CONICET | Buscador de Institutos y Recursos Humanos

The increasing availability of molecular phylogenies has brought awareness of the fact 25 that genotype and phenotype patterns of diversification, particularly below the level of 26 species, are not always congruent. This has lead to a widespread idea that traditional 27 classification based on phenotype should be re-assesed. However, lack of complete 28 congruence between both sources of information (phenotypic and genetic) is expected, 29 since they are probably subject to different evolutionary processes. We compared the 30 patterns of diversification in genotype and phenotype in the Blue-black Grosbeak 31 (Cyanocompsa cyanoides), a Neotropical songbird that has four subspecies. Neotropical 32 avifauna is under-represented in studies of this kind, therefore general ideas on avian 33 diversification, such as that the subspecies concept may be useless, are based on biased 34 information. We found that variation in phenotype and genotype are quite congruent 35 between the four subspecies of this species: the group that is more differentiated in 36 genotype, C. c. rothschildii, is also strongly differentiated from the other subspecies in 37 body size, plumage coloration and song, and it should probably be considered as a 38 different species. Of the other three subspecies, two do not show genetic differentiation 39 but do differ in body size and plumage coloration. Even though song is the most plastic 40 character of the three phenotypic traits analyzed, is the one that shows the most similar 41 pattern of variation to that of genotype, showing no differences between the two 42 subspecies that conform a unique genetic clade. The partial congruence we found 43 between phenotype and genotype shows that traditional classification based on 44 phenotype carries valuable information on diversification and variation below the level 45 of species.