Chargaff's second parity rule lies at the origin of additive genetic interactions in quantitative traits to make natural selection possible.

Abstract

Results and Discussion ABSTRACT Results and Discussion Methods Author contributions Competing interests Data availability References Continuous variation in complex traits enables natural selection Quantitative traits exhibit continuous normal distribution of phenotypic variations because of their polygenic, multi-locus nature. According to the infinitesimal model proposed by Fisher, continuous phenotypic variation of a quantitative trait, influenced by infinitely large number of genetic loci in a population, have normal distribution (Fig. 1a)29. Here we suggest that this bell-shaped distribution also reflects differential selective pressure or fitness of each individual in the population. For example, when cons ...