The Neutral Theory in Light of Natural Selection

Abstract

In this perspective, we evaluate the explanatory power of the neutral theory of molecular evolution, 50 years after its introduction by Kimura. We argue that the neutral theory was supported by unreliable theoretical and empirical evidence from the beginning, and that in light of modern, genome-scale data, we can firmly reject its universality. The ubiquity of adaptive variation both within and between species means that a more comprehensive theory of molecular evolution must be sought.

Fig. 1.

Correlation coefficients (“tau”) between levels of polymorphism and recombination rate from 40 genomes belonging to various multicellular subgroups (data from Corbett-Detig et al. 2015).