concept

Differential persistence

A way of stretching the Darwinian frame so that selection can act even on entities that do not reproduce - such as a lone planet. Classical Darwinian selection needs a population of competing, reproducing individuals with heritable variation; but W. Ford Doolittle argued that selection can also operate purely through *lasting longer*. Systems that happen to stumble into stabilising feedback loops persist; systems that do not collapse fast. Over geological time the surviving systems are, trivially, the ones whose feedbacks held - a "selection by survival alone" that needs no offspring. It pairs with the slogan *it's the song, not the singer*: species come and go, but the biogeochemical cycles they perform are carried on by whoever is recruited to sing them next. It is a genuine loosening of the Darwinian frame, and it remains contested.