Ecomorphology and the Evolution of Phenotypic Divergence in Sunfish

一个成功的个体必须具有营养功能(即吃而不是被吃)以及生殖功能(即交配并产生成功的后代)。这些强大的、有时是不同的压力可能会在觅食和繁殖的最佳表型之间产生权衡。然而，很少有可能研究性选择和营养选择对形态进化的同时影响。最近的实验室和比较研究表明，蓝鳍太阳鱼的形态变异与繁殖和觅食成功密切相关。这些数据表明，雌性在形态上适应了湖泊觅食生态位的需求，而筑巢的雄性在形态上对两性间选择强度的变化做出了反应。本研究探讨了蓝鳍金枪鱼营养形态选择与性形态选择之间的交互作用。从不同湖泊类型采集的种群之间的形态和行为比较将与摄食和繁殖能力的表型变化相关联。实验杂交和对幼虫的普通园艺饲养将试图确定表型变异的遗传基础。在自然湖泊中对雄性筑巢密度的控制将评估个体的行为和形态灵活性的程度，并量化不同社会条件下表型与筑巢成功的关系。这项研究最终可能解决有关性选择和营养辐射在罗米斯属进化中的相对重要性的关键问题。

A successful individual must function trophically (i.e. to eat but not be eaten) as well as reproductively (i.e. to mate and produce successful offspring). These strong and sometimes divergent pressures can create trade-offs between the optimal phenotypes for foraging versus reproduction. However, it is seldom possible to study the concurrent effects of sexual and trophic selection on the evolution of morphology. Recent laboratory and comparative studies show that morphological variation in bluegill sunfish , Lepomis macrochirus, is intimately related to both reproductive and foraging success. The data suggest that females adapt morphologically to the demands of the foraging niches of lakes whereas the morphology of nesting males responds to changes in the intensity of intrasexual selection. The proposed research investigates the interaction between selection on trophic morphology and sexual morphology in bluegill. Morphological and behavioral comparisons among populations collected from different lake types will correlate phenotypic variation in feeding and reproductive abilities. Experimental crosses and common garden rearing of young will attempt to identify a genetic basis for phenotypic variation. A manipulation of nesting male density in a natural lake will assess the degree of behavioral and morphological flexibility of individual males, and quantify the relationship between phenotype and nesting success under different social conditions. This research may eventually address critical questions about the relative importance of sexual selection and trophic radiation in the evolution of the genus lepomis.