Monday, March 8, 2010

Still running

Alice in Wonderland Barbie and friends.

As we come to the end of our first quarter I think it's time we returned to the Red queen hypothesis. Although much data is consistent with the red queen hypothesis and it helps explain numerous phenomena, it has been hard to directly test it because of the time scales involved with evolutionary processes.

However in Nature recently a group of workers from the University of Liverpool (and elsewhere) used experimental populations of bacteria and their viral pathogens to directly test the hypothesis.
Antagonistic coevolution accelerates molecular evolution
(T)he rate of molecular evolution in the phage was far higher when both bacterium and phage coevolved with each other than when phage evolved against a constant host genotype. Coevolution also resulted in far greater genetic divergence between replicate populations, which was correlated with the range of hosts that coevolved phage were able to infect. Consistent with this, the most rapidly evolving phage genes under coevolution were those involved in host infection. These results demonstrate, at both the genomic and phenotypic level, that antagonistic coevolution is a cause of rapid and divergent evolution, and is likely to be a major driver of evolutionary change within species.

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