From John King
Colin Barras’s article on plasticity proposes that advantageous behaviour can persist until a compatible mutation makes it permanent and a base for further change (17 January, p 26).
For a long time I have struggled to see how evolution could have worked in the limited time available. Conventional thinking requires each evolutionary step to be a coincidence of two unlikely events: a genetic mutation and a change of behaviour. In the period between one and the other, no benefit and some disadvantage is usually on offer.
Plasticity is one of those light-bulb ideas which explain so much; once recognised it seems obvious, and we are left wondering why we hadn’t thought of it before.
Wymondham, Norfolk, UK
