The role of phylogeny, ecological opportunity, and adaptive radiation in host-parasite interactions: network metrics, host repertoire, and network link prediction

Abstract

Many species-rich ecological communities result from adaptive radiation events. The effects of these explosive speciation events on community assembly remain poorly understood. Here, we explore the well-documented radiations of African cichlid fishes and interactions with their flatworm gill parasites (Cichlidogyrus spp.) including 10529 reported infections and 477 different host-parasite combinations collected through a survey of peer-reviewed literature. We assess the evolutionary, ecological, and morphological parameters on meta-communities partially affected by adaptive radiation evens using network metrics, host repertoire measures, and network link prediction (NLP). The hosts' evolutionary history mostly determined host repertoires. Ecological and evolutionary parameters predicted host-parasite associations, but many interactions remain undetected according to NLP. Parasite meta-communities under host adaptive radiation are more specialised and stable while ecological opportunity and ecological fitting have shaped interactions elsewhere. The cichlid-Cichlidogyrus network is a suitable eco-evolutionary study system but future studies should validate our findings in other radiating host-parasite systems.