Theory 46/Deep Time/Evolution
Evolution Is Mutation Against Selection
The claim
The rate of adaptive evolution is set by the ratio of mutation supply to selection strength, so a large population with weak selection can evolve as fast as a small one with strong selection.
01Mechanism
Adaptation requires both variation and a fitness gradient; the ratio of the two determines the rate at which alleles fix.
02Prediction
Rate should track the ratio.
03Refutation
Rate tracking mutation alone would remove selection.