Predator coexistence through emergent fitness equalization
- The competitive exclusion principle is one of the oldest ideas in ecology and states that without additional self-limitation two predators cannot coexist on a single prey. The search for mechanisms allowing coexistence despite this has identified niche differentiation between predators as crucial: without this, coexistence requires the predators to have exactly the same R* values, which is considered impossible. However, this reasoning misses a critical point: predators' R* values are not static properties, but affected by defensive traits of their prey, which in turn can adapt in response to changes in predator densities. Here I show that this feedback between defense and predator dynamics enables stable predator coexistence without ecological niche differentiation. Instead, the mechanism driving coexistence is that prey adaptation causes defense to converge to the value where both predators have equal R* values ("fitness equalization"). This result is highly general, independent of specific model details, and applies to both rapidThe competitive exclusion principle is one of the oldest ideas in ecology and states that without additional self-limitation two predators cannot coexist on a single prey. The search for mechanisms allowing coexistence despite this has identified niche differentiation between predators as crucial: without this, coexistence requires the predators to have exactly the same R* values, which is considered impossible. However, this reasoning misses a critical point: predators' R* values are not static properties, but affected by defensive traits of their prey, which in turn can adapt in response to changes in predator densities. Here I show that this feedback between defense and predator dynamics enables stable predator coexistence without ecological niche differentiation. Instead, the mechanism driving coexistence is that prey adaptation causes defense to converge to the value where both predators have equal R* values ("fitness equalization"). This result is highly general, independent of specific model details, and applies to both rapid defense evolution and inducible defenses. It demonstrates the importance of considering long-standing ecological questions from an eco-evolutionary viewpoint, and showcases how the effects of adaptation can cascade through communities, driving diversity on higher trophic levels. These insights offer an important new perspective on coexistence theory.…
Author details: | Ellen van VelzenORCiDGND |
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DOI: | https://doi.org/10.1002/ecy.2995 |
ISSN: | 0012-9658 |
ISSN: | 1939-9170 |
Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/32002995 |
Title of parent work (English): | Ecology : a publication of the Ecological Society of America |
Publisher: | Wiley |
Place of publishing: | Hoboken |
Publication type: | Article |
Language: | English |
Date of first publication: | 2020/01/31 |
Publication year: | 2020 |
Release date: | 2023/01/16 |
Tag: | coexistence; competition; competitive exclusion; defense; dynamics; eco-evolutionary feedbacks; emergent facilitation; predator; prey |
Volume: | 101 |
Issue: | 5 |
Article number: | e02995 |
Number of pages: | 10 |
Funding institution: | German Science Foundation (DFG)German Research Foundation (DFG); [GA401/26-1] |
Organizational units: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Biochemie und Biologie |
DDC classification: | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
Peer review: | Referiert |
Publishing method: | Open Access / Hybrid Open-Access |
License (German): | CC-BY - Namensnennung 4.0 International |