EAPSI:Does Sexual Selection Promote Color Diversification in Southeastern Asian Medakas?

印度尼西亚群岛是一个显著的生物多样性热点，拥有丰富多样的物种。这种多样性归因于物种形成或物种形成的高速率，其中适应不同环境的生物群体最终无法杂交。然而，导致这些物种物种形成的详细机制尚不完全清楚。在这里，研究人员将研究这些机制之一，特别是测试是否男性精心制作的青鳉鱼（Oryzias sp.）从女性偏好的差异中进化而来。这项研究还将测试雌性对不同雄性颜色类型的偏好是否可能作为一种行为隔离机制，防止青鳉物种在自然界中杂交。该项目将在日本？北野纯博士是鱼类物种形成方面的领先科学专家，他与当地鱼类密切合作。梳理新物种产生的行为成分对于理解生物多样性如何产生的初始阶段至关重要。通过性选择来证明物种形成仍然是进化生物学中一项具有挑战性的任务。这项研究将解决这个长期存在的问题：1）详细描述青鳉种内和姐妹种之间的雄性体色变化。woworae和O. 2）在不同光照条件下，通过择偶行为实验，探讨了雌性对雄性体色偏好的差异。研究结果将提供基本的见解如何性选择男性的显着特征和女性的偏好可以发散，并最终导致印尼青鳉物种之间的交配前隔离的演变。这个NSF EAPSI奖是与日本科学促进协会合作资助的。

The Indonesian islands are a remarkable biodiversity hotspot that harbor abundant and colorful species richness. The diversity is attributed to high rates of speciation or species formation, where groups of organisms that adapt to different environments ultimately become unable to interbreed. Yet, the detailed mechanisms leading to speciation in these species are not completely known. Here, the researcher will examine one of these mechanisms, specifically testing whether male elaborate traits in medaka fishes (Oryzias sp.) native to Indonesia have evolved from differences in female preference. The research will also test whether female preference for different male color type might serve as a behavioral isolating mechanism, preventing medaka species from interbreeding in nature. The project will be conducted at Japan?s National Institute of Genetics, with Dr. Jun Kitano, a leading scientific expert on fish speciation who has worked closely with the native fish. Teasing apart the behavioral components by which new species arise is fundamental to understanding the beginning stages of how biodiversity is generated.Demonstrating speciation by sexual selection is still a challenging task in evolutionary biology. The proposed research will tackle this longstanding issue by 1) characterizing in details male body color variation within and between sister-species of medaka species, O. woworae and O. celebensis, using quantitative colorimetric techniques, and 2) testing for variation in female preference for male body coloration using mate choice behavioral experiment conducted under different light environments. The results will offer fundamental insights on how sexually selected male conspicuous traits and female preference can diverge and ultimately lead to the evolution of premating isolation between Indonesian medaka species. This NSF EAPSI award is funded in collaboration with the Japanese Society for the Promotion of Science.