Neutral theory of molecular evolution

From Palaeos

(Redirected from Neutral Mutation Hypothesis)

The neutral theory of molecular evolution was first formally suggested by Motoo Kimura in 1968, and maintains that the majority of mutations occurring within a population are selectively neutral (i.e. have neither a positive or negative effect), and that genetic drift rather than natural selection is a major factor in differences between populations. While debate still occurs about the relative importance of these two processes, the neutral theory has become the null hypothesis for tests of whether natural selection has occured in a given lineage.

One major implication of this theory is that mutations should accumulate at a fairly constant rate, and therefore the divergence times between lineages should be calculable from the degree of divergence - the so-called molecular clock. The usefulness and correct application of molecular clocks remains a highly contentious subject in studies of evolution.