Via EurekAlert comes this news release on research into error checking during DNA polymerization. I’m not judging the science; I’m judging the reporting, which includes the following statement:
Everyone knows mutations – genetic mistakes in DNA, the material of heredity – are bad: The more mutations in the cell’s DNA, the higher the risk of cancer developing.
In case the syntax in the title is unfamiliar to you, lemme spell it out for you: MUTATIONS ARE NOT NECESSARILY BAD. Sure, genetic mutations are responsible for diseases such as cancers, but they are also the raw material upon with all other evolutionary forces act. Without mutation, we wouldn’t have evolution. Although natural selection is a fairly important force, evolution can proceed without it. Natural selection, on the other hand, needs heritable variation in order to increase the frequency of alleles that confer the highest fitness in their carriers. That heritable variation comes from mutations.
The entire article is without a single mention of how this research relates to evolutionary biology. I may be biased as an evolutionary biologist, but the first thing I think of when I hear about error prone polymerases is how they are the engine of evolution. Evolution without an imperfect replicator results in a single lineage. It’s stasis, which is the antithesis of evolution.