Organism Survives 100 Million Years Without Sex 343
zyl0x writes "The Times has an interesting article online on the discovery of a 100-million-year-old micro-organism which has survived its entire lifespan without sex." From the article "A tiny creature that has not had sex for 100 million years has overturned the theory that animals need to mate to create variety. Analysis of the jaw shapes of bdelloid rotifers, combined with genetic data, revealed that the animals have diversified under pressure of natural selection. Researchers say that their study "refutes the idea that sex is necessary for diversification into evolutionary species".
...Huh? (Score:4, Interesting)
Gene Transfer? (Score:4, Interesting)
Sorry, I couldn't resist. Seriously however the article was very unclear. What is it that asexual organisms aren't able to do? Surely it isn't that they can't diversify into different species. After all every organism on earth is descended from the same intial life form and some organisms are still asexual hence establishing that the initial lifeform diversified into some progenitor sexual organism as well as branches that remained asexual.
My best guess as to the claim made in the article is that multi-celluar organisms require sexual reproduction to select for organism wide traits. Not sure why it would be true (maybe different cells don't have enough incentive to look out for the whole organism) but that's my best guess.
Anyway saying that the organism doesn't have sex isn't very clear. Many bacteria exchange genetic material without having sex. Such a system might let this creature gain some of the benefits of sexual selection.
Does anyone understand what this article is actually trying to say? I know it's a funny title but some info would be nice too.
Re:Scientific name (Score:3, Interesting)
You can tell everything about what a person believe and thinks simply by asking him who he intends to vote for
Re:Scientific name (Score:5, Interesting)
How on earth can you kill someone who hasn't even been born yet?
Next you'll be saying woman who have periods are murderers.
Re:Welcome to slashdot (Score:2, Interesting)
Re:...Huh? (Score:2, Interesting)
Having no insight in genome map and controlled DNA recombination, that "shotgun" approach is the next best thing for living organisms. Each generation "votes" what they want for the future, at least once in a lifetime (if once, we are probably talking about short-lived organisms which spend most of their lives in larva stage).
Therefore "sexless" species are lucky exceptions, not the norm.
On a side note: IMHO the role of sex in evolution is what invalidates creationists' (im-)probability calculations arguments. Considering where they are coming from (in mind space), it is not a surprise that they didn't recognize sex as THE elusive intelligent designer (not big 'G', but big 'S')
Remember, only YOU can intelligently design future humans!
Re:...Huh? (Score:3, Interesting)
One other thing that makes this news story a little strange is 'Researchers say that their study "refutes the idea that sex is necessary for diversification into evolutionary species".'. It seems like a strange thing to say, since the definition of a species is a group of animals that interbreed and have fertile offspring in the wild.
How do you even clearly define a species if it doesn't have sex?
Re:Welcome to slashdot (Score:4, Interesting)
But aside from that, I'm sure that a lot of women have fallen for slashdot readers precisely because we do have a few things going for us.
1.) We don't think we are god's gift to women, or that we would totally rock if we were on MTV'sTheGrind or whatever. Despite the shortcomings this implies, this means that typically the geek will make a better lover than the frat boy, because he's actually looking for the response from his lover. In short, geeks try harder, and frat boys don't think they have to try at all.
2.) We masturbate. Say what you want, but masturbation is a GOOD THING. The way to become a more effective lover is PRACTICE. And people who masturbate know what gets them off. Just like it's dangerous to assume that being in a relationship with a (member of the preferred sex) will make you a whole person, you shouldn't go into a sexual relationship with the expectations that movies and TV give us. The secret to a good sex life? Non-interdependence.
Go get 'em, tiger.
~Wx
Re:Scientific name (Score:4, Interesting)
Murder means unlawful killing of a human being.
Since in many jurisdictions abortion is not unlawful, it cannot be murder there, although the fetus is obviously a human being. Both sides of the abortion debate are playing silly games with language, cowardly retreating behind abstractions that hide the moral realities. The anti-abortion side falsely try to conclude that the simple fact of being human and innocent is sufficient to warrant extreme social sanctions against being killed, which any innocent young man who has ever been drafted will know is a novel and rarely seen idea. In moronic response to this the pro-choice side declare against all evidence that the fetus is not, in fact, a human being, which makes one wonder what kind of a being it is?
Anyone sane looking at the issue would conclude that: a) a fetus is human and b) killing humans is sometimes justified although always unfortunate and c) in early pregnancy the person who is in the best position to decide if her child would be better off dead is the child's mother. Virtually every human society has practiced some form of infanticide, and infanticide by vacuum suction curatage is a much kinder and more human alternative than anything else that has ever been done.
If you're looking for a grand principle to justify the killing of unwanted children while still in the womb it is simple: every child should be a wanted child, and it is a far greater crime to bring a child into the world unwanted than it is to kill a child in the early stages of gestation, and it is the child's mother who is both in the best position to judge and the only position to act on such a choice.
The abortion debate is populated by two kinds of people: those who see boundaries everywhere, and those who see no boundaries whatsoever. On the one hand, there are those who purport to be unable to tell the difference between a week-old fetus and a year-old baby. On the other, there are those who claim that a baby a week before birth is completely unrelated in every respect to a baby a week after birth. Both groups of people are idiots, and I would dearly love to see them apply the same style of logic to every other aspect of their lives, so they could drive their cars off the road (being unable to tell where the edge is because there is no infinitely sharp division) or wake up each morning wondering where they are, because their house has more dust in it than when they went to bed and so must be a completely different place.
Re:Slashdotters (Score:3, Interesting)
Re:Scientific name (Score:3, Interesting)
Personally, I think science should determine when the fetus starts to feel (emotion, pain, hunger, anything really), and that should be defined as when human life begins. Until that happens, my opinion is that the first trimester should be used as the line between "no questions asked" and "only if mother's health is in serious danger."
Re:Sex and Diversity (Score:4, Interesting)
One should note that there are higher organisms that are parthenogenic as well -- for example, some species of whiptail lizards. Interestingly enough, they often still have to "mate" (even though they're all females) in order to induce ovulation and thus pregnancy. As for the dominant theories considering them:
"One suggestion is that the parthenogenic species are newcomers on the scene, having existed for only hundreds of years, rather than the hundreds of thousands or millions of years of most reptile species (Wright, 1993). It is noted that the geographic ranges of parthenogenic whiptails is significantly less than that of bisexual species (Schall, 1993). Perhaps the parthenogens haven't been around long enough to displace their bisexual competitors.
Another suggestion is that the parthenogenic species are opportunistic 'weeds,' adaptable enough to quickly exploit new or disturbed ecosystems. In support of this hypothesis is the fact that the reproductive capacity per generation for an all female population is (nominally) double that of a population comprising half males. The studies reported in the present work were not of long enough duration to convincingly confirm or refute this notion. The issue remains unresolved. "
(from http://home.pcisys.net/~dlblanc/articles/whiptail
I don't know how long it's been since they diverged, though. Sexual selection and the horizontal genetic drift it allows is an "aid" to evolution, but it's not necessary.