Selection and evolution of coat colour in a wild mammal

该项目提供了研究进化遗传学的机会，作为Soay绵羊项目的一部分，该项目是世界上任何脊椎动物数据最丰富的长期研究之一。我们将有机会参观联合国教科文组织世界遗产圣基尔达（St Kilda）并在那里工作。了解遗传和表型变异如何响应环境条件的变化仍然是进化生物学面临的最大挑战之一。十年前，我们在《科学》杂志上发表了一篇论文（Gratten et al. 2008），展示了野生Soay绵羊种群中TYRP 1基因的等位基因变异是如何在自然选择下保持毛色多态性的，以及TYRP 1的变异是如何保持的。在接下来的十年里，圣基尔达的环境发生了变化，人口规模增加，人口模型（由共同主管DZC进行）预测等位基因频率动态发生了巨大变化。在这里，学生将结合联合收割机进化基因组学工具（SNP遗传分析），最先进的人口建模和生态数据来研究Soay绵羊毛色进化动态在过去十年中如何变化。这些发现将进一步阐明遗传变异的进化和维持，并将提供一个框架，以有力地测试人口预测模型。在野生脊椎动物种群中，测试基因频率如何响应实时环境变化而变化通常是不可能的，但短世代时间（雄性和雌性可以在6个月大时繁殖）和长期数据集使圣基尔达索伊羊种群成为例外。自从我们上次发表以来，已有数千只绵羊出生并在其一生中受到监测。基因组学工具的进步意味着SNP基因型数据（约500，000个位点）几乎可用于所有这些。有很少的，如果有的话，类似的机会，在自然环境中研究进化动力学的健身位点。

This project offers the opportunity to study evolutionary genetics as part of the Soay sheep project, one of the most data-rich long-term studies of any vertebrate in the world. There will be opportunities to visit and work on St Kilda, a UNESCO world heritage site.Understanding how genetic and phenotypic variation changes in response to environmental conditions remains one of the great challenges in evolutionary biology. Ten years ago we published a paper in Science (Gratten et al. 2008) showing how allelic variation at the TYRP1 gene underlying a coat colour polymorphism in a wild Soay sheep population has been under natural selection, and how variation at TYRP1 has been maintained. In the following decade, the environment on St Kilda has changed, the population size has increased, and demographic models (conducted by co-supervisor DZC) predict a dramatic change in allele frequency dynamics.Here the student will combine evolutionary genomics tools (SNP genetic profiling), state-of-the-art demographic modelling and ecological data to study how Soay sheep coat colour evolutionary dynamics have changed in the last decade. The findings will shed further light on the evolution and maintenance of genetic variation, and will provide a framework with which to robustly test demographic predictive models. Testing how gene frequencies change in response to real-time environmental change is not often possible in wild vertebrate populations, but the short generation time (males and females can breed at age 6 months) and long-term data set make the St Kilda Soay sheep population an exception. Since our previous publication several thousand sheep have been born and monitored throughout their lifetimes. Advances in genomics tools mean that SNP genotype data (at ~500,000 loci) are available for nearly all of them. There are very few, if any, comparable opportunities to study evolutionary dynamics of fitness loci in the natural environment.