Ancestral plasticity and mating system evolution in the stickleback radiation

刺鱼辐射中的祖先可塑性和交配系统进化

• 批准号: 0447480
• 负责人: Susan Foster
• 金额: --
• 依托单位: Clark University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-15 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0447480&HistoricalAwards=false
• 关键词: Ancestral; plasticity; mating; system; evolution

Adaptive radiation occurs when an ancestral population invades many novel habitats, and the daughter populations evolve in response to differences in the patterns of natural selection across habitats. Initially, shifts in behavior may buffer populations from the changing conditions, and differences in the responses to different environments can determine which behavior patterns are exposed to selection in the ensuing years. Thus, the patterns of ancestral plasticity could predispose populations to evolve in particular directions, and could lead to the repeated evolution of divergent patterns of expression across habitats as is seen in a number of recent adaptive radiations. In the post-glacial radiation of the threespine stickleback fish (Gasterosteus aculeatus), ancient oceanic populations have repeatedly given rise to freshwater populations that possess morphological and behavioral features that cause them to be specialized for feeding on plankton (limnetic type) or bottom-dwelling invertebrates (benthic type). Prior research has shown that female mating preferences covary with male color and behavior expression during breeding, and that benthic and limnetic populations differ predictably. However, data also offer evidence of phenotypic plasticity in the expression of these traits in the oceanic ancestor that parallels divergent patterns of plasticity of the two types in the freshwater radiation. This research will involve rearing sticklebacks from three ancestral, oceanic populations, and from three derived freshwater benthic and limnetic populations. Male nuptial behavior and color expression will be compared with female mating preferences before and after exposure to cannibalistic foraging groups, as these groups are the trigger for plastic responses in these traits. Such groups are formed only by oceanic and benthic fish. Plastic expression in the oceanic forms will be used to infer the ancestral condition for comparison with that in the derived types. This research should offer insight into the role of plasticity in adaptive radiation - an exciting and fundamentally important issue in evolutionary biology. Another question that will be evaluated is the intriguing possibility that ancestral phenotypic plasticity could, under certain scenarios, lead to the decoupling of female mating preferences and the norms of reactions of the traits original favored by this selection, a suggestion at odds with the view that signal and receiver characteristics should be tightly coupled. Broader Impact: The research will involve training at least 15 undergraduate students in scientific theory and practice. Clark University offers an especially rich research experience that, for those entering the fifth year masters program, can last as long as five years and result in one or more publications. Data collected from the project will also be used in laboratory exercises that focus on behavior, statistics and evolution. Secondary and college teachers will be able to download exercises and data from a web site free of charge. Finally, this research may help conservationists understand the loss of a very unusual pair of stickleback species that inhabited a single lake in British Columbia, Canada. This pair has been lost to hybridization, and one of the possible explanations is that increased turbidity decreased the effectiveness of visual signals critical to assortative mating. This research will allow us to evaluate the plausibility of this hypothesis.

适应性辐射发生在祖先种群侵入许多新的栖息地时，而后代种群则因栖息地之间自然选择模式的差异而进化。 最初，行为的变化可能会缓冲种群对变化的条件的反应，而对不同环境的反应差异可以决定哪些行为模式在随后的几年中受到选择。 因此，祖先可塑性的模式可能使种群倾向于向特定方向进化，并可能导致在栖息地之间重复进化不同的表达模式，这在最近的适应性辐射中可以看到。 在冰后期辐射的threespine棘鱼（Gasterosteus aculeatus），古老的海洋人口一再引起淡水人口拥有的形态和行为特征，使他们专门为浮游生物（湖沼型）或底栖无脊椎动物（底栖型）。 先前的研究表明，女性交配偏好与男性的颜色和行为表达在繁殖过程中，底栖动物和湖沼动物种群的差异是可以预见的。 然而，数据也提供了证据的表型可塑性，这些特征的表达在海洋的祖先，平行的淡水辐射的两种类型的可塑性的不同模式。 这项研究将涉及饲养刺鱼从三个祖先，海洋人口，并从三个衍生的淡水底栖和湖沼人口。 男性的婚姻行为和颜色的表达将与女性的交配偏好之前和之后暴露于同类相食的觅食群体，因为这些群体是这些特征的塑料反应的触发器。 这些群体仅由海洋和底栖鱼类组成。 海洋型中的可塑性表达将被用来推断祖先的条件，以便与衍生类型中的条件进行比较。 这项研究应该提供了对适应性辐射中可塑性作用的深入了解-这是进化生物学中一个令人兴奋和根本重要的问题。 另一个将被评估的问题是一种有趣的可能性，即在某些情况下，祖先的表型可塑性可能会导致雌性交配偏好与这种选择最初青睐的性状的反应规范脱钩，这与信号和接收器特征应该紧密耦合的观点不一致。 更广泛的影响：该研究将涉及培训至少15名本科生的科学理论和实践。 克拉克大学提供了一个特别丰富的研究经验，对于那些进入第五年的硕士课程，可以持续长达五年，并在一个或多个出版物的结果。 从该项目收集的数据也将用于实验室练习，重点是行为，统计和进化。 中学和大学教师将能够从一个网站免费下载练习和数据。 最后，这项研究可能有助于保护主义者了解一对非常不寻常的棘鱼物种的消失，它们栖息在加拿大不列颠哥伦比亚省的一个湖泊中。 这一对已经失去了杂交，一个可能的解释是，增加浊度降低了视觉信号的有效性至关重要的选择性交配。 这项研究将使我们能够评估这一假设的可行性。