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Organism Survives 100 Million Years Without Sex
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".
actually, the main point of the story is that it has changed, has evolved. There is no reason to believe that evolution stops if there is no sex, natural selection is quite happy to use mutation as a tool for evolution, just as it does sex. The difference being that sex tends to speed the process up with different combinations of genes with most offspring.
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...scientists *don't* say "that sex is necessary for diversification into evolutionary species".
Sex *does* lead to diversity *within* a species, which can be good for keeping ahead of parasites and diseases, and all the genetic duplication can help accelerate diversification. But sexual reproduction, in the absence of other sources of genetic variation, does not lead to speciation.
I actually don't see what the big f**king deal is. If you understand evolution, you probably know that natural selection does not depend on sexual reproduction. It just depends on reproduction, period. It's not as if this single, individual organism has lived 100 million years; its asexual offspring have lived that long, and any time in asexual reproduction, mutations can also occur. I repeat, IT IS NOT SPECIFIC TO SEXUAL REPRODUCTION.
I would fathom that mutation might happen more often with sexual reproduction, and thus asexual reproduction could slow the pace of evolution, but again, that's not to say it doesn't happen. Because it very surely does, as we know from the mutation of all those single-celled asexual organisms we know about. Like every disease out there. It is absolutely nonsense to claim otherwise. Bacteria multiply asexually. Protists do too. This is why diseases resist new drugs. Countless species of plants reproduce asexually. Myriad species of all these kingdoms have survived for 100 million years.
The headline might as well be, 'there has been life on Earth a long time.'
Take off every sig. For great justice.
Actually, the standard right wing Christian viewpoint is extremely concise... for sexually reproducing organisms, life begins at conception, the union of a sperm and egg. That's when GOD puts the soul in there. So a woman's menstrual cycle is not murder, as the egg is not alive at that point. If you are going to take a stand as to when abortion is morally wrong, at the very least that is far more concise and easy to legally prove than "before the second trimester" or whatever.
Not that I agree that that's the right place where the law should say life begins, but it far more defensible than some arbitrary time such as second trimester.
I had always read that sex wasn't nessaccary for diversity but it excellerates the process. It would be more of a story if the microorganism had mirrored the diversity of sex based organisms without the benefit of sex. The mutation rate is higher with sex providing for a more varied gene pool and it allows for those genes to be randomly exchanged.
I'm still a virgin, you insensitive clod!
Come on, I know reading the article is too much but you could at least read the summary.
Well now wait a minute. I didn't read the article or anything (you know) but, wouldn't that also imply that the little bugger hasn't "made itself happy" for 100 million years either?
I mean, I haven't ever had sex, but since age 14 I'm sure I've had THOUSANDS of orgasms. (Okay you didn't need to know that - would it help if I mentioned that I'm a girl?)
FTFA: Asexual animals and plants usually die out quickly in evolutionary terms but the ability of bdelloid rotifers to diversify may explain why they have survived so long. A specimen trapped in amber has shown that the animals were living at least 40 million years ago and DNA studies have suggested they have been around for 100 million years. Modern Man has notched up about 160,000 years. It had previously been recognised that asexual animals and plants can evolve through mutations into another species, but only into one species and at the cost of its original form. Bdelloid rotifers have displayed the ability to evolve into many different forms. The article claims that these animals vastly outlived any other asexual organism, attributing its longevity to its ability to diversify while maintaining its form.
Precisely. Any asexual reproductive process, coupled with random mutation and selection will lead to genetic diversity in a population. It just means that the rate of change is dependent on random mutation alone, rather than having the added boost of sexual mixing. Not a non-story, but not an earth-shattering one.
I work in IT. My last date was in December of 2003. It did not go well. That alone makes my time since the year 2000 above average in the "action" department.
Nope, no stereotypes here.
The purpose of sexual reproduction (mitosis) is to blend genetic traits, and thus diversify the species. However, I can think of a number of ways that genes can be modified without mitosis:
When our name is on the back of your car, we're behind you all the way!
e.g. The USA - a 2 party state. Israel - a 12+ party state.
i.e. Clumping is of expediency, not choice. Change the electoral system and left/right loses all meaning. It only has meaning in the US because American politics is one dimensional.
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I always have trouble reading about findings of "two close species". Article claims that they are too different genetically to be one species, too different ecological niches to be one species, yet dispite the differences they find it proving that they are "evolutionary related". If they are too distant then they might be created using non-evolutionary ways (aliens came, looked at the rotifer and decided to make it live in another organ of the lice). If they are similar, then what does prevent us to call asexual organisms one species?
In sexual organisms there is a clear boundary between species - productive progeny of mating between two organisms. If a couple does not produce productive progeny - male and female belong to different species, if they do - they are from the same species. That is why using asexual organisms to support pseudo-science of evolution is particularly lame: all the arguments are tautologically meaningless reducing themselves to "diversity".
About that: authors write First of all, that has been traditional view long time ago, but evolutionists have been convinced that sex is not necessary for evolution for quite some time. And you do not have to be a specialist to know that. Look at bacteria.
Second. How would you know if clades are displaying the same pattern or different pattern or any pattern, if you for sure do not know all the representatives of the clade that ever existed? For example, according to "traditional" view of evolutionists reptiles were much more diversed before 100M years ago than they are now.
It is essentially comparing diversity of two arbitrarily (which is different from randomly) selected samples. And the difference between "arbitrarily" and "randomly" is that first is biased selection (some species exist no more for all kinds of reasons).
And this is a beginning of the article.
I do not believe in karma. "Funny"=-6. Do good and forbid evil. Yours, Oft-Offtopic Flamebaiting Troll.
The parent poster id mostly correct. However, not all single celled organism reproduce "clonally" or, asexually. Some do, some don't, some do both. It's true that more genetic diversity comes by combining the genetic material of two different haploid cells (sperm and ovum), but some diversity as the parent poster pointed out, mutations are a source of diversity. Most mutations are harmful, but when you have a population of, hell, I don't even know what the numbers are for and individual species of rotifers, but it's subtantially higher than the human population by anywhere from a factor of tens of thousands to billions or more, but the point is, their numbers are so extremely high, that you're bound to have a large number of beneficial mutations and these are enough to provide the necessary diversity and change.
Just to give you an idea of how many rotifers there are, go pick up some dried lawn clippings from your back yard, throw them in a glass of water (let it sit over night before adding the grass so the chlorine can evaporate). Then a couple days later, take a look in a microscope. You'll probably find thousands of rotifers in your glass of water. Of course, this assumes that, like me, you're a biology geek and you have a microscope.
Personally, I think rotifers are amazingly cool to watch. I've spent many an hour watching them feed and, being completely transparent, digest, and then excrete material. Because some remain relatively stationary, they're much easier to view than say a paramecium which zips around (though you can get viscous additives to slow them down).