PMC

The red horizontal line shows the proportion of SNPs with signature of recent positive selection among GWAS-detected SNPs associated with risk of common human diseases.

Upper panel shows the distribution of selection coefficients: negative values imply negative and positive values positive selection. A change in the environment or life style leads to changes in selective values of existing variants making some of previously neutral variants deleterious and others advantageous. The lower panel shows frequency distributions of risk alleles immediately after changes in environment/life style and after the negative selection took place.

F—frequency of the risk-associated allele. Area under each curve equals 1. Black line shows the distribution expected under the assumption that the probability of the allele to be risk associated is independent of its frequency. a) Proportions of the risk alleles in the 5 frequency categories for diseases stratified by the ELI tertiles. b) Proportions of the risk alleles for 3 individual diseases from the first tertile (environment/lifestyle independent diseases). c) Distributions of risk alleles for 3 individual diseases from the third ELI tertile (environment/lifestyle dependent diseases). d) Proportions of the risk alleles averaged for the 3 environment/lifestyle dependent (red line) and 3 environment/lifestyle independent (blue line) diseases.