Experimental analysis of adaptation in plants: from reproduction to range limits

植物适应的实验分析：从繁殖到范围限制

• 批准号: 155045-2007
• 负责人: Eckert, Christopher
• 金额: $ 4.39万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2009
• 资助国家: 加拿大
• 起止时间: 2009-01-01 至 2010-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=422443
• 关键词: Experimental; analysis; adaptation; plants; reproduction

Natural selection is widely viewed as the principal evolutionary force shaping the diverse adaptations that make organisms so well suited to their physical and biological environments. Yet, scientists are still learning how selection interacts with other processes of evolution (mutation, genetic drift and gene flow) in complex natural habitats. This research addresses two enduring and unresolved problems in evolutionary biology. First, I will continue a productive investigation into the evolution of inbreeding, particularly self-fertilization in plants. While many organisms reproduce by mating with unrelated individuals, selfing has evolved thousands of times, with profound ecological and genetic consequences. I will also continue relatively new research to understand the evolution of geographical range limits. Virtually all organisms have limited distributions, which poses a difficult problem: why does natural selection not cause populations at the limits to adapt to local conditions and spread outward? Because these two problems involve interactions among the major evolutionary forces, thorough analysis can change our fundamental understanding of evolution. Both problems have been analyzed using mathematical models, but there is a clear need for experimental tests of these models. To this end, we will perform surveys of geographic variation, molecular-genetic assays, manipulative experiments in natural habitat and genetic experiments in controlled environments using a set of flowering plants proven to be exceptional experimental subjects. Our long-term goals are to better understand (1) how natural selection shapes reproductive behaviour; (2) how selection interacts with the other evolution processes; (3) the genetic and ecological constraints on adaptation; and (4) how evolutionary forces play out across multiple spatial scales. This research will help provide answers to fundamental questions in biology that can contribute to the conservation of rare species and the management of exotic invaders, and will train graduate and undergraduate students in valuable and transferable skills such as (i) modern genetic techniques, (ii) field biology in a variety of ecosystems, and (iii) experimental design and recent advances in statistical analysis.

人们普遍认为，自然选择是形成各种适应的主要进化力量，使生物体非常适合其物理和生物环境。然而，在复杂的自然栖息地中，选择是如何与其他进化过程（突变、遗传漂变和基因流动）相互作用的，科学家们仍在研究当中。这项研究解决了进化生物学中两个持久且未解决的问题。首先，我将继续对近亲繁殖的进化进行富有成效的研究，特别是植物的自交受精。虽然许多生物通过与不相关的个体交配来繁殖，但自恋已经进化了数千次，产生了深远的生态和遗传后果。我还将继续进行相对较新的研究，以了解地理范围限制的演变。事实上，所有生物的分布都是有限的，这就产生了一个难题：为什么自然选择没有使处于极限的种群适应当地条件并向外扩散？因为这两个问题涉及主要进化力量之间的相互作用，彻底的分析可以改变我们对进化的基本理解。这两个问题都用数学模型进行了分析，但显然需要对这些模型进行实验测试。为此，我们将使用一组被证明是特殊实验对象的开花植物，进行地理变异调查、分子遗传分析、自然栖息地的操纵实验和受控环境中的遗传实验。我们的长期目标是更好地理解：(1)自然选择如何塑造生殖行为；(2)选择如何与其他进化过程相互作用；(3)适应的遗传和生态制约；(4)进化力量如何在多个空间尺度上发挥作用。这项研究将有助于解答生物学中的基本问题，有助于珍稀物种的保护和外来入侵者的管理，并将培养研究生和本科生有价值的和可转移的技能，如(i)现代遗传技术，（ii）各种生态系统中的野外生物学，以及（iii）实验设计和统计分析的最新进展。