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.

自然界中的大多数生物都面临着相互冲突的需求，即试图为自己获得足够的食物，同时又试图不成为其他生物的食物（例如，捕食者）。由于资源获取和捕食者回避分别有助于增长和生存，这两个性能指标之间的冲突通常会导致两个重要的健身组件之间的权衡。这种权衡经常被描述为现象学术语，但像许多生态重要的生物体特征，其潜在的功能和遗传决定因素是未知的。 因此，我们对什么样的特征真正影响生长和捕食者回避知之甚少，因此我们对这种特征网络的进化几乎一无所知。 在这个建议中，我们描述的研究，以检查的表型和遗传结构的字符，假设确定牛蛙和绿色蛙蝌蚪（无尾目：蛙科）的增长和捕食者回避。牛蛙（Rana catesbiana）和绿色蛙（Rana clamitans）彼此关系最密切，它们往往在有不同捕食者的栖息地之间分离。 牛蛙主要出现在湖泊，支持捕食性鱼类，而绿色青蛙主要出现在池塘，不支持鱼类，但支持捕食性蜻蜓和蝾螈。 这种分离似乎受到两个物种在活动水平、觅食以及对捕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）确定一对密切相关物种中决定生长和捕食者回避成功的特性，2）研究这些特性的变化模式如何随着这些物种适应各自的环境而变化，3）探索这些特征的进化动力学并预测它们对自然选择的反应。 为了做到这一点，我们将进行两个主要的实验，这两个实验都在物种，种群和个体水平上研究生长和反捕食性能的变化。 在第一个实验中，我们将测量一套行为和形态特征，我们假设这些特征与生长和反捕食成功有关。 我们将对来自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。 分析将测试有关表型进化的功能和遗传约束的假设，以及在适应不同环境的过程中，性状之间的耦合是如何变化的。