Climate change is an escalating threat facing populations around the globe, necessitating a robust understanding of the ecological and evolutionary mechanisms dictating population responses. However, populations respond to climate change not in isolation but rather in the context of their existing ranges. In particular, spatial population structure within a range (e.g., trait clines, starkness of range edges, etc.) likely interacts with other ecological and evolutionary processes during climate-induced range shifts. Here, we use an individual-based model to explore the interacting roles of several such factors in range shift dynamics. We show that increased spatial population structure (driven primarily by a steeper environmental gradient) severely increases a population’s extinction risk. Further, we show that while evolution of heightened dispersal during range shifts can aid populations in tracking changing conditions, it can also interact negatively with adaptation to the environmental gradient, leading to reduced fitness and contributing to the increased extinction risk observed in populations structured along steep environmental gradients. Our results demonstrate that the effect of dispersal evolution on range-shifting populations is dependent on environmental context and that spatial population structure can substantially increase extinction risk in range shifts.
Bibliographical noteFunding Information:
We thank Lauren Shoemaker, Lauren Sullivan, and members of the Theory Under Construction group at the University of Minnesota for providing thoughtful comments on the manuscript. C.W.-L. was supported by start-up funds from the University of Minnesota (to A.K.S.), and A.K.S. was supported in part by funding from the National Science Foundation. We acknowledge the Minnesota Supercomputing Institute at the University of Minnesota (http://www.msi.umn.edu) for providing resources that contributed to the results reported within this article. Finally, we thank two anonymous reviewers for comments that greatly improved the manuscript.
© 2019 by The University of Chicago.
- Dispersal evolution
- Individual-based model
- Range shifts
- Rapid evolution
PubMed: MeSH publication types
- Journal Article
- Research Support, Non-U.S. Gov't
- Research Support, U.S. Gov't, Non-P.H.S.