The functions of sexually selected traits are particularly sensitive to changes in the environment because the traits have evolved to in-crease mating success under local environmental conditions(Rosenthal and Stuart-Fox 2012).When environmental conditions change,previously reliable signals may become less reliable or harder to detect and evaluate.Because the correct expression,trans-mission,and interpretation of sexual signals typically influence mate choice outcomes,impediments to sexual signals can change both the strength and the direction of sexual selection(Rosenthal and Stuart-Fox 2012).Artificial light is a major anthropogenic disturbance that is intensifying around the world and has high potential to negatively impact wildlife,for example by hampering the expression and detec-tion of sexual signals.For instance,the bioluminescent signals of fireflies are often inhibited or obscured by artificial illumination(Rosenthal and Stuart-Fox 2012;Owens et al.2020).The evolution of more detectable signals could,at least partly,mitigate the nega-tive effect of artificial light on mate attraction.However,whether sexual selection for signal conspicuousness will result in an evolu-tionary response depends on the heritability of the signal and the factors that constrain signal evolution.These include physiological and morphological limitations,costs of signaling,and trade-offs in allocation of energy to different traits(Andersson 1994;Jennions et al.2001).