Quantitative Genetics of Foraging and Predator Avoidance in Anuran Tadpoles

无尾蝌蚪觅食和躲避捕食者的数量遗传学

• 批准号: 9806293
• 负责人: Mark McPeek
• 金额: $ 16.49万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-08-01 至 2002-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9806293&HistoricalAwards=false
• 关键词: Quantitative; Genetics; Foraging; Predator; Avoidance

McPeek9806293Most organisms in nature are faced with the conflicting demands of trying to acquire enough food for themselves while simultaneously trying not to become food for some other organism (e.g., a predator). Because both resource acquisition and predator avoidance contribute to growth and survival, respectively, the conflict between these two performance measures usually causes a trade-off between two important fitness components. This trade-off has been frequently described in phenomenological terms but, like many ecologically-important features of organisms, its underlying functional and genetic determinants are unknown. Consequently, we know very little about what characters actually influence growth and predator avoidance, and thus we know almost nothing about the evolution of such networks of characters. In this proposal, we describe research to examine the phenotypic and genetic architecture of characters that are hypothesized to determine growth and predator avoidance in bullfrog and green frog tadpoles (Anura: Ranidae). Bullfrogs (Rana catesbiana) and green frogs (Rana clamitans) are most closely related to one another, and they tend to segregate between habitats with different suites of predators. Bullfrogs occur primarily in lakes that support predatory fish, while green frogs occur primarily in ponds that do not support fish but do support predatory dragonflies and salamanders. This segregation appears to be strongly influenced by differences between the two species in their levels of activity, foraging, and their defenses against predatory fish and dragonflies.This pair of species, therefore, offers an excellent opportunity to 1) identify the properties that determine growth and predator avoidance success in a pair of closely related species, 2) examine how the patterns of variation in these properties have changed as these species have adapted to their respective environments, and 3) explore the evolutionary dynamics of these traits and predict their responses to natural selection. To do this, we will conduct two major experiments, both of which examine variation in growth and antipredator performance at the species, population, and individual levels. In the first experiment, we will measure a suite of behavioral and morphological characters that we hypothesize are related to growth and antipredator success. We will make these measurements on a large number of individuals from six populations of each species, and examine patterns of variation among traits. In the second experiment, we will estimate magnitudes and patterns of genetic variation and heritability for most of these traits in a single population of each species. Analyses will test hypotheses about functional and genetic constraints on phenotypic evolution and how couplings among characters have changed during adaptation to different environments.

McPeek9806293自然界中的大多数生物都面临着相互冲突的需求，一方面试图为自己获取足够的食物，另一方面又试图不成为其他生物（例如捕食者）的食物。由于资源获取和捕食者躲避分别有助于生长和生存，因此这两种性能指标之间的冲突通常会导致两个重要的适应度成分之间的权衡。这种权衡经常用现象学术语来描述，但就像生物体的许多生态重要特征一样，其潜在的功能和遗传决定因素尚不清楚。 因此，我们对哪些特征实际上影响生长和躲避捕食者知之甚少，因此我们对此类特征网络的进化几乎一无所知。 在本提案中，我们描述了检查特征的表型和遗传结构的研究，这些特征被假设确定牛蛙和绿蛙蝌蚪（无尾：蛙科）的生长和捕食者躲避。牛蛙 (Rana catesbiana) 和绿蛙 (Rana clamitans) 彼此关系最为密切，并且它们往往会在不同捕食者的栖息地之间进行隔离。 牛蛙主要出现在有掠食性鱼类生存的湖泊中，而绿蛙主要出现在没有鱼类生存但有掠食性蜻蜓和蝾螈生存的池塘中。 这种隔离似乎受到两个物种在活动水平、觅食以及对掠食性鱼类和蜻蜓的防御方面的差异的强烈影响。因此，这对物种提供了一个极好的机会：1）确定决定一对密切相关的物种的生长和躲避捕食者成功的特性，2）检查这些特性的变异模式如何随着这些物种适应各自的环境而改变，3）探索进化过程 这些特征的动态并预测它们对自然选择的反应。 为此，我们将进行两项主要实验，这两项实验均检查物种、种群和个体水平上生长和抗捕食者表现的变化。 在第一个实验中，我们将测量一系列行为和形态特征，我们假设这些特征与生长和反捕食者的成功有关。 我们将对每个物种的六个种群的大量个体进行这些测量，并检查性状之间的变异模式。 在第二个实验中，我们将估计每个物种的单个种群中大多数这些性状的遗传变异和遗传力的大小和模式。 分析将检验有关表型进化的功能和遗传限制的假设，以及性状之间的耦合在适应不同环境过程中如何变化。