Adaptive decoupling in the evolution of complex life-histories

复杂生命史进化中的自适应解耦

• 批准号: 1655092
• 负责人: Ryan Calsbeek
• 金额: $ 34.7万
• 依托单位: Dartmouth College
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-15 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1655092&HistoricalAwards=false
• 关键词: Adaptive; decoupling; evolution; complex; life

All living things change and grow through time. Some of these changes are more dramatic than others. The changes that amphibians (e.g., frogs and salamanders) undergo during development are some of the most dramatic of any of the vertebrates. Metamorphosis is the process by which an amphibian transforms from an animal that lives under water, to one that lives on land. This incredible transition involves reorganizing almost the entire animal's body plan. Many species of amphibians absorb their tails, grow legs for moving on land, and their external gills disappear as they begin breathing air. All of these amazing changes are controlled by a single set of genes. This project will explore the various ways that natural selection has sculpted the amphibian genome to build these two vastly different types of animal bodies with the same sets of genes. Using the wood frog (Rana sylvatica) as a study system, the researchers will explore the role of different environmental factors that can influence the development of both tadpoles and adult frogs. In doing so, the research will determine how the environment interacts with gene expression to influence survival and mating success of wood frogs. Metamorphosis is a fascinating process to watch and provides opportunities for study at multiple age levels. The researchers will involve elementary school students, high school students, and both graduate and undergraduate researchers in the studies. Ultimately, this project will make important contributions to understanding how natural selection influences genes and genomes to make animals that are well suited to multiple environments.A central problem in the study of life history evolution is to understand how tradeoffs play a role in structuring natural populations. This project investigates potential tradeoffs between traits expressed during alternative life stages (i.e., tadpoles versus adults) in wood frogs, Rana sylvatica. For example, tradeoffs may arise across the life history of anurans because their complex life history requires dramatically different forms of adaptation to match changes in ecology, morphology, and behavior following metamorphosis. However, such tradeoffs could be alleviated if genetic correlations are broken apart during metamorphosis (so called "adaptive-decoupling"), or if traits are subject to similar forms of natural selection throughout the life history. Although the idea of adaptive-decoupling is not new, we still understand surprisingly little about the degree to which anuran life-stages are coupled and how this might influence adaptation in each life stage. This project will test for differences in the forms of natural selection between tadpoles and frogs using a combination of semi-natural mesocosms (tadpoles) and field enclosures (frogs). The degree of adaptive-decoupling will be measured using a half-sib breeding design to quantify genetic correlations within and between life-stages. Field surveys of natural populations that vary in predation intensity and timing (e.g., predation at larval and/or adult life stages) will test the prediction that natural selection and adaptive-decoupling interact to influence local adaptation. Further, the researchers will test whether shifts in gene expression and natural selection interact to influence traits important for mating success.

所有的生物都会随着时间的推移而变化和成长。其中一些变化比其他变化更引人注目。两栖动物（如青蛙和蝾螈）在发育过程中所经历的变化是所有脊椎动物中最引人注目的。变形是指两栖动物从生活在水下的动物转变为生活在陆地上的动物的过程。这种不可思议的转变涉及到重组几乎整个动物的身体结构。许多种类的两栖动物吸收了它们的尾巴，长出了腿以便在陆地上移动，当它们开始呼吸空气时，它们的外鳃就消失了。所有这些惊人的变化都是由一组基因控制的。这个项目将探索自然选择塑造两栖动物基因组的各种方式，以建立这两种截然不同的动物身体，拥有相同的基因集。以林蛙（Rana sylvatica）为研究系统，研究人员将探索影响蝌蚪和成年蛙发育的不同环境因素的作用。在此过程中，该研究将确定环境如何与基因表达相互作用，从而影响林蛙的生存和交配成功。变形是一个引人入胜的过程，并提供了在多个年龄段学习的机会。研究人员将包括小学生、高中生、研究生和本科生。最终，这个项目将对理解自然选择如何影响基因和基因组使动物适应多种环境做出重要贡献。生命史进化研究的一个中心问题是理解权衡在自然种群结构中如何发挥作用。本项目研究了林蛙（Rana sylvatica）在不同生命阶段（即蝌蚪与成年）表达的特征之间的潜在权衡。例如，在无尾动物的生活史中，权衡可能会出现，因为它们复杂的生活史需要截然不同的适应形式，以适应变态后生态、形态和行为的变化。然而，如果遗传相关性在变态过程中被打破（所谓的“适应解耦”），或者如果性状在整个生命历史中受到类似形式的自然选择的影响，这种权衡可能会得到缓解。尽管适应解耦的想法并不新鲜，但我们对动物生命阶段的耦合程度以及这种耦合如何影响每个生命阶段的适应，仍然知之甚少。该项目将采用半自然环境（蝌蚪）和野外环境（青蛙）相结合的方法，测试蝌蚪和青蛙之间自然选择形式的差异。适应解耦的程度将使用半同胞育种设计来量化生命阶段内和生命阶段之间的遗传相关性。实地调查不同捕食强度和时间的自然种群（例如，在幼虫和/或成虫生命阶段的捕食）将检验自然选择和适应解耦相互作用影响当地适应的预测。此外，研究人员将测试基因表达的变化和自然选择是否相互作用，影响对交配成功重要的特征。

项目成果

A movie monster evolves, fed by fear

电影中的怪物因恐惧而进化

• DOI: 10.1126/science.aax5394
• 发表时间: 2019
• 期刊: Science
• 影响因子: 56.9
• 作者: Dominy, Nathaniel J.;Calsbeek, Ryan
• 通讯作者: Calsbeek, Ryan

Survival of the Fastest: The Multivariate Optimization of Performance Phenotypes

最快的生存：性能表型的多变量优化

• DOI: 10.1249/mss.0000000000001788
• 发表时间: 2019
• 期刊: Medicine & Science in Sports & Exercise
• 影响因子: 4.1
• 作者: CALSBEEK, RYAN;CAREAU, VINCENT
• 通讯作者: CAREAU, VINCENT

Fitter frogs from polluted ponds: The complex impacts of human‐altered environments

• DOI: 10.1111/eva.12751
• 发表时间: 2019-01
• 期刊: Evolutionary Applications
• 影响因子: 4.1
• 作者: Steven P. Brady;F. J. Zamora‐Camacho;Fredrik A. A. Eriksson-Fredrik-A.-A.-Eriksson-2083519035;D. Goedert;Mar Comas;Ryan G Calsbeek

Experimental Evidence That Metamorphosis Alleviates Genomic Conflict

• DOI: 10.1086/704183
• 发表时间: 2019-09-01
• 期刊: AMERICAN NATURALIST
• 影响因子: 2.9
• 作者: Goedert, Debora;Calsbeek, Ryan
• 通讯作者: Calsbeek, Ryan