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Extinction of males?

  1. Jan 8, 2004 #1
    Today at my lunch period, a friend of mine who has a habbit of finding obscure scientific tidbits of information and reciting them without giving or knowing much explanation, said that the male gene was becoming weaker and that eventually males will die out, but by that time females will be able to synthesise sperm most likely.

    Now for obvious reasons, I thought this was total BS, since there are species which have been alive for scores or millions of years and still have both males and females.

    So, is there any stock in these unusual claims, or are they totally unsubstantiated?
     
  2. jcsd
  3. Jan 9, 2004 #2

    russ_watters

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    There are species that have only one sex, but they aren't female - they're aesexual.

    As far as the male gene become "weaker" - no. Thats not how evolution works.
     
  4. Jan 9, 2004 #3
    Males 53% at birth but die off closer to 50/50 by reproduction age.

    Your freind is full of it.

    Nautica
     
  5. Jan 9, 2004 #4

    Monique

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    Actually, somehow I remember that males are weaker embryos and that most embryos that get firtylized (how did you spell that again? :P) are male and that a large part of them dies as an embryo, again bringing it close to 50/50. I have no clue where I got this information so don't trust it, but maybe someone else heard it?

    As for the disappearance of sexes, apparently having a population of different sexes is very beneficial, otherwise it would've never developed. So I find it very hard to believe that something like that would disappear.
     
  6. Jan 9, 2004 #5
    That is true, but that is included in my percentages. Actually, males drop just a bit under 50% by reproduction age, but I figured it would be easier to round.

    Nautica
     
  7. Jan 12, 2004 #6

    Phobos

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    As long as that 50% keeps reaching reproductive age, then males won't die out.
     
  8. Jan 12, 2004 #7

    chroot

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    The Y chromosome IS getting smaller due to competition with genes on the X chromosome. That doesn't mean males are going to die out, though.

    - Warren
     
  9. Jan 12, 2004 #8
    Yes, and the fact they we do not have to put our lives at danger, in order to provide food, should keep it that way.

    nautica
     
  10. Jan 14, 2004 #9

    Another God

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    Genome by Matt Ridley is a great book to read in general, and the chapter dedicated to the X and Y chromosomes (it covers every chromosome in the Human Genome) is all about the Battle of the sexes which occurs on the chromosomal level. It's really cool. It goes into how females, because they only have X chromosomes can develop genes which are fatal to offspring with the Y chromosome. Any females with such a mutation will be unable to have any male offspring unless they somehow find a male mate which has a mutated Y chromosome which makes it resistant to the 'attack' from the partners X chromsome...

    That is why the Y chromosome is so small now...it is the result of a long battle where pot shots taken at it by the X chromosome consistently cause it to loose bits and pieces...

    This fact of life can periodically (you know, once every million years sort of periodically) lead to some sort of freak event where the 'kill all Y chromosomes' mutation becomes prominent and males can't be born. This quickly leads to extinction of the species or quickly leads to one happy male who happens to have the perfect Y chromosome...the last male on earth scenario...he will quickly start spawning many many offspring with more resistent Y chromosomes and the Male proportion of the species will start climbing again....

    As for the claims that us human males are going to go extinct....that is basically BS. We are not under one of these such attacks atm...
     
  11. Jan 18, 2004 #10
    The most quoted reason would be that the Y chromosome is a "loner", and cannot to cross-over to repair any genetic defects like X can (females have 2 X chromosomes ). Also means that X has more possibility of genetic variation.

    Recently shown to be wrong (read in newscientist), as the Y chromosome seems to cross over with itself to repair damage.
     
  12. Jan 18, 2004 #11

    Monique

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    I've been wondering: the Y chromosome has no essential function for the organism, we girls can live happily without it.. there must be a selection against it in every generation, but since a Y person is needed to produce a new generation the net effect is zero.
     
  13. Jan 20, 2004 #12
    There was an article in the Newscientist on this topic a while ago.
     
  14. Jan 20, 2004 #13
    There would only be a selection against it, if it were a detriment did not allow the organism to go on and reproduce.

    Nautica
     
  15. Jan 20, 2004 #14

    Another God

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    Many species have no Y chromosome. They have X chromosome sex, and lack of x chromosome sex. Simple.
     
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