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Closing the gap in the Janzen-Connell hypothesis: What determines pathogen diversity?
Marjolein Bruijning1,2, C Jessica E Metcalf2, Marco D Visser2,3
1Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.
Ecology Letters
|October 3, 2023
Summary
The Janzen-Connell hypothesis explains tropical tree diversity through specialized enemies. This study explores the evolution of these interactions, showing how host-pathogen coevolution can maintain high species diversity.
Area of Science:
- Ecology
- Evolutionary Biology
- Epidemiology
Background:
- Tropical forests exhibit high tree diversity, a long-standing ecological puzzle.
- The Janzen-Connell hypothesis posits that specialized enemies stabilize tree species coexistence.
- Previous theoretical studies often assumed pathogen presence, neglecting pathogen coexistence requirements.
Purpose of the Study:
- To investigate the evolutionary conditions enabling Janzen-Connell effects.
- To explore the interplay between host-pathogen ecology and evolution in maintaining diversity.
- To provide a robust theoretical foundation for the Janzen-Connell hypothesis.
Main Methods:
- Utilized five theoretical frameworks, integrating community ecology, evolutionary biology, and epidemiology.
- Employed Lotka-Volterra competition models, extended to include single- and multi-pathogen dynamics.
- Developed a coevolutionary model incorporating host and pathogen evolution.
Main Results:
- Demonstrated that host-pathogen coevolution can lead to highly diverse tropical forest systems.
- Unpacked underlying assumptions of the Janzen-Connell hypothesis.
- Established theoretical bounds for pathogen and host ecology and evolution.
Conclusions:
- Host-pathogen coevolution is a crucial factor in the evolution of Janzen-Connell effects.
- A comprehensive theoretical basis strengthens the understanding of diversity maintenance in tropical forests.
- These insights are vital for conserving threatened tropical ecosystems.
Keywords:
Janzen-Connell hypothesisSIS modeladaptive dynamicshost-parasite coevolutionmodern coexistence theoryMore Related Videos
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