Digit identity matters: origin and evolution of sexual dimorphism in the digit lengths of tropidurid lizards

Autor(es)

Lofeu, Leandro ^[1] ; Brandt, Renata ^{[1, 2]} ; Kohlsdorf, Tiana ^[1]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Biol, FFCLRP, Ave Bandeirantes 3900, BR-14040900 Ribeirao Preto, SP - Brazil

^[2] Sci North, 100 Ramsey Lake Rd, Sudbury, ON P3E 5S9 - Canada

• Tipo de documento: Artigo Científico
• Fonte: Biological Journal of the Linnean Society; v. 131, n. 1, p. 109-121, SEP 2020.
• Citações Web of Science: 0

Resumo

Sexual dimorphism in digit lengths reflects phenotypic evolution mediated by developmental steroids. Differences in the identity of the sexually-dimorphic digit may evolve if the concentrations of sex-steroid receptors in the digit are easily modified and the initial changes have low impact on fitness. Accordingly, sexual dimorphism in digit lengths might initially originate under neutral selective regimes, being subsequently co-opted by embryonic hormonal effects on sensitive traits that are more likely to be targeted by selection. Correlated variation among sexually-dimorphic traits might therefore reflect pleiotropic hormonal modulation during development. Moreover, the identity and trend of the sexually-dimorphic digit might be evolutionarily labile even among closely-related species. We evaluated this model by assessing the identity of sexually-dimorphic digits among 11 Tropiduridae lizard species and inferring evolutionary patterns of sexual dimorphism. Assuming that digit lengths can be used as a proxy for hormonal modulation of steroid-sensitive traits during development, we tested for evolutionary associations among sexual dimorphism of digit lengths, body size and other traits that may be direct targets of sexual selection in the Tropiduridae. Sexual dimorphism in digit lengths is evolutionarily labile in the Tropiduridae, and diversity, instead of conservatism, seems to rule developmental mechanisms underlying the evolution of sexual dimorphism in digit ratios. (AU)

• Processo FAPESP: 13/14125-0 - Análise integrativa do dimorfismo sexual em lagartos: morfologia, significado funcional e seleção
• Beneficiário: Renata Brandt Nunes
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 15/07650-6 - Ecologia, evolução e desenvolvimento (Eco-Evo-Devo) na herpetofauna brasileira
• Beneficiário: Tiana Kohlsdorf
• Modalidade de apoio: Auxílio à Pesquisa - Temático