Pathogen control programs provide a valuable, but rarely exploited, opportunity to directly examine the relationship between population decline and population genetics. We investigated the impact of an ~12‐fold decline in transmission on the population genetics of P lasmodium falciparum infections ( n = 1731) sampled from four clinics on the T hai– B urma border over 10 years and genotyped using 96 genome‐wide SNP s. The most...