Faster lizards sire more offspring: sexual selection on whole-animal performance.
Evolution
; 60(10): 2122-30, 2006 Oct.
Article
em En
| MEDLINE
| ID: mdl-17133868
ABSTRACT
Sexual selection operates by acting on variation in mating success. However, since selection acts on whole-organism manifestations (i.e., performance) of underlying morphological traits, tests for phenotypic effects of sexual selection should consider whole-animal performance as a substrate for sexual selection. Previous studies have revealed positive relationships between performance and survival, that is, natural selection, but none have explicitly tested whether performance may influence reproductive success (through more matings), that is, sexual selection. Performance predicts dominance in some species, implying the effects of sexual selection, but how it does so has not been established, nor is it certain whether performance might be a by-product of selection for something else, for example, elevated circulating testosterone levels. We investigated the potential for sexual selection on sprint speed performance in collared lizards (Crotaphytus collaris), considering the potential mediating effects of circulating hormone levels. Among territorial, adult male collared lizards, only sprint speed significantly predicted territory area and number of offspring sired as determined by genetic paternity analysis. Body size, head size, and hind limb length had no effect. Neither plasma testosterone levels nor corticosterone levels correlated with sprint speed, territory area, or number of offspring sired. Thus, our results provide a direct link between whole-animal performance and reproductive success, suggesting that intrasexual selection can act directly on sprint speed performance and drive the evolution of underlying morphological traits.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Corrida
/
Preferência de Acasalamento Animal
/
Lagartos
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
En
Revista:
Evolution
Ano de publicação:
2006
Tipo de documento:
Article
País de afiliação:
Estados Unidos