Evolutionary response to environmental uncertainty

对环境不确定性的进化反应

• 批准号: RGPIN-2015-03922
• 负责人: Simons, Andrew
• 金额: $ 2.33万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684271
• 关键词: Evolutionary; response; environmental; uncertainty

Natural environments are constantly changing; changes can be of any magnitude and occur over all time scales. Over 99% of species that have inhabited this planet are now extinct, and the remaining species are representatives of evolving lineages that have survived all change. Study of adaptation to change has broad applicability; for example, evolution of infectious disease-causing microbes is a story of rapid adaptation to new (host) environments. Despite its importance, much remains to be learned about how organisms evolve to cope with change. We do know that adaptation takes three main forms: 1) evolutionary "tracking" of the environment as it changes, 2) the evolution of the ability to make plastic adjustments to suit the circumstances within an organism's lifetime, and 3) the evolution of safe or "bet-hedging" characteristics to avert risk during hard times (analogous to purchasing insurance). Little is known about the relative importance of these three forms of adaptation, or how they interact to influence survival through future change. The research supported by this NSERC Discovery Grant will lead to progress in the understanding of organismal response to environmental variation by using novel experimental laboratory and field approaches.*** In an experimental evolution study, we will subject the fungus Neurospora crassa to variable environments to observe evolution directly. We aim to discover how important the past pattern of changing environments is to the evolution of traits that allow it to survive into the future. We will then use DNA sequencing techniques to identify the genes that are involved in this adaptation to change. Using duckweed, the smallest flowering plants in the world, we will ask what mechanisms allow survival through harsh times. The aquatic species we study survives winter by producing "turions" that sink to the bottom of ponds. To better understand adaptation to unpredictable season length, we will study the relative importance of innate and environmental differences in determining the phenology of turion production. In another set of studies, we will use "DNA fingerprinting" techniques to directly study the effect of variable environments on the fate of genotypes of herbaceous plants in the field. Finally, we use information contained in tree rings to inform us about how variable particular environments have been, and then ask whether adaptations in herbaceous plants in the same environments are as would be predicted, and what the nature of these adaptations are. Thus, we use a wide array of experimental systems that enable us to address problems all unified by the central question of how organisms evolve in response to environmental variation. This fundamental research provides knowledge that has potential applications important to Canada ranging from response to climate change to medicine.**

自然环境是不断变化的；变化可以是任何大小，发生在所有时间尺度上。居住在这个星球上的超过99%的物种现在已经灭绝，剩下的物种是进化血统的代表，它们在所有变化中幸存下来。适应变化的研究具有广泛的适用性；例如，传染病致病微生物的进化是一个快速适应新(宿主)环境的故事。尽管它很重要，但关于有机体如何进化以应对变化，仍有许多需要了解。我们知道，适应有三种主要形式：1)在环境变化时对环境进行进化“跟踪”；2)进行可塑性调整以适应生物体一生中的环境的能力的进化；3)在困难时期为避免风险而进化的安全或“避险”特征(类似于购买保险)。关于这三种适应形式的相对重要性，或者它们如何相互作用，通过未来的变化影响生存，人们知之甚少。这项由NSERC Discovery Grant资助的研究将通过使用新颖的实验室和现场实验方法，在理解生物对环境变化的反应方面取得进展。*在一项实验进化研究中，我们将使真菌粗糙脉孢菌在不同的环境中直接观察进化。我们的目标是发现环境变化的过去模式对使其能够存活到未来的特征进化有多么重要。然后，我们将使用DNA测序技术来识别参与这种适应变化的基因。以浮萍这种世界上最小的开花植物为例，我们将询问是什么机制让它们能够在艰难的时期存活下来。我们研究的水生物种通过产生下沉到池塘底部的“青葱”来生存。为了更好地理解对不可预测的季节长度的适应，我们将研究先天和环境差异在决定Turion生产物候方面的相对重要性。在另一组研究中，我们将使用“DNA指纹”技术，直接研究不同环境对田间草本植物基因类型命运的影响。最后，我们使用树木年轮中包含的信息来告知我们特定环境的变化程度，然后询问草本植物在相同环境中的适应是否如预期的那样，以及这些适应的性质是什么。因此，我们使用了广泛的实验系统，使我们能够解决所有由生物体如何随着环境变化而进化这一中心问题统一起来的问题。这项基础性研究提供了对加拿大具有重要潜在应用的知识，范围从应对气候变化到医学。