Effect of host-switching on the eco-evolutionary patterns of parasites

Abstract

Increasing empirical evidence has revealed that host-switching is more common than cospeciation in the history of parasites. Here, we investigated how the intensity of host-switching, mediated by opportunity and compatibility, affects the phylogenetic history and ecology of the parasites. We developed a theoretical model to simulate the evolution of populations of parasites that can explore and colonize new hosts under variable host-switching intensities. Eco-evolutionary patterns (beta diversity/normalized Sackin index) obtained from parasite simulations were compared to nine empirical cases. Our model reproduced the empirical patterns, and such simulations varied in host-switching intensity according to the analysed case. This intensity does not differ among cases of ecto and endoparasites, but it was stronger in local cases when compared to a regional scale. Our results highlight the importance of contact opportunity, and suggest that host-switching intensity mediates the exploration and colonization of new hosts promoting variation in the eco-evolutionary patterns.

Host‐switching events are not always the driver of speciation in social parasites: a case study in Temnothorax (Myrmoxenus) ants (Hymenoptera, Formicidae)

“…(i) The parasite has to establish new associations with the host after transition, and an array of behavioral, physiological, and phenological adaptations are prerequisites to successful adaptations. The hosts' phylogenetic distance determines the parasite's capacity and opportunity to change hosts (D'Bastiani et al., 2023). In our case, each host species, regardless of ground‐ living or arboricolous, belong to a not very deeply diverging monophyletic lineage called T. unifasciatus group (Prebus, 2017) that may not differ substantially from each other in their life cycle characteristics.…”

“…Differential selection and adaptation to different abiotic and biotic environmental factors are often believed to be one of the primary drivers of speciation (Maron et al., 2019; Nosil, 2012). One of the most specific environmental transitions, host‐switching in parasites, has been reported to foster speciation in many host–parasite systems, ascribed to reproductive isolation after establishing a new association with the novel host species (D'Bastiani et al., 2023) and the fact that specific environmental differences may affect genetic traits that trigger speciation processes (Cini et al., 2015; Schluter, 2001). This phenomenon is believed to boost diversity in many specialist herbivores, like gall‐inducing plant parasites (Jones et al., 2022; Tilmon & Tilmon, 2008), and parasites (Johnson et al., 2016; Martins et al., 2021), including social parasites (Buschinger, 2009; Lenoir et al., 2001; Savolainen & Deslippe, 1996).…”

Evolutionary Challenges to Humanity Caused by Uncontrolled Carbon Emissions: The Stockholm Paradigm

“…Most importantly, the authors demonstrated that humans destroyed the natural borders of the biocoenoses, which delineated the natural reservoirs of SARS-CoV-2. In their computational model, Elvira D’Bastiani et al investigated how the intensity of host switching, assumed to depend on the phylogenetic distance between hosts, affects the ecological and evolutionary patterns of parasites under different climatic conditions: “normal”, and changed under anthropogenic influence [ 124 ]. This model allows one to link the intensity of exploration and colonization of new hosts by parasites with mutations and genetic drift.…”