mise sous écran protecteur (1) pression (1) association (1) variation génétique (1) évolution (1) Control (1) Selection (1) Genes (1) Major histocompatibility complex (1) Social groups (1) Pressure (1) Peptides (1) Human beings (1) Heterozygosity (1) Evolution (1) Chance (1) Cells (1) Addition (1) Evolution (1)