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Re: FW: A Perspective on Cope's Rule

David Marjanovic wrote:

On the one hand, small animals have higher metabolism and therefore more mutations.

I've heard this said a few times: Small mammals have a more rapid metabolism, therefore they generate more free radicals, therefore there is more oxidative damage to the DNA, therefore the DNA accumulates more mutations. However, the genomic DNA is contained within the nucleus, and is endowed with its own suite of DNA-repair enzymes. So, I'm not at all sure that higher metabolism = higher mutation rate is actually true (apart from mitochondrial DNA, perhaps). Do you have references?

Also, the small animals = higher metabolism thing really only holds for endotherms.