“…In many insects, amphibians, reptiles, birds, and nonhuman mammals, disease resistance is associated with coloration ( 1 , 2 , 12 , 23 ), a trait that can act as a signal for pathogen resistance in mate choice ( 2 , 3 ). Recent findings have identified associations between disease-resistance MHC genes and coloration in mammals ( 10 , 24 ), amphibians ( 25 ), reptiles ( 26 ), and birds ( 27 ), possibly through pleiotropic effects or the action of “supergenes” ( 1 , 28 ). For example, in some bird species, carotenoid-dependent coloration ( 23 ) can drive mate choice through associations with disease-resistant MHC genes that influence the sensory functions of odor, vision, and hearing ( 24 ).…”