Genomic analysis of fitness-related traits in bighorn sheep

点击翻译按钮获取中文摘要

The aim of my research is to identify the genes that determine trait variation in wild bighorn sheep. To do this, my research group will develop a high density map of the bighorn sheep genome by making extensive use of existing genomic data from closely related domestic sheep and by developing new genomic resources for bighorn sheep. My group will develop and genotype an array of 5,000 single nucleotide polymorphism (SNP) markers for bighorn sheep and use these to map the genes associated with traits such as body weight, horn size, longevity and temperament in two wild populations. In doing this, we will gain a better understanding of the genetic architecture (the number of genes, their action, and their interactive effects) of trait variation. Using this information, we can assess the impact of both artificial and natural selection on genetic variation to develop a broader and more general understanding of the evolutionary impact of human activity on wildlife. In one population, we will study the impact of 40 years of trophy hunting on genetic variation for horn size and body weight. We will test the hypothesis that trophy hunting has adversely affected genetic variation for horn growth, therefore leading to the evolution of rams with shorter horns by changing the frequency of horn growth alleles in the population. In a second population, we will test the hypothesis that a "genetic rescue", accomplished by the deliberate introduction of new migrants to an isolated population, was caused by the introgression of new genetic variants carried by the migrants which were subsequently favoured by natural selection. The outcomes of this work will be important both for our basic understanding of the nature of phenotypic variation in wildlife (e.g. how much of the variation that we observe is due to a few genes of large effect?) as well as for more specific questions related to the evolutionary consequences of human activity (e.g. does harvesting adversely affect the gene pool of the target population?).