Forgot your password?
typodupeerror
Science

Human Males Evolve At a Faster Pace Than Females 454

Posted by CmdrTaco
from the can't-say-i'm-surprised dept.
Tisha_AH writes "A report by the Whitehead Institute indicates that the human Y chromosome present in males is evolving at a furious pace. Across the chromosome there can be as much as a 33% difference within humans alone. The portions of the chromosome evolving fastest are related to sperm production."
This discussion has been archived. No new comments can be posted.

Human Males Evolve At a Faster Pace Than Females

Comments Filter:
  • The cynical among us might say that we're finally catching up...

    • Males are not an independent population. And individuals don't evolve, so the notion of evolving males is silly.

      Evolution is something that happens in a population, not in an individual. The female part of out population likely benefits just as much from the continuous changes to the Y chromosome as the male part of the population. Evolutionary speaking, that is. It's unlikely any individual would really care.

      • by Tony (765) on Thursday January 14, 2010 @10:37AM (#30763802) Journal

        Right, but the gene distribution present within the population is indicative of the changes in genotype within the population.

        The notion of evolving males is not silly. That's why peacocks have big bright displays, while peahens are boring brown. (This is even within the wild population of peacocks.)

        This is called "sex selection," and Darwin wrote extensively about it.

        • by mcvos (645701) on Thursday January 14, 2010 @10:59AM (#30764104)

          The notion of evolving males is not silly. That's why peacocks have big bright displays, while peahens are boring brown. (This is even within the wild population of peacocks.)

          This is called "sex selection," and Darwin wrote extensively about it.

          But that doesn't happen independently from the females. In fact, it happens exactly because of the hens. Sexual behaviour is a complex interaction, and the bright displays are only a manifestation of that. It happens because of tastes, roles and behaviours within the entire population, and it's likely that many genes involved in this are carried just as much by the female peacocks, but they only express themselves in the males.

          • by Anonymous Coward on Thursday January 14, 2010 @11:20AM (#30764468)

            Male-only sexual selection has been seen before. I can't remember the species, but its sperm has become cooperative, not swimming solo like your regular sperm, but hooking up in huge clusters, so they can swim faster than the sperm of the competition. Although that case was related to promiscuity, you could theoretically even get effects like this in monogamous species, although at a far lower pace. Suppose a mutation in one sperm stem-cell makes its y-chromosomes contain some useful trait. Then its offspring might stand a better chance beating other sperm from the same individual even.

            • Re: (Score:3, Funny)

              by lupine (100665) *

              Humans are not monogamous. Humans did not evolve as a monogamous species. Pairing may be beneficial to raising children, but humans have a long history of sleeping around.

              Olivia Judson, evolutionary biologist on reproductive organs:
              http://opinionator.blogs.nytimes.com/2008/02/12/a-tyrannical-romance/ [nytimes.com]

              In species where females usually mate with a single male during a breeding episode, penises tend to be small and uninteresting. In those where females mate with several males (whether by choice or by force), penises are typically larger, and come with fancy decorations such as grooves, nobbles, and spikes.

              The nob on the human male penis was specifically designed to scoop out a rivals sperm and deposit seaman deep into the vagina at which point the penis becomes soft so as to not scoop out its own deposit.

          • by tmosley (996283) on Thursday January 14, 2010 @11:48AM (#30765036)
            Females never at any time have access to the Y chromosome, so any evolution that occurs there by definition only effects males. There are numerous examples of male only evolution occurring throughout the animal kingdom.
        • by Trails (629752) on Thursday January 14, 2010 @11:18AM (#30764428)

          It may also represent societal pressures on men.

          Men have a shorter life expectancy, also indicative of stronger pressure on the males of the species.

          For example, if men tend to do more dangerous jobs (soldering, firefighting, etc...) this means the selective process among males is different, possibly harsher.

          In other words, this is proof that men have it tougher than women, so my wife should quit her belly-achin' and bring me a sammich!!!

        • Re: (Score:3, Interesting)

          by Scrameustache (459504)

          The notion of evolving males is not silly. That's why peacocks have big bright displays, while peahens are boring brown.

          That boring brown is camouflage. If a predator comes along, the bright, loud male can be chased away from the camouflaged female covering the eggs.

        • by Maxo-Texas (864189) on Thursday January 14, 2010 @11:55AM (#30765176)

          Possible reasons...
          1) Sperm better resists the flood of estrogen chemicals and produces more babies.
          2) Random chemicals in the environment are mutating the Y gene faster (so change is not coming from a benefit just a lot of random change)
          3) Sperm lasts longer to evade birth control as long as possible.
          Male sperm production is down by about 1/20th of what it used to be the last I read so there is a lot of pressure here.
          4) Mutated sperm trying to develop laser beams to cut through condoms and diaphrams.

      • Re: (Score:3, Informative)

        by ByOhTek (1181381)

        A population doesn't need to be independent, just distinct.

        As TFS said, there is rapid evolution on the Y chromosome in the human race. With the exception of a few anomalies, this means males.

        Yes the female population benefits from this, but these accelerated mutations and shifts in allele frequency are not within the female population, therefor they are not within the group that is evolving at a more rapid pace.

      • by Dishevel (1105119) * on Thursday January 14, 2010 @11:29AM (#30764674)
        Maybe not. The article clearly states though that in this case the Y chromosome is evolving faster. That chromosome is only present in males. So. Males of the human species are evolving faster than the females at this time. These are very simple facts. Only made muddy and complicated by the fact that saying so sounds politically incorrect and as such can not be left alone as fact and must be downplayed.

        God I hate this kind of shit

      • Re: (Score:3, Funny)

        by neoform (551705)

        individuals don't evolve

        This might explain why people who voted for Bush twice in a row.

      • by cream wobbly (1102689) on Thursday January 14, 2010 @11:34AM (#30764758)

        Males are not an independent population, that's correct. It's also a strawman, because they don't have to be. Females are subject to the same mutations, but obviously, they don't express. From TFS: "the human Y chromosome present in males is evolving at a furious pace".

        The rest of what you say is true also. And has nothing at all to do with the subject at hand.

    • Not really. Women don't evolve that much because they have got no selective pressure - there is more demand than there is supply for females.

      • by Nursie (632944)

        Really?

        Because in most of the western world there are more women than men. Of course demand could be for multiple females...

        • Re:The cynical... (Score:5, Insightful)

          by dunkelfalke (91624) on Thursday January 14, 2010 @10:50AM (#30763986)

          Exactly. There are far more lonely men than women and women are lonely often because of their own decision and not because they cannot find anyone. There are also very successful males who have got some kind of a harem. Hugh Hefner is a prime example.

          The old joke demonstrates this pretty well:

          Boy: I have a dick, and you dun have!
          Girl: My mother said, when I grow up, I can have as many as I want

      • Re: (Score:3, Interesting)

        by GooberToo (74388)

        Plastic surgery has drastically reduced selective pressures on women. In fact, I remember hearing one geneticist say once such methods become globally accepted, the rate of human evolution is likely to drastically slow, if not come to a stop.

    • Re:The cynical... (Score:5, Insightful)

      by gad_zuki! (70830) on Thursday January 14, 2010 @10:42AM (#30763874)

      >The cynical among us might say that we're finally catching up...

      Why is shit like this tolerated? If this was said about women then it would be sexist and marked as a troll. But when its about men, its "Interesting." Sadly, making fun of boys and men is standard fare in American society. Every sitcom and commercial has the smart wife and the idiot husband dynamic where the husband cant do something simple but the wife can.

      As an adult this doesnt bother me, I just feel sorry for kids growing up today believing this garbage and we wonder why so many of our boys end up as dropouts and criminals. Perhaps society shouldnt be painting them as morons 24/7 and let them develop some self-esteem.

      • Re:The cynical... (Score:4, Informative)

        by Slur (61510) on Thursday January 14, 2010 @10:48AM (#30763956) Homepage Journal

        It could simply be taken as a form of compliment - specifically, by way of self-deprecation. It's not uncommon, nor considered problematic in many cultures. (As one who has not yet subscribed to any particular culture, I have no opinion as to whether it offends me or not.)

      • Re:The cynical... (Score:4, Insightful)

        by log0n (18224) on Thursday January 14, 2010 @11:42AM (#30764920)

        Sorry you got modded down.. I wholeheartedly agree with this.

        Like you, I could care less now.. but you are correct - ever since the old school women's liberation movement (which was a good and necessary thing) the balance his shifted so that women aren't equals, they are male superiors. Most advertising portrays females as the wise and NECESSARY figureheads of families while men are bumbling with 0 (or equally idiotic) focus. I'm very fortunate in my marriage.. but the occasional times we bump heads, why is the supposition that I'm automatically the one who's wrong?

        The cynical and sexist side of me thinks that this is because women generally still feel inadequate in some capacity.

        But yea.. factor in TV advertising, divorced moms who typically end up with custody ranting about how evil fathers/men are and doctors prescribing away 'boys will be boys' (generally at the request of the mom), future generations will have some serious genetics to do battle with.

        No wonder males are evolving faster than women. Survival of the fittest.. and men are no longer fit in the battle of the sexes.

        • Re:The cynical... (Score:4, Insightful)

          by TheTyrannyOfForcedRe (1186313) on Thursday January 14, 2010 @12:31PM (#30765822)

          TV panders to women because TV is all about selling advertising. Advertising is all about selling crap. Who does the day to day shopping? Unless you're a single guy it's probably a woman. For most goods, advertisers value the eyeballs of women far more than those of men. This is why nearly every TV program that isn't a guy's show (sports/fishing/woodworking/etc) must be palatable to women. If women won't like it it's not on TV.

        • Re:The cynical... (Score:4, Insightful)

          by superdana (1211758) on Thursday January 14, 2010 @12:53PM (#30766246)
          Most advertising portrays females as the wise and NECESSARY figureheads of families while men are bumbling with 0 (or equally idiotic) focus.

          Yeah, let me tell you how great it is to be constantly reminded that my place is in the home. It makes me feel so SUPERIOR. It's a miracle that I can manage to hold down a software development job too, in which my undeniable superiority rakes in 70% as much as the man in the other cube. Thank God for that old school women's lib thing that is obviously no longer necessary.
          • Re:The cynical... (Score:5, Insightful)

            by Anonymous Coward on Thursday January 14, 2010 @03:36PM (#30769274)

            By and large, the idea than women earn less for equal work is incorrect these days. Yes, women earn less, but that's because they choose safer jobs on average (over 90% of workplace deaths are men), they are more likely to take extended periods of time away from their careers for child-rearing (in most places in the world, paternity leave is a pittance compared with maternity leave), they aren't as demanding when they ask for raises, they choose more pleasant indoor jobs at a higher rate than men do, they work fewer hours on average (men work more overtime on average and are more likely to be employed full-time), and other things of this nature. Once you control for factors like this - factors that boil down to women being less committed to their careers on average than men (who are viewed as the bread-winner and judged harshly if they can't provide for their families) you'll find that the sexes are about equal. Sure, you might put in equal work to your male peers, but other women who make different choices bring down the average salary for women. It's not discrimination, it's choice that causes women to earn less on average.

            Look at it this way: if you really could get the same amount of work from a woman at only 70% the cost, who would ever hire men?

            • Re: (Score:3, Insightful)

              by sean.peters (568334)

              By and large, the idea than women earn less for equal work is incorrect these days.

              [citation needed]. Here's one from me: http://en.wikipedia.org/wiki/Equal_pay_for_women [wikipedia.org]

              Yes, women earn less, but that's because they choose safer jobs on average (over 90% of workplace deaths are men), they are more likely to take extended periods of time away from their careers for child-rearing (in most places in the world, paternity leave is a pittance compared with maternity leave), they aren't as demanding when they as

      • Re: (Score:3, Insightful)

        by Alomex (148003)

        Why is shit like this tolerated?

        Because humor is usually either mocking yourself or those who are in power. Everything else is generally considered in poor taste---unless you select the one ethnicity that each country is allowed to hate. In the USA it used to be the "Pollacks", nowadays the French seem to be it.

        People in power always gets their fair share or barbs and Obama as the current president is no exception.

        However you are on to something: as society becomes more integrated and less racist, mock-the

      • Re:The cynical... (Score:4, Insightful)

        by KingSkippus (799657) on Thursday January 14, 2010 @01:41PM (#30767104) Homepage Journal

        It's called self-deprecating humor [wikipedia.org]. I'm a male, so I get to make fun of men. I'm also a white guy, so I can make fun of white guys. I've witnessed African-Americans making fun of the African-American stereotype, and guess what. It's funny. I've also witnessed women making fun of female stereotypes, and guess what. It's funny, too.

        You should try it sometime yourself. Stop taking yourself, your race, your gender, your religion, your [whatever] so seriously. Ironically, most people respect folks more who are able to laugh at themselves. It's people like you are are "that guy" that no one wants to be around because they're so self-righteous.

        I don't feel sorry for our children at all. I want my kids to have a healthy sense of humility and not be like you. And if you think that comments like these about one's own cultural groups are a contributing factor to society's ills, you really need to get a better perspective things.

        In other words, man up, Nancy.

      • Re: (Score:3, Insightful)

        by eples (239989)
        I agree completely - women no longer understand what "equality" means and substitute "domination".
  • Males masturbate more than females, amirite?
    • Er... (Score:4, Funny)

      by Wrexs0ul (515885) <(mmeier) (at) (racknine.com)> on Thursday January 14, 2010 @10:30AM (#30763714) Homepage

      You're correct, males do tend to generate more sperm than females...

      -Matt

    • Males masturbate more than females, amirite?

      Yes, I made the assumption it would be equal, but it is not.

      Last week there was a small reunion of a class 10 years ago, and the "skinny unattractive girl" grown into a hottie, the "hottie" has gone through her batch of men and now has the hottie-attitude, still, yet has settle for far less you would've thought...

      In this context, those two got into a whole sex-conversation, with giggles, what they had tried and such, and we ended up with the all "teen hormone driv

      • Err, women can masturbate all the time, 24/7, and it wouldn't make much difference... eggs will still release on their own set schedule (see also the menstrual cycle).

        Guys OTOH, through either masturbation or sex, have to generate more. Frequent orgasms will over time put the testes into overdrive, generating a higher production rate if I remember right.

    • by Penguinisto (415985) on Thursday January 14, 2010 @10:45AM (#30763928) Journal

      It's not just that, but look at the engineering here...

      Testicles sit outside of the body (because sperm can't handle internal body temperatures for too long), so they get exposed to all kinds of fun stuff: radical temperature extremes, physical abuse, etc. Males generate new sperm all the time from scratch, and in huge frickin' numbers. Sperm cells are built to compete and operate at high energy, requiring high sugars just to survive (after all, they're literally shot into the vagina - or in most /.'ers cases, into something else).

      Women OTOH have all of their eggs tucked inside, deep in the abdomen, where they stay in a nice, consistent environment. IIRC, they also have all of their eggs present in their body when they are born. Women only drop like one egg a month (excepting twins, fertility drugs, etc), so there's no competition or rush for the egg cell as it drifts slowly down the uterus - either into oblivion or fertilization.

    • by mcgrew (92797) *

      Come on, mods, he was clearly joking and clearly the statement is incorrect. Masturbation in no way can make sperm genetically superior. In fact, masturbation would decrease the liklihood of passing genes along -- if you're masturbating, clearly you're not getting any sex.

  • At last... (Score:5, Funny)

    by ls671 (1122017) * on Thursday January 14, 2010 @10:23AM (#30763634) Homepage

    Al least some scientific data ;-)

    Very seriously, I had a feminist girlfriend that wouldn't believe a child sex was defined by the spermatozoid. According to her the female genitals were as much responsible for the sex of the child.

    I guess this article explains everything, she needs more evolution in order to understand those advanced concepts ;-))

    • How the cause of gender selection have any effect on evolution (actually, mutation speed)?
      Males mutate faster, because the Y chromosome has only a single copy.

      About the gender selection.
      The female genitals could have as much responsibility (like the pH value).
      If the environment is hostile to one type of sperm, chances are better for the other type.

      • About the gender selection. The female genitals could have as much responsibility (like the pH value). If the environment is hostile to one type of sperm, chances are better for the other type.

        The inclusion of a X or Y chromosome in a spermatozoa has no effect on its survivability in the female.

        • Re: (Score:3, Informative)

          by afidel (530433)
          But it DOES have an affect on the speed which is why there are slightly more males born than females.
    • Re: (Score:2, Interesting)

      She might not be too far wrong though.

      A slightly acidic environment is likely to kill more Y sperm, which aren't as tolerant as X sperm.

      I can't cite any studies to support this, but have a friend whose OB/GYN told her that as a result of her body chemistry she was unlikely to conceive any boys. (She did manage to beat the odds though and had a boy, and three girls.)

      • That would be interesting if true. Perhaps it is. That said however, I know someone whom never had daughters, only sons. According to him, having a daughter is like having a white buffalo. He said this has always been the case throughout his family lineage. Of course, he's an uber rare exception to the rule of 50/50. However, this conveniences me (and this study) that 99% if not 100% of the child's sex outcome is determined by the father.

        Personally, I think it would suck not to have any daughters. But, what

    • by furby076 (1461805)
      Does she believe that all embryos start as female, and then some (approx half) evolve to male? By that statement, I had to *FIGHT* to be a male. Now I reached that goal and I have to deal with those who were "left behind" or didn't evolve....hmm actually the above was a joke but formed a thought in my head.

      If we start out as females, and have to evolve to be males (hence why males have nipples), does that explain why males evolve faster then females? Maybe because we have to do so to become males?
      • Re: (Score:3, Informative)

        Does she believe that all embryos start as female, and then some (approx half) evolve to male? By that statement, I had to *FIGHT* to be a male.

        Actually, all embryos do start as female. Maybe not genetically, but they develop as a female fetus, and then later in pregnancy the ovaries drop to become testicles and the penis develops. Hormonal and chemical differences in the mother's uterus can prevent this from happening properly (leading to people with a female body who are genetically male), or can lead to

  • by cabjf (710106) on Thursday January 14, 2010 @10:27AM (#30763676)
    I wonder if this would counter the other studies saying that the y chromosome is doomed.
    • by metamechanical (545566) on Thursday January 14, 2010 @10:29AM (#30763700)
      From the very first paragraph of the article:

      Contrary to a widely held scientific theory that the mammalian Y chromosome is slowly decaying or stagnating, new evidence suggests that in fact the Y is actually evolving quite rapidly through continuous, wholesale renovation.

  • by vivaoporto (1064484) on Thursday January 14, 2010 @10:28AM (#30763682)
    Mod the whole article flamebait. The headline plays with the common association between "evolution" and "improvement" in order to gather angry responses and its fair share of taunting.
    • You know, normally I'd lean toward the side of the MIT scientists, but here I'm with you. Sure, there are significant changes, but are allele frequencies changing? That's not there, and to conflate the two - differences and Evolution - is irresponsible.

      • by vivaoporto (1064484) on Thursday January 14, 2010 @10:45AM (#30763924)
        That was not what I meant. The study is probably valid and based on sound science. My point is that the headline should be closer to the point in question "Y cromossome still mutates and mutates fast, contrary of what thought before", but that would not generate enough controversy to pay for this site through advertisement.
    • by fastest fascist (1086001) on Thursday January 14, 2010 @12:15PM (#30765554)

      The headline plays with the common association between "evolution" and "improvement" in order to gather angry responses and its fair share of taunting.

      No it doesn't. "To evolve" is a neutral term, quite apart from "better" and "worse". If people want to get riled up over that, it's their own damn fault.

  • by Snarfangel (203258) on Thursday January 14, 2010 @10:28AM (#30763688) Homepage

    ...at what they are looking for in a mate.

  • Thousands of years of wars fought because of skin tone or beliefs when really we could have done it over +/- 1/2 tsp.

    Is this leading to porn actors trying to subjugate the rest of us as the inferior race?

    • Re: (Score:3, Funny)

      by Penguinisto (415985)

      Thousands of years of wars fought because of skin tone or beliefs when really we could have done it over +/- 1/2 tsp.

      Err, Trojan War? That one has to count

      (no, not the pun damnit, the historical one... :) )

  • by dvoecks (1000574) on Thursday January 14, 2010 @10:31AM (#30763730)
    "Darwin Award" winners are pretty overwhelmingly male.
    • by ArcherB (796902)

      "Darwin Award" winners are pretty overwhelmingly male.

      Evolution is driven by mutation. The vast majority of mutations are not beneficial. The fact that these Darwin Award winners are male only adds evidence that males are evolving at a faster pace than females.

      Fortunately, in order to truly be a Darwin Award winner, you must remove yourself from the gene pool. The Darwin Awards show that evolution works!

    • by MrMr (219533)
      As are Nobel prize winners.
      Yet it is a popular concept that A. proves something about males and B. something about society, and not the reverse.
  • ... for 3D pron [slashdot.org]

  • At least that's how they explained it to us in BIO 101. (Yes I realize it was probably a massive simplification.) The idea was that the Y chromosome has almost nothing on it and is little more than a female to male switch. (All the info for creating a male body are else where in the genome.) If that's sort of correct that means it doesn't really matter if the Y chromosome changes since all it has to get across is the signal "You male, UGG" Anyway if us guys evolve so quickly where are all my super-powers?
  • The researchers said their finding, published this week in the journal Nature, doesn't mean that men are evolving faster than women, though.

    Uhh maybe a less sensationalist headline? [www.cbc.ca]

  • To mate, must make happy one of the opposite sex. Now, the requirements for men are far more complex than for women [boreme.com].
  • by mcgrew (92797) *

    The article doesn't entrely match the summary, especially the title. It says little about the evolution of the X chromosome, only that the Y is evolving faster than they thought it did. TFA makes no comparison between the X and Y chromosomes. There can be in inferrence, as it mentions that the Y has no chance to swap genes as the other chromosomes do.

    It also infers that it's the chimp's Y that is evolving more, and the "better" is sperm production, and it's the difference between how chimps and humans mate.

  • "Evolving" might not be the right term. "Changing" might be better. Simplistically explained, so don't hang me for this: Evolving is genetic changes that is the result of environmental pressure. Evolving therefor results in better adaptation and superior individuals. Any disadvantageous mutation quickly perish. Very few changes are beneficial.

    If there is no or little environmental pressure, any non-lethal mutation survives, and mutations flourish, good and bad.

    If the rate of mutation increases rapidly, it i

    • Re: (Score:3, Informative)

      by Chris Burke (6130)

      "Evolving" might not be the right term. "Changing" might be better.

      Except those are really the same thing.

      Evolution is simply changes in allele distribution in a population over time. That's all it means. It doesn't have to involve mutation, and it doesn't even have to be towards better adaptation. Natural Selection is the mechanism by which these changes can be selected for or against according to their survival benefit and is why evolution generally tends toward better adaptation, but it needn't be so

      • Re: (Score:3, Informative)

        by viking80 (697716)

        Here is an example to illustrate. The facts can be discussed, but understand the point.

        Human brainsize was limited to surviving natural birth. With c-section, this is not an issue, and any brainsize is OK. Since a big brain is a very good survival tool, in not too many generations all infants will have brains too big for natural birth, and can only survive with a c-section. This is certainly evolution, but since we understand and have created this environment artificially, we should also understand what it

  • Old News... (Score:5, Informative)

    by kyriosdelis (1100427) on Thursday January 14, 2010 @10:50AM (#30763988)
    This has been known for a long time. It is called "male driven evolution". This happens because in humans (and most animals) the cells producing sperms divide about 6 times more than the egg cells. And guess what: studies in a human gene that has a homologue in both X and Y chromosomes, showed that (you guessed it) the Y homologue changes about 6 times faster than the X one.
    Did I say old news? 1947 old:
    “The primordial oocytes are mostly if not all formed at birth, whereas spermatogonia go on dividing throughout the sexual life of a male. So if mutation is due to faulty copying of genes at a nuclear division, we might expect it to be commoner in males than females.”
    “ we should expect higher mutability in the male to be a general property of human and perhaps other vertebrate genes.”
    J. B. S. Haldane. 1947. The mutation rate of the gene for haemophilia and its segregation ratios in males and females. Ann. Eugen. 13:262-271.
  • interesting factoid: (Score:5, Interesting)

    by circletimessquare (444983) <circletimessquare&gmail,com> on Thursday January 14, 2010 @10:50AM (#30763992) Homepage Journal

    testicle size in simians is correlated with female permissiveness. such that, in chimpanzees, where a female in estrus is pretty much a gangbang, chimpanzees males have evolved humongous testicles. they need to, because in such a situation, the only strategy available to the male to ensure his genetic continuance is to simply overwhelm other male's sperm with sheer ejaculate volume

    meanwhile, in highly monogamous simians who mate for life, such as gibbons, the testicles are tiny. there's simply no need for so much ejaculate volume, its a waste of resources. she's not going anywhere

    interestingly enough, human males have intermediate sized testicles, owing to the fact that human females are semi-monogamous/ semi-polygamous

    however, i've always wondered why testicles appeared on the outside of the male mammalian body. it seems a ridiculous vulnerability and i've never heard a good explanation as to why. for example, dolphins aren't swimming around with their balls out: the need to be streamlined. of course sperm need a lower temperature to develop, but thats an effect, not a cause. i'm saying wouldn't it be better to have your testicles inside your body and evolve sperm that develop at a higher temperature? its pretty ridiculous to have such an important organ dangling outside unprotected. i never understood why

  • by MagicM (85041)

    I for one welcome our...

    No, it's nasty. I can't do it.

  • Here's a link to the actual paper [nature.com] (rather than the press release), for those who have a subscription to Nature or are willing to pay $32 to read it.

  • just like fruit flys (Score:3, Interesting)

    by cinnamon colbert (732724) on Thursday January 14, 2010 @11:25AM (#30764580) Journal

    Many years ago, I read a serious genetics paper about this. The scientist managed to setup up a colony of fruit flys (drosophilia melanogaster) so that the females remained static - they did not evolve - and the males did.
    In fruit flys, multiple males mate with a female, so there is a lot of competition between the different sperm.
    What happened is that the males evolved their ejaculate to become more aggressive, to outcompete the other males; in some cases, the ejaculate became toxic to the females.

  • by mindbrane (1548037) on Thursday January 14, 2010 @11:27AM (#30764614) Journal
    1st off i'm not going to cite stuff because i've not got it at hand and any citations would be from audio files. the recent courses i've listened to in biology and, more specifically, evolutionary biology suggest the y chromosome is a shrivelled up little thing fast loosing genes. as a guy i didn't much like hearing that either. there's some evidence in some flatworm species that 'penis fencing' suggests bearing young is an "aggressive act" foisted upon a weaker rival. how that would scale up to other species i couldn't say. there are recent findings that male sperm have complex mechanisms that try to induce the egg to draw down from the female as much developmental resources as possible while the egg has similar mechanisms that will try to limited the amount of resources a fertilised egg can demand of the mother. this seems to suggest that there's not only great complexity in development but that sperm and egg are in competition. it's very complex not yet nearly understood stuff. also a 'faster' rate of evolution isn't necessarily a sign of good things to come or an evolutionary edge. what i term differential evolution, for want of a better term, seems not to have been studied or made available to mere lay people such as myself. by differential evolution i mean what does it mean when a species evolves faster. does it simply mean the species has greater fitness? what are the consequences of 'faster' evolution and can such consequences be considered in anything but out of context, almost trivial generalities?

"Life, loathe it or ignore it, you can't like it." -- Marvin the paranoid android

Working...