Résumé
Coloration often have an essential role in both the survival and the reproduction of individuals. Becauseof this role, its evolution is determined by multiple, and often opposite, selective pressures. Thesecharacteristics make coloration an interesting trait to understand the fine details of the processes thatshape the evolution of phenotypes. During my PhD, my aim was to disentangle the different selectiveforces influencing the evolution of coloration and to understand the effect of coloration evolution onspecies diversification. Although, there is already a solid literature on these subjects, most of the previousstudies were made at the species levels. The originality of my work lies in the utilization of large-scalecomparative analyses, applied to different species coming from three major clades of vertebrates, Aves,Amphibia and Squamata. I first investigated the selective pressures determining coloration variations atthe intraspecific scale. I showed that, in two species of newt, selection for interspecific recognitioninfluenced the evolution of colorations visible at short range, while selection for crypsis determined thecolorations visible at distance. Secondly, I investigated the selective forces shaping coloration at theinterspecific scale. I studied how coloration mimicry evolves in communities. I developed a new method,based on artificial neural network, to detect mimetic species. I also proposed a new framework to studydefensive mimicry, which emphasizes the role of both cues and signals in the evolution of aposematiccoloration. Besides mimicry, I tested the relative influence of natural and sexual selection on theevolution of coloration in several clades of vertebrates. This analysis highlighted that sexual trait do notalways have higher rates of evolution nor a higher disparity than non-sexual traits. Finally, I focused onthe interplay between the evolution of coloration and species diversification, and I showed that, inLacertids, neither the evolution of sexual colorations nor color polymorphism affected the rates ofspeciation.