Genomic Architecture of Adaptation in Yeast Experimental Evolution

智力优势：生物如何适应新环境是一个重要的进化问题。基因组测序项目目前正在发现种群和物种之间的遗传差异。然而，更难确定这些基因变化中的哪一个引起适应以及如何引起适应。该项目使用受控实验室条件下的酵母菌群的进化来观察进化过程。通过使用新的更便宜，更快的测序方法，进化的酵母菌株的基因组可以被解码并与祖先的创始人细胞进行比较。发现的突变可以被改造成新的菌株，以测试它们单独或组合的效果。这些工程菌株也将用于研究突变如何控制哪些基因在生长条件下是活跃的。最后，该项目将重复进化实验多次，以确定结果的可重复性。研究结果将有助于发现哪些类型的突变负责适应新环境，它们如何导致适应性变化，以及如果进化重复进行，相同的基因获得突变的频率。由于自然环境的复杂性，简化的实验室系统，如这里使用的系统，为测试这些重要问题提供了明显的优势。更广泛的影响：这项工作将在本科和公共科学教育，纳入代表性不足的群体和科学理解方面产生更广泛的影响。邓纳姆有教育本科生，包括妇女，代表性不足的少数民族，并从主要是本科院校的学生强有力的记录。这项研究将使更多的学生参与实质性的，独立的研究。进一步了解进化过程对科学和社会都有好处。特别是，进化的实验证明是一个令人信服的例子，进化的变化在行动。了解适应性也有助于学习如何通过选择来改进驯化的作物、动物和微生物。

Intellectual Merit: How organisms adapt to new environments is an important evolutionary question. Genome sequencing projects are currently discovering the genetic differences found in populations and between species. However, it is more difficult to determine which of these genetic changes cause adaptation and how. This project uses evolution of yeast populations in controlled laboratory conditions to watch evolution in action. By using new cheaper, faster sequencing methods, the genomes of evolved yeast strains can be decoded and compared to the ancestral founder cell. Discovered mutations can be engineered into new strains to test their effects alone and in combinations. These engineered strains will also be used to ask how mutations control which genes are active under the growth conditions. Finally, the project will repeat the evolution experiment multiple additional times to find how reproducible the results are. Results will allow discovery of what kinds of mutations are responsible for adaptation to new environments, how they lead to adaptive change, and how frequently the same genes acquire mutations if evolution is performed repeatedly. Due to the complexity of natural environments, simplified laboratory systems, like the one employed here, offer distinct advantages for testing these important questions. Broader Impacts: This work will have a number of broader impacts in undergraduate and public science education, inclusion of underrepresented groups, and scientific understanding. Dr. Dunham has a strong record of educating undergraduates, including women, underrepresented minorities, and students from primarily undergraduate institutions. This research will allow more students to participate in substantive, independent research. Further understanding of evolutionary processes is a benefit to science and society. In particular, experimental demonstrations of evolution are a compelling example of evolutionary change in action. Understanding adaptation will also be useful to learning how to improve domesticated crops, animals, and microorganisms through selection.