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Updated: Aug 8, 2026
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Published on: May 7, 2016
Experimental evidence that predation promotes divergence in adaptive radiation
Patrik Nosil1, Bernard J Crespi
1Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada V5A 1S6. pnosila@sfu.ca
Summary
Predation can drive adaptive radiation, leading to diverse traits in species like Timema stick insects. This study shows predator-driven selection strongly correlates with observed trait divergence in nature.
Area of Science:
- Evolutionary Biology
- Ecology
- Behavioral Ecology
Background:
- Adaptive radiation drives ecological and phenotypic diversity in multiplying lineages.
- Resource competition is a primary inferred driver of phenotypic divergence.
- The role of predation in adaptive radiation remains debated.
Purpose of the Study:
- To investigate if divergent selection from visual predators drives adaptive radiation.
- To examine the role of predation in phenotypic divergence using Timema stick insects.
- To correlate selection strength with population divergence under predation pressure.
Main Methods:
- Studied Timema stick insect ecotypes differing in host-plant use.
- Quantified phenotypic traits including color, pattern, size, and shape.
- Conducted manipulative field experiments to estimate divergent selection in the presence of predators.
Main Results:
- Timema ecotypes showed early-stage adaptive radiation criteria and phenotypic differences.
- Divergent selection on traits was strongly correlated with population divergence.
- This correlation was significant specifically when predation was present.
Conclusions:
- Divergent selection from visual predators can drive adaptive radiation.
- Both resource competition and predation are likely common mechanisms of adaptive radiation.
- Predation plays a significant role in shaping phenotypic diversity during adaptive radiation.
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