Competition and the Origins of Diversity: An Empirical Test of the Ecological Speciation Hypothesis

竞争与多样性的起源：生态物种形成假说的实证检验

• 批准号: 0234714
• 负责人: David Pfennig
• 金额: $ 35万
• 依托单位: University of North Carolina at Chapel Hill
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2003
• 资助国家: 美国
• 起止时间: 2003-03-01 至 2007-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0234714&HistoricalAwards=false
• 关键词: Competition; Origins; Diversity; Empirical; Test

Ecological mechanisms that lead to speciation (the evolutionary splitting of one species into multiple new species) are central to general theory synthesizing ecology and macroevolution. Although competition for resources has long been viewed as the major mechanism by which natural selection would lead to divergence of organism traits, there are few conclusive examples of competition promoting speciation. The proposed research will provide a rare and strong test of the ecological speciation hypothesis in a system of co-occurring spadefoot toad species.Specifically, it will test whether competition among larvae of the spadefoot toads, Spea bombifrons and S. multiplicata, is leading to ecological speciation. This research will evaluate the general hypothesis that populations of S. multiplicata that do and do not occur with S. bombifrons are becoming reproductively isolated from one another because of contrasting competitive pressures faced by their larvae. The goals will be to test the following three predictions: (1) hybrids from crosses between populations should be less fit than offspring from matings within populations because of selection against hybrids; (2) traits under divergent selection between environments should influence mate choice and thereby form the basis of reproductive isolation; and (3) divergence in these traits should evolve in parallel in different populations that experience similar selective pressures. This project will form a decisive test of ecological speciation and will enhance our understanding of how competition promotes adaptive radiation. This study will, therefore, help explain the origins of diversity, which is one of the most challenging issues confronting biologists.

导致物种形成的生态机制（一个物种进化分裂成多个新物种）是综合生态学和宏观进化的一般理论的核心。 虽然对资源的竞争一直被认为是自然选择导致生物性状分化的主要机制，但很少有竞争促进物种形成的决定性例子。 这项研究将为生态物种形成假说提供一个罕见的强有力的测试，在一个系统中共存的铲足蟾蜍物种。multiplicata，is leading导致to ecological生态speciation物种. 这项研究将评估一般假设，即人口的S。multiplicata，与S发生和不发生。由于其幼虫所面临的竞争压力形成鲜明对比，因此，在繁殖上，bombifrons相互隔离。目标是检验以下三个预测：（1）由于对杂种的选择，来自种群间杂交的杂种比来自种群内交配的后代更不适合：（2）在不同环境之间的趋异选择下的性状应该影响配偶选择，从而形成生殖隔离的基础;（3）在经历相似选择压力的不同群体中，这些性状的差异应该是平行进化的。 该项目将形成生态物种形成的决定性测试，并将提高我们对竞争如何促进适应性辐射的理解。 这项研究将有助于解释多样性的起源，这是生物学家面临的最具挑战性的问题之一。