The Evolutionary Response to Unpredictable Environmental Change

Date Published: November 24, 2014

Source: Proceedings of the National Academy of Sciences (PNAS)

Institutions Involved: Department of the Interior Southeast Climate Science Center at North Carolina State University, Department of Biology at Washington University in St. Louis, Centre for Ecological and Evolutionary Studies at the University of Groningen, Centre for Biodiversity Dynamics at Norwegian University of Science and Technology, Department of Ecology, Evolution and Environmental Biology at Columbia University.

Summary:

Variability is becoming more frequent and unpredictable in today’s environment. As a result of this variation in environmental conditions, there is a pressing need for species to cope with and adapt to this phenomenon. Understanding how organisms adapt to changes in their environments is a pivotal idea in evolution and ecology. Evolutionary responses to ecological parameters, such as ambient temperatures or precipitation, can help determine species’ adaptation to environmental change. In a study conducted by Carlos A. Botero, Franz J. Weissing, Jonathan Wright, and Dustin R. Rubenstein, these issues are addressed and analyzed. They study the changes in the predictability of environmental variation that may ultimately affect population feasibility. These biologists develop a model that predicts evolutionary responses to fluctuating environmental conditions and explores the potential consequences of altered environmental cycles. The model indicates that there remains a possibility that fairly large environmental changes can lead to extinction. The model also shows that “parameter space determined by different combinations of predictability and timescale of environmental variation is partitioned into distinct regions where a single mode of response (reversible phenotypic plasticity, irreversible phenotypic plasticity, bet-hedging, or adaptive tracking) has a clear selective advantage over all others”. Furthermore, the model demonstrates that despite evolutionary accommodation, most changes in the environment involve transitions between regions. This, ultimately, can result in rapid population collapse and even extinction. Finally, the model shows that different genetic backgrounds can influence the probability of extinction during such transitions. These insights essentially portray the value of evolutionary thinking in the study of global environmental change. Intrinsically, through evolutionary simulations, these biologists show that adaptive responses consistently evolve under and heavily depend on the different timescales and predictabilities of environmental variation. “Specifically, the potential for adaption to changes in the predictability or timescale of environmental change appears to depend more on the location of parameter space that populations are moving into than on the magnitude of the change itself.” In conclusion, this study helps us expand our understanding of how populations and species may respond to environmental changes and challenges.

Citation:

Botero, C.A., F.J. Weissing, J. Wright, and D.R. Rubenstein. 2014. Evolutionary Tipping Points in the Capacity to Adapt to Environmental Change. Proceedings of the National Academy of Sciences 112:184-189.