Collaborative proposal: Evaluating phenotypic plasticity's role in adaptive evolution

合作提案：评估表型可塑性在适应性进化中的作用

基本信息

批准号：
1754136
负责人：
Cris Ledon Rettig
金额：
$ 20.97万
依托单位：
Indiana University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-06-01 至 2023-05-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1754136&HistoricalAwards=false
关键词：
Collaborative proposal Evaluating phenotypic plasticity

项目摘要

Many organisms can respond to changes in their environment by dramatically altering their morphology, behavior, or physiology, and the widespread occurrence of this ability has provoked a spirited debate. On the one hand, many biologists maintain that the flexibility to change appearance, behavior or physiology are of no relevance to evolution, because evolution requires genetic change. On the other hand, a growing number of researchers have suggested that such flexibility plays a critical role in evolution by jump-starting genetic change. This research will help resolve this controversy by investigating whether changes in appearance, behavior and/or physiology precede (and enable) the evolutionary origins of major, new, genetically-encoded features. The research will specifically evaluate whether pre-existing, diet-induced flexibility has contributed to the evolution of a novel, complex body form in spadefoot frogs. Thus, not only will this research provide important insights into the evolutionary process, it will also shed new light onto one of biology's enduring mysteries: how complex features originate. The research will also promote educational outreach by training school children and undergraduate students and by organizing public talks at museums.This research will test the Plasticity-First hypothesis of adaptive evolution. To do so, the proposed research will focus on spadefoot toads. Like most frogs, tadpoles in the genus Scaphiopus develop only into a typical 'omnivore' morph. By contrast, tadpoles in the genus Spea exhibit striking plasticity: depending on their diet, they develop into either omnivores or a novel 'carnivore' morph. Interestingly, certain components of this distinctive carnivore morph can be diet-induced in Scaphiopus. Moreover, some Spea populations have secondarily lost the omnivore-carnivore plasticity and become monomorphic. Indeed, in some populations, selection has favored the near fixation of the carnivore morph. Thus, as a group, spadefoots appear to represent different stages in the evolution of the novel carnivore morph: from its possible initial induction (in Scaphiopus), to its refinement as part of a novel developmental 'switch' (in many Spea populations), to its ultimate fixation (in some Spea populations). The planned research will evaluate whether this novel carnivore phenotype arose through plasticity-first evolution by contrasting development, genetic variation, and performance in different species/populations that serve as different evolutionary stages in the origins of this distinctive form. In doing so, the research will evaluate the critical predictions of the plasticity-first hypothesis. This research will thereby help to clarify plasticity's role in evolutionary innovation and provide a roadmap for others to test the plasticity-first hypothesis.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

许多生物体可以通过显着改变其形态、行为或生理机能来应对环境的变化，这种能力的广泛存在引发了激烈的争论。一方面，许多生物学家认为，改变外表、行为或生理的灵活性与进化无关，因为进化需要基因改变。另一方面，越来越多的研究人员认为，这种灵活性通过启动基因变化在进化中发挥着关键作用。这项研究将通过调查外观、行为和/或生理学的变化是否先于（并促成）主要的、新的、基因编码特征的进化起源来帮助解决这一争议。该研究将具体评估预先存在的、由饮食引起的灵活性是否有助于铲足蛙进化出一种新颖的、复杂的身体形态。因此，这项研究不仅将为进化过程提供重要的见解，还将为生物学上一个持久的谜团提供新的线索：复杂的特征是如何起源的。该研究还将通过培训学童和本科生以及在博物馆组织公开演讲来促进教育推广。这项研究将检验适应性进化的可塑性第一假说。为此，拟议的研究将集中在铲足蟾蜍上。与大多数青蛙一样，蝌蚪属的蝌蚪只能发育成典型的“杂食动物”形态。相比之下，水蝌蚪属的蝌蚪表现出惊人的可塑性：根据它们的饮食，它们要么发育成杂食动物，要么发育成新的“肉食动物”。有趣的是，这种独特的食肉动物形态的某些成分可以通过饮食诱导。此外，一些Spea种群继而失去了杂食动物-肉食动物的可塑性并变得单一形态。事实上，在某些种群中，选择有利于肉食动物变体的近固定化。因此，作为一个群体，铲脚似乎代表了新的食肉动物形态进化的不同阶段：从其可能的最初诱导（在Scapiopus中），到其作为新的发育“转换”的一部分的完善（在许多Spea种群中），到其最终固定（在某些 Spea 种群中）。计划中的研究将通过对比不同物种/种群的发育、遗传变异和表现来评估这种新型食肉动物表型是否是通过可塑性优先进化产生的，这些物种/种群在这种独特形式的起源中充当了不同的进化阶段。在此过程中，该研究将评估可塑性优先假说的关键预测。因此，这项研究将有助于阐明可塑性在进化创新中的作用，并为其他人测试可塑性优先假设提供路线图。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持标准。