Evolutionary Genetics of Fishes

我的研究计划侧重于了解影响不同形态(形态)进化的因素，这些形态出现在同一种群中，是鱼类生活的环境(食物可获得性和栖息地)变化的结果。这一点很重要，因为我们仍然不了解生物多样性是如何产生的，特别是当种群开始在遗传上分化为不同物种时，遗传变异如何在种群之间分割。我研究了来自冰岛的不同形态的北极炭(Salvelinus Alpinus)，它们的身体大小和形状(表型)不同，生活在不同的环境中，有时是在同一个湖里。北极炭仍然是这项工作的模型，因为它们的外观有显著的变化，能够从许多湖泊中捕获它们并产生实验家系。冰岛字符也有一个相对简单的进化史，这使得更容易理清它们进化过程中涉及的不同因素。我提出的研究分为三个部分。首先，我将测试鱼的体型和大小是环境特征的结果，如食物类型(自然选择)或随机过程(遗传漂移和基因流动)，与某一表型鱼的性能改善无关。我还将测试表型和环境之间的关系是否受到种群大小和种群中鱼的遗传变异量的影响，以确定小种群进化和应对环境变化的潜力是否有限。这将包括从冰岛北部熔岩洞穴中生活的19个小种群中重复捕获单独标记的北极木炭。我还将在冰岛的六个湖泊上测试相同的形态表型模式和鱼吃的东西是否相同，这将表明体型是自然选择的结果。其次，我将搜索影响变形体内身体形态和大小的基因，看看这些基因在变形之间有什么不同。在这里，我将寻找来自两个父母(家庭)的后代和来自许多未知家庭的野生鱼的基因和表型之间的关联。我将测试来自同一个湖泊的不同物种之间的遗传差异是否与其他湖泊中不同物种之间的遗传差异相同，以及不同的特征是否由不同的基因控制。第三，我将测试被发现与形态相关的基因是否位于基因组中不同形态之间分歧的区域。这表明，所发现的基因对不同形态的进化很重要。这项研究所产生的知识对于解决新物种是否可以从生活在同一地区的形态中产生这一问题至关重要。**

My research program focuses on understanding the factors that influence the evolution of different forms (morphs) that arise in the same population as the result of variation in the environment (food availability and habitat) where the fish live. This is important because we still do not understand how biodiversity is generated and specifically how genetic variation can become partitioned between populations when they begin to diverge genetically into different species. I examine different morphs of Arctic charr (Salvelinus alpinus) from Iceland that differ in body size and shape (phenotype) and live in different environments, which are sometimes in the same lake. Arctic charr continue to be models for this work because of the remarkable variation in their appearance, the ability to capture them from many lakes and produce experimental families. Icelandic charr also have a relatively simple evolutionary history, which makes it easier to disentangle the different factors involved in their evolution. My proposed research is organized into three sections. Firstly, I will test if the body shape and size of fish is the result of environmental features such as food type (natural selection) or random processes (genetic drift and gene flow) not related to the improved performance of fish with a certain phenotype. I will also test if the relationship between phenotype and environment is influenced by population size and the amount of genetic variation of the fish in the population to see if small populations have limited potential to evolve and respond to environmental change. This will involve repeated capture of individually tagged Arctic charr from nineteen small populations that live in lava caves in northern in Iceland. I will also test if the same patterns of morph phenotype and what the fish eat are the same across six Icelandic lakes, which would indicate that body shape is the result of natural selection. Secondly, I will search for genes that influence body morphology and size within morphs and see how these differ between morphs. Here I will look for associations between genes and the phenotype of offspring produced from two parents (families) and wild fish from many unknown families. I will test if the genetic differences between morphs from the same lake are the same as those between morphs in other lakes and if different traits are controlled by different genes. Thirdly, I will test if the genes found to be associated with morphology are located in areas of the genome that have diverged between morphs. This would suggest that the genes discovered are important for the evolution of different morphs. The knowledge generated by this research is essential to tackling the question of whether new species can arise from morphs living together in the same area. **