Melanin-based colouration and host-parasite interactions under global change

The role of parasites in shaping melanin-based colour polymorphism, and the consequences of colour polymorphism for disease resistance, remain debated. Here we review recent evidence of the links between melanin-based colouration and the behavioural and immunological defences of vertebrates against their parasites. First we propose that (1) differences between colour morphs can result in variable exposure to parasites, either directly (certain colours might be more or less attractive to parasites) or indirectly (variations in behaviour and encounter probability). Once infected, we propose that (2) immune variation between differently coloured individuals might result in different abilities to cope with parasite infection. We then discuss (3) how these different abilities could translate in variable sexual and natural selection in environments varying in parasite pressure. Finally, we address (4) the potential role of parasites in the maintenance of melanin-based colouration polymorphism...

寄生虫在基于黑色素的体色多态性（melanin-based colour polymorphism）形成过程中所发挥的作用，以及体色多态性对疾病抗性产生的影响，迄今仍存在诸多争议。本文综述了近年来关于基于黑色素的体色与脊椎动物针对寄生虫的行为防御及免疫防御之间关联的研究证据。首先，我们提出如下观点：其一，不同体色形态的个体与寄生虫的接触暴露程度存在差异，这种差异可通过两种途径产生——直接途径（即特定体色对寄生虫的吸引力存在强弱差异），以及间接途径（即行为差异会改变个体与寄生虫的遭遇概率）。其二，一旦感染寄生虫，体色各异的个体其免疫功能存在差异，这可能导致它们应对寄生虫感染的能力各不相同。其三，我们探讨了在寄生虫压力各异的环境中，上述免疫能力的差异如何转化为差异化的性选择与自然选择。最后，我们探讨了寄生虫在维持基于黑色素的体色多态性方面的潜在作用……