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".

Comments

Re:Slashdotters

[niloroth]

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.

so what?

[eobanb]

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.'

Sex and Diversity

[camperdave]

On a serious note, no sex, no evolution

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:

• Mutation. A stray cosmic ray, or bit of radiation hitting the DNA at just the right spot.
• Virus. A virus could inject a change into the DNA strand of the organism.
• Hijacking. Perhaps the organism can take DNA strands from its food, or from another organism and combine them with its own.
• Pre-encoding. The DNA of the organism may actually encode enough information to build several versions of the creature, and which version gets built is random, or determined by the environment, or is cyclical (the way that certain characteristics skip generations).

... or perhaps the creatures are slipping off for a "quickie" while the scientists aren't looking.