Disruptive selection and the evolution of discrete color morphs in Timema stick insects

Autor(es)

Villoutreix, Romain ; de Carvalho, Clarissa F. ; Feder, Jeffrey L. ; Gompert, Zachariah ; Nosil, Patrik

• Tipo de documento: Artigo Científico
• Fonte: SCIENCE ADVANCES; v. 9, n. 13, p. 14-pg., 2023-03-31.

Resumo

A major unresolved issue in biology is why phenotypic and genetic variation is sometimes continuous, yet other times packaged into discrete units of diversity, such as morphs, ecotypes, and species. In theory, ecological discontinuities can impose strong disruptive selection that promotes the evolution of discrete forms, but direct tests of this hypothesis are lacking. Here, we show that Timema stick insects exhibit genetically deter-mined color morphs that range from weakly to strongly discontinuous. Color data from nature and a manipu-lative field experiment demonstrate that greater morph differentiation is associated with shifts from host plants exhibiting more continuous color variation to those exhibiting greater coloration distance between green leaves and brown stems, the latter of which generates strong disruptive selection. Our results show how ecological factors can promote discrete variation, and we further present results on how this can have variable effects on the genetic differentiation that promotes speciation. (AU)

• Processo FAPESP: 20/07556-8 - Bases genéticas da adaptação em tangarás e soldadinhos (Passeriformes: Pipridae) aos habitats Neotropicais
• Beneficiário: Clarissa Ferreira de Carvalho
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado