Cumulative distribution of the amount of the additive genetic variance of a trait (<i>V_A</i>; <i>y</i>-axis) explained by SNPs with a single-marker association test <i>P</i>-value less than a given threshold (<i>x</i>-axis).

<p>(<b>A</b>) A SNP's effect on the trait is correlated with its effect on fitness (τ = 0.5). Note that the population that experienced recent growth (green line; BN+growth) has a lower proportion of <i>V_A</i> accounted for by SNPs at any <i>P</i>-value threshold than the populations that did not recently expand (orange and purple lines; BN and Old growth). (<b>B</b>) A SNP's effect on the trait is independent of its effect on fitness (τ = 0). Here note that the SNPs with low <i>P</i>-values (<0.05) account for most of the <i>V_A</i> regardless of the demographic history of the population. Here and <i>M</i> = 70 kb.