when she lost her virginity there was no blood. Did i break her hymen? [Next page](https://boards.straightdope.com/t/hymen-evolution/586512.md?page=2)