American Society of Naturalists

A membership society whose goal is to advance and to diffuse knowledge of organic evolution and other broad biological principles so as to enhance the conceptual unification of the biological sciences.

“Modeling adaptive and non-adaptive responses of populations to environmental change”

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Tim Coulson, Bruce E. Kendall, Julia Barthold, Floriane Plard, Susanne Schindler, Arpat Ozgul, and Jean-Michel Gaillard

New theory is presented to predict how populations will respond to environmental change via adaptation and plasticity

Linkages and feedbacks between ecology and evolution.<br />(Figure prepared by Tim Coulson; ©&nbsp;2017 The&nbsp;University of Chicago Press)
Linkages and feedbacks between ecology and evolution.
(Figure prepared by Tim Coulson; © 2017 The University of Chicago Press)

When the environment changes, populations of wild animals and plants can be affected in a number of ways. In the worst case, they are driven to extinction, while at the other extreme, the change in the environment may have no effect on them at all. A third option is that individuals change in ways that allows them to cope with the new environment. Such change can occur via evolution – a change in the genetic structure of the population – or via something called plasticity, where individuals are able to rapidly alter their phenotypes without any underlying genetic change. Biologists have long been interested in how evolution and plasticity contribute to the ways that populations react to environmental change, but this has been a difficult question to address because of a lack of theory that links plastic and evolutionary change in response to an altered environment. In the paper by Tim Coulson of Oxford University and colleagues in Denmark, France, Switzerland, and the United States, new theory is developed that allows biologists to examine how plasticity and evolution can help populations respond to environmental change. They show that plasticity provides a much faster way of responding to such change than evolution. Evolutionary responses do occur, but they will typically take a few tens of generation. Over this longer time period, plasticity and natural selection (the underpinning of adaptive evolution) can interact to alter the course of evolution. Coulson et al.’s theory offers significant potential to not only understand how populations respond to environmental change, but it also brings together two very disparate bits of existing theory from ecology and evolution: demography and quantitative genetics. Further application of this theory should help explain the intricate interactions between natural selection and plasticity on evolutionary change, providing better insights into the consequences of environmental change on the natural world. Read the Article