title: Can environmental change affect host/parasite-mediated speciation?
abstract: Parasitism can be a driver of species divergence and thereby significantly alter species formation processes. While we still need to better understand how parasite-mediated speciation functions, it is even less clear how this process is affected by environmental change. Both rapid and gradual changes of the environment can modify host immune responses, parasite virulence and the specificity of their interactions. They will thereby change host-parasite evolutionary trajectories and the potential for speciation in both hosts and parasites. Here, we summarise mechanisms of host-parasite interactions affecting speciation and subsequently consider their susceptibility to environmental changes. We mainly focus on the effects of temperature change and nutrient input to ecosystems as they are major environmental stressors. There is evidence for both disruptive and accelerating effects of those pressures on speciation that seem to be context-dependent. A prerequisite for parasite-driven host speciation is that parasites significantly alter the host's Darwinian fitness. This can rapidly lead to divergent selection and genetic adaptation; however, it is likely preceded by more short-term plastic and transgenerational effects. Here, we also consider how these first responses and their susceptibility to environmental changes could lead to alterations of the species formation process and may provide alternative pathways to speciation.
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom. Electronic address: f.s.brunner@qmul.ac.uk.
authors.forename: Franziska S
authors.initials: FS
authors.lastname: Brunner
authors.affiliation: School of Biological and Chemical Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, United Kingdom.
authors.forename: Christophe
authors.initials: C
authors.lastname: Eizaguirre
mesh_terms: D000818:Animals; D057231:Climate Change; D017753:Ecosystem; D049810:Genetic Speciation; D010273:Parasitic Diseases, Animal / Q000235:genetics*
keywords: Environmental change; Host/parasite-mediated speciation; Host–parasite interaction; Phenotypic plasticity; Speciation