CONICET | Buscador de Institutos y Recursos Humanos

Different studies suggest that reproductive characters evolve faster than non-reproductivecharacters. Males in the order Squamata have paired copulatory organscalled hemipenes, with high morphological diversity, including differences in size,shape, and ornamentation. Some studies in the species-rich lizard genus, Anolissuggest that genital traits evolve faster than the rest of the body. However, thesestudies were made considering only a few traits, across a wide phylogeny, withoutconsidering species relatedness, which may inflate differences in evolutionary rates.Here, we study two phylogenetic distantly related lizard groups, which differ in thenumber of species, but have similar divergence times. We evaluate as follows: (1)evolutionary rate, models of evolution and phylogenetic signal among the differentgenital and non-genital traits; (2) which kind of traits (genital and non-genital) aredivergent across sister species and (3) whether the species-rich group shows a fasterrate of trait change. We studied 24 Liolaemus lizard species, belonging to twomonophyletic groups that differ in species number: L. elongatus? clade, which hasmore species than L. lineomaculatus? clade. We studied 20 different traits (9 genitaland 11 non-genital) and calculated their phylogenetic signal, evolutionary rateof change and models that best explain the evolutionary change. Our results showthat: (1) in general, genital traits evolve faster than non-genital ones in bothgroups, and both phylogenetic signal and best evolutionary model vary dependingon the trait. (2) Genital traits diverged more among sister species within the L. lineomaculatusgroup, but within the L. elongatus group, both sets of traits showsimilar degrees of divergence. Finally, (3) the species-rich group (L. elongatus),has the highest genital evolutionary rate but also the highest non-genital evolutionaryrate.

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