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

印度尼西亚群岛是一个引人注目的生物多样性热点，拥有丰富多彩的物种丰富度。这种多样性归因于物种形成或物种形成的高速率，在这种情况下，适应不同环境的生物群体最终无法杂交。然而，导致这些物种形成的详细机制尚不完全清楚。在这里，研究人员将研究其中一种机制，特别是测试印度尼西亚原产于medaka鱼（Oryzias sp.）的雄性精致特征是否从雌性偏好的差异中进化而来。该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，阻止自然界中medaka物种的杂交。该项目将在日本进行？北野俊（Jun Kitano）博士是研究鱼类物种的顶尖科学专家，曾与本地鱼类密切合作。梳理新物种产生的行为因素是理解生物多样性如何产生的初始阶段的基础。在进化生物学中，通过性选择证明物种形成仍然是一项具有挑战性的任务。本研究将通过以下方法解决这一长期存在的问题：1)利用定量比色技术详细描述medaka物种姐妹种（O. woworae和O. celebensis）内部和之间的雄性体色变化；2)利用在不同光照环境下进行的配偶选择行为实验，测试雌性对雄性体色的偏好差异。研究结果将为研究雄性显着特征和雌性偏好如何分化提供基础见解，并最终导致印度尼西亚medaka物种之间的早熟隔离进化。NSF EAPSI奖是与日本科学促进会合作资助的。

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.