Parasite extinction and colonisation and the evolution of parasite communities: a simulation study

Area of Science:

• Evolutionary biology
• Parasitology
• Ecology

Background:

• Comparative analyses often investigate how host ecological traits influence parasite community richness.
• Understanding the evolutionary processes shaping these relationships is crucial for ecological and evolutionary studies.

Purpose of the Study:

• To determine the evolutionary factors affecting the detectability of host ecological influences on parasite community richness.
• To assess the interplay between phylogenetic effects and ecological effects in host-parasite systems.

Main Methods:

• A mathematical model was developed to simulate host phylogenies and parasite community evolution over time.
• Parasite species gain and loss were modeled as stochastic events influenced by host ecological characteristics.
• Simulations varied the strength of host ecology effects, parasite gain/loss probabilities, and rates of ecological change.

Main Results:

• Phylogenetic effects, representing the inheritance of parasite species, frequently obscure the impact of host ecological characteristics.
• Ecological effects are more detectable when they are strong, parasite gain/loss probabilities are high, or host traits change significantly during speciation.
• The shape of the host phylogenetic tree did not influence the detectability of ecological effects.

Conclusions:

• Parasite community composition often reflects host ancestry, making it difficult to detect the influence of host ecology.
• Evolutionary processes, particularly phylogenetic inertia, present significant challenges in identifying ecological drivers of parasite diversity.