Evolutionary Genetics of Fishes

我的研究计划侧重于了解影响不同形式（变种）的进化的因素，这些形式（变种）是由于鱼类生活的环境（食物供应和栖息地）的变化而在同一种群中出现的。 这一点很重要，因为我们仍然不明白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成不同物种时，遗传变异是如何在种群之间分配的。我研究了来自冰岛的北极红点鲑（Salvelinus alpinus）的不同形态，它们的体型和形状（表型）不同，生活在不同的环境中，有时在同一个湖泊中。 北极红点鲑仍然是这项工作的模型，因为他们的外观显着的变化，从许多湖泊捕捉他们的能力，并产生实验家庭。 冰岛红点鲑也有一个相对简单的进化历史，这使得它更容易解开参与其进化的不同因素。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否是环境特征的结果，如食物类型（自然选择）或随机过程（遗传漂变和基因流动）与具有某种表型的鱼的性能改善无关。我还将测试表型和环境之间的关系是否受到种群规模和种群中鱼类遗传变异量的影响，以确定小种群的进化潜力和对环境变化的反应是否有限。这将涉及到从冰岛北方的熔岩洞穴中生活的19个小种群中重复捕获单独标记的北极红点鲑。我还将测试在冰岛的六个湖泊中，相同的形态表型模式和鱼吃的东西是否相同，这将表明体形是自然选择的结果。 其次，我将寻找基因，影响身体形态和大小的变形，看看这些变形之间的差异。在这里，我将寻找基因之间的关联和表型的后代产生的两个父母（家庭）和野生鱼类从许多未知的家庭。 我将测试来自同一个湖泊的变种之间的遗传差异是否与其他湖泊的变种之间的遗传差异相同，以及不同的性状是否由不同的基因控制。第三，我将测试与形态学相关的基因是否位于基因组中不同形态之间的差异区域。 这表明，所发现的基因对不同变体的进化很重要。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变种中产生的问题至关重要。 **

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. **