Plants' Adaptation to Weather Outpaced by Climate Change

The native prairie legume partridge pea, Chamaecrista fasciculata. © Science

Climate change may outpace certain plants' ability to adjust to warmer conditions, a new study published by J. R. Etterson and R. G. Shaw from the University of Minnesota in the 5 October 2001 issue of the journal Science suggests.

Plants have typically responded to climate change by adapting or migrating to more comfortable regions. As habitats become increasingly fragmented, adaptation may become even more important. Adaptive evolution can be slowed down when various beneficial traits compete with each other to be expressed, and therefore are slower to be inherited together than they would be separately. For example, growing more leaves and growing thicker leaves may both help a plant adapt to climate change, but the "antagonistic" genetic relationships between these traits may prolong the amount of time it takes for plants to do both at once.

Julie R. Etterson and Ruth G. Shaw studied several populations of a common prairie legume, and calculated the number of generations necessary for the type of adaptive changes that would help plants cope with climate warming. They found that adaptation would occur more slowly than the rate of climate change predicted by global climate models.

-- Kathy Wren