Evolution and maintenance of a transspecies color polymorphism

报告题目：Evolution and maintenance of a transspecies color polymorphism

报 告 人：李鸣 助理教授（康茨坦斯大学）

报告人简介：Polymorphisms remain poorly understood in terms of their origin, maintenance, and potential effects on species and speciation. Theoretically, assortative mating based on color polymorphisms might combined with disruptive selection drive speciation perhaps even in sympatry. The extremely young Midas cichlid fish species radiation (13 described species of Amphilophus spp.) from the crater lakes of Nicaragua is characterized by two distinct color morphs that are found in almost all its species. Midas individuals start out as melanic fish, but genetically gold individuals lose the melanophores after about one year and turn bright orange, hence the name based on the Greek god Midas. Yet, despite disruptive selection and almost complete color-based assortative mating, the two color morphs, show only very low genomic intra-specific differentiation. Through a combination of genomic investigations and a number of biological assays we investigated the genetic origin of this transspecific color polymorphism, the ontogenetic mechanisms of color change and the nature of sexual selection based on mate-choice experiments. Our findings offer a likely explanation for why some gene flow continues between the two color morphs, facilitating the maintenance of the polymorphism and why speciation has not happened (yet) based on color assortative mating and sexual selection.

时间：2025年7月17日下午15:00

地点：5号楼学术报告厅

邀请人：林强 研究员