Adaptive Evolution of Stress Coping Style in Guppies

背景：应激反应允许动物在受到不利环境条件的挑战时保持动态平衡、健康和体能。虽然我们对其中的一些具体途径知道很多，但我们对它们是如何协同工作的知之甚少。例如，当受到环境中的严重威胁--可能是捕食者--的挑战时，神经内分泌通路既会触发行为(如打架或逃跑行为)，也会触发长期的荷尔蒙反应(如循环皮质醇增加)。尽管这些途径需要协调才能保持健康，但根据面临的挑战，不同的特征组合可能是最佳的。这一想法导致了压力反应的行为和内分泌成分应该共同进化的预测，这一假设可以通过观察经历不同压力环境的人群表型分化的遗传基础来检验。具体背景：这个项目将探索在截然不同的捕食和应激状态下进化的特里迪亚孔雀鱼种群的进化。它将主要以实验室为基础，重点关注目前存放在Penryn水生设施中的12个鱼群，这些鱼群来自2017年收集的野生父母。从以前的工作中，我们知道一个群体中的个体在压力反应‘应对方式’上存在差异，个体之间的遗传差异是行为和生理差异的一个重要来源。这种变异为通过自然选择进行进化并在种群之间产生适应性表型差异奠定了基础。目的：利用行为和育种实验、内分泌学和遗传分析(包括数量遗传学和基因组方法)相结合的方法，该项目将检验4个假设：1)种群在行为和内分泌特征上表现出遗传差异，2)行为和内分泌功能是共同进化的，3)分歧是适应性的，不能仅用中性的种群遗传过程(漂移，当代基因流)来解释4)捕食制度是压力反应适应性差异的特定驱动因素。这些目标牢牢植根于进化生物学，成功的申请者将对遗传学产生浓厚的兴趣。将提供定量和群体遗传学/基因组分析所需技能方面的培训。然而，该项目也包含一个很大的行为部分，因此对这一领域的强烈兴趣，加上与动物合作的愿望，也是必不可少的。

Context: Stress responses allow animals to maintain homeostasis, health and fitness when challenged by adverse environmental conditions. Although we know a lot about some of the specific pathways involved, we know less about how they operate together. For instance, when challenged by an acute threat in the environment - perhaps a predator - neuroendocrine pathways trigger both behavioural (e.g. fight or flight behaviours) and longer-term hormonal responses (e.g. increases in circulating cortisol). Although these pathways need to be coordinated to maintain fitness, different trait combinations may be optimal depending on the challenges faced. This idea leads to the prediction that behavioural and endocrine components of stress response should co-evolve, a hypothesis that can be tested by looking at the genetic basis of phenotypic differentiation among populations experiencing different stress environments. Specific background: This project will explore evolution across populations of the Trinidadian guppy that have evolved under very different predation - and so stress - regimes. It will be primarily lab-based, focusing on 12 colonies of fish currently housed in the Penryn aquatic facility that are derived wild parents collected in 2017. From previous work we know that individuals within a population differ in stress response 'coping style' and that that genetic differences among individuals are an important source of behavioural and physiological variation. This variation sets the stage for evolution by natural selection to proceed and generate adaptive phenotypic divergence among populations. Aims: Using a combination of behavioural and breeding experiments, endocrinology and genetic analyses (including both quantitative genetic and genomic approaches) the project will test 4 hypotheses:1) That populations show genetic divergence in behaviours and endocrine traits 2) That behaviour and endocrine function have co-evolved3) That divergence is adaptive and cannot be explained by neutral population genetic processes alone (drift, contemporary gene flow)4) That predation regime is a specific driver of adaptive divergence in stress response.These objectives are firmly rooted in evolutionary biology and the successful applicant will have a strong interest in genetics. Training in skills needed for quantitative and population genetics/genomic analyses will be provided. However, the project also contains a large behavioural component and thus a strong interest in this area, coupled to a desire to work with animals, is also essential.