Sunday, May 23, 2010

What's the Evolutionary Purpose of the Hymen?


One of the things that I want my life story to represent, now that I've left the ministry, is that it is okay to question.  Scratch that.  It's essential.  The ability to ask questions and seek answers is what has made our species great.

While there is much about religion that I respect and admire, one thing that breaks my heart is that so many are paralyzed in fear from asking important questions.  I've been there.  If you question, you're a heretic.  If you question, you're listening to the devil.  If you question, you have sin in your life.  Science is different.  There's nothing too taboo to ask.  Nothing is sacred.  You can even ask about interesting sex related questions.  I think that's wonderful.

So, on to the task that has pitiful little evidence one way or the other.  I'll just list out some thoughts that I informally gleaned from the web (O, I should say that this is not intended to be super scientific since I'm no expert.  I more want to be heuristic and get your mind thinking about what questions you might have on your own!)

General Reasons to Many Mammals

Humans aren't alone.  Here's an incomplete listing of mammals with hymens: llamas, guinea pigs, bush babies, manatees, moles, toothed whales, chimpanzees, elephants, rats, ruffed lemurs, seals, et al.

Humans are born with a completely enclosed vagina.  After birth, at varying time lengths of time, it opens up.  Interesting article by a pediatrician on the subject of dealing with daughters that don't open :http://www.drgreene.com/qa/fused-vagina .  Apparently this affects 1-10% of girls and can be a serious health concern (possibly death if left untreated)

Might it stop a casual first encounter and cause females to wait until they have better development and/or judgement to pick the best mate possible?  Maybe.

Might it slightly reduce (at least for a time) contaminants coming in or too much fluid going out?  Could be.  Could this be involved with fostering the right kind of yeast and bacteria to out compete the 'bad' guys?   A idyllic tropical oasis for the right kind of bacteria?  Maybe.

Could pain be important to women's sexuality?  Is it bonding to go through the pain of defloration?  Like my earlier vid post showed, cats, as an example, need vaginal trauma to ovulate.  Hmm, well, if it's so important why does the pain lessen with frequency of copulation?  If this is true, it seems to put a lot of evolutionary emphasis on the first time.  Is that justifiable?

Specific to Humans

Could it have been selected for in humans as 'proof' of virginity?  Possibly.  Might this have been important to human males to verify with slight certainty that they weren't about to be cuckolded?  There's a chance, but the whole thing can be so variable I feel like that's thin ice to argue on.



One of the reasons that there is so little certainty in this respect is that there is such a wide variety of hymens.  Some women never have them.  Others have to deal with a completely enclosed vagina and, of course, everything in between.  It's a complicated matter, but it's great to have the freedom to ask questions.

8 comments:

  1. Interesting article on surgical procedures that can be done for these various issues.. and how this can be incorrectly diagnosed.
    http://www.ourgyn.com/content/index.php?option=com_content&task=view&id=14&Itemid=66

    mr

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  2. Wow. Very interesting. It's good that people are educated about this stuff. Avoids misunderstandings, and hesitations to get help.

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  3. Considering the amount of variability; it is most likely that the hymen is simply a vestigial remnant of the development of the fetus.

    There are many aspects of physiology that are merely unintentional byproducts of other processes. 3 disparate examples:
    1) Nipples on men are a vestige that is not biologically detrimental, so it is not selected out...No selection pressure.
    2) Blindness in diabetics is not due to Nature selecting it for its evolutionalry advantage. Diabetic blindness is due to the side-effect of diabetes...Natural Selection has no/little control over it.
    3) Male pattern baldness... some races tend to have a higher frequency of such alopecia. Jury is still out. It could be sexually selected for; either to distinguish a senior for ranking purposes, or because it is attractive. There's also some talk of it exposing the scalp to the sun for more Vitamin D production.

    So there we have 3 different reasons why a human trait either develops is is purely unavoidable. The hymen is thus an 'accident'; an unavoidable part of fetal growth.

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  4. Sam, thanks so much for commenting! It's a fascinating subject, isn't it? I've posted before on a couple related topics. Here they are for your perusal and commenting: http://thesymbiont.blogspot.com/2010/06/human-evolution-proofs-in-picture-form.html
    http://thesymbiont.blogspot.com/2010/01/role-of-human-hair-in-evolution.html

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    Replies
    1. Hi Lee, I went to your 2 sites. Must say they're very comprehensive!
      ( http://thesymbiont.blogspot.com/2010/06/human-evolution-proofs-in-picture-form.html )
      Great deal of work, knowledge & wisdom you've put into your web site. I'm sure many people, as I do, appreciate them & learn a lot from your blogspot.
      Many thanks....You'll find me on www.Rationalskepticism.com , once my 12 month suspension runs out in December ;-)

      Delete
    2. That's awesome, Sam. I would love to see your site once it's up and running again!!

      Delete
  5. "Nothing is sacred."

    I wish it were so but a lot of smart, scientific minded people hold materialism up as undoubtedly true as a scientific fact when it is obviously philosophy.

    BTW, interesting path. I'll be checking out your blog more.

    Also someone like you would get a lot out of LSD. Psychedelics were designed/evolved for minds like yours. It's totally biological. Seek it.

    Peace

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  6. And everything is sacred!

    Thanks friend. I appreciate you commenting to let me know someone read this. :)

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