Friday, 16 May 2008

Is it possible to keep evolving without sex?

In a previous post I put forth the idea that viruses or other organisms that have the ability to inject their DNA into cells may do some good for their hosts and not just bad. Maybe we only hear about the bad ones for example. I then went on to suggest this may help us evolve because it could be a way of passing genetic code between species with the virus as the carrier. So as one species gains a beneficial mutation other species gain this mutation as it is passed by viruses.

This is all conjecture at this point but it's certainly an interesting thought. Well... I mentioned it to a colleague and he sent me this link http://news.bbc.co.uk/1/hi/scotland/edinburgh_and_east/7360770.stm of an article about a species of fish that reproduces asexually, meaning it doesn't mix it's dna with another set to encourage variation.

In most species that this happens the lack of variation hinders evolution and often leads to extinction. But not in this case. The article suggests there may be some genetic 'trick' these fish have that allows them to gain DNA from other fish. Apparently the females of this species interact with males of another species to trigger reproduction just not sexually.

Whether or not a virus is used is not the point for me as it's not the idea of a virus perse that's important. I'm really just wondering if maybe there are other ways of transferring DNA changes from one species to another or even within the same species. I just don't know if there's been any research in this area.

So to answer the question in the title of this post. I'm not sure exactly how much this species is evolving but the evidence indicates that it's not devolving which is what would be expected with standard asexual reproduction.
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