Photo by Sanofi Pasteur.

Over at The Molecular Ecologist, I have a new post up discussing an interesting new modeling paper. It suggests that, for some viruses, variation in the rate of evolutionary change may be driven not by selection imposed by their hosts, but by the dynamics of the viral population within, and spreading among, host individuals.

Viruses based on RNA, as opposed to DNA, generally have very high mutation rates—in part because the process of replicating RNA is more error-prone than DNA replication. But there’s also tremendous variation in the substitution rate between different RNA viruses, even between populations of closely related viruses.

To find out how simple population dynamics could shape this wide variation in substitution rates, go read the whole thing.◼