Endemism and invasion in the speciation and polymorphism of snails and slugs

入侵的蜗牛和蛞蝓正在造成世界范围的问题，既对农作物造成直接损害，又作为农场动物疾病的中间媒介。然而，蜗牛和蛞蝓很难识别，我们也不知道是什么影响了它们的物种形成。因此，本项目的目的是研究蜗牛的物种形成过程，使用来自英国另一个目标国家的适当代表物种。具体来说，如果最终目的是了解外部环境和遗传学如何相互作用以形成适应性变异，那么必须准确定义外部表型。学生将开发方法来定义和量化在不同的空间尺度上的个体和种群的多态性，同时考虑到鸟类捕食者的视觉敏锐度和更一般的环境。高斯混合模型（Mixing in R）将用于客观地计算变体的数量，并使用“仅可察觉的差异”来检查鸟类和人类的可辨别性。虽然大部分工作将以实验室为基础，并伴随着生物信息学要素，但实地收集将是一个必要的组成部分，包括可能的国外实地工作。

Invasive snails and slugs are causing worldwide problems, both in terms of direct damage to crops, and as intermediate vectors for diseases of farm animals. Yet, snails and slugs are difficult to identify and we have little idea of what influences their speciation. The aim of this project, therefore, will be to study the process of speciation in snails, using appropriate representative species from the UK one other target country. Specifically, if the ultimate aim is to understand how the external environment and genetics interact to shape adaptive variation, then the outward phenotype must be defined accurately. The student will develop methods to define and quantify the polymorphism in individuals and in populations at different spatial scales, taking into account the visual acuity of bird predators and the more general environment. Gaussian mixture modelling (Mclust in R) will be used to characterise the number of morphs objectively, and examine discriminability by birds and humans using "just noticeable differences". The output will then be used to inform subsequent objectives.Although much of the work will be lab-based, with a concomitant bioinformatics element, field collection will be a necessary component, including probable foreign field work.