Evolution has nothing to do with progress. Most evolution doesn’t even have anything to do with adaptation, and it is perfectly possible for a change that is worse than useless to spread through a population. Paradoxically, however, such non-adaptive change may be a necessary prelude for major adaptations.
This post was inspired by a recent opinion piece (open access here1) in BMC Biology, entitled “Splendor and misery of adaptation, or the importance of neutral null for understanding evolution” (I will explain what “neutral null” means later). The paper itself is in parts highly technical, with 86 references to the original scientific literature, but I will try here to give a general overview of some of the main conclusions, and to place them in context.
Nothing in biology makes sense except in the light of evolution – Dobzhanski, American Biology Teacher, 1973
Nothing in evolution makes sense except in the light of population genetics – Lynch, PNAS, 2007
Darwin and Wallace both thought that evolution was driven by selection. If so, then whenever we find a feature in an organism, Read the rest of this entry