Loss of consumers constrains phenotypic evolution in the resulting food web

Evolution Letters

Brendan Locke¹  Matthew A. Barbour²  Jordi Bascompte²  Arezoo Sotoodeh³  Christopher J. Greyson‐Gaito³ 

[1] Department of Biological Sciences Humboldt State University Arcata California 95521;Department of Evolutionary Biology and Environmental Studies University of Zurich Zurich 8057 ZH Switzerland;Department of Zoology University of British Columbia Vancouver BC V6T 1Z4 Canada;

关键词: Adaptive landscape;    community context;    eco‐evolutionary dynamics;    ecological networks;    extinction;    fitness landscape;   

DOI  :  10.1002/evl3.170

来源: DOAJ

【 摘 要 】

Abstract The loss of biodiversity is altering the structure of ecological networks; however, we are currently in a poor position to predict how these altered communities will affect the evolution of remaining populations. Theory on fitness landscapes provides a framework for predicting how selection alters the evolutionary trajectory and adaptive potential of populations, but often treats the network of interacting populations as a “black box.” Here, we integrate ecological networks and fitness landscapes to examine how changes in food‐web structure shape phenotypic evolution. We conducted a field experiment that removed a guild of larval parasitoids that imposed direct and indirect selection pressures on an insect herbivore. We then measured herbivore survival as a function of three key phenotypic traits to estimate directional, quadratic, and correlational selection gradients in each treatment. We used these selection gradients to characterize the slope and curvature of the fitness landscape to understand the direct and indirect effects of consumer loss on phenotypic evolution. We found that the number of traits under directional selection increased with the removal of larval parasitoids, indicating evolution was more constrained toward a specific combination of traits. Similarly, we found that the removal of larval parasitoids altered the curvature of the fitness landscape in such a way that tended to decrease the evolvability of the traits we measured in the next generation. Our results suggest that the loss of trophic interactions can impose greater constraints on phenotypic evolution. This indicates that the simplification of ecological communities may constrain the adaptive potential of remaining populations to future environmental change.

【 授权许可】

Unknown