A study of an aphid pest and its predators shows that when climate change hits, consequent shifts in food webs can combine with rapid evolution to buffer the adverse effects of warming.
Jason Harmon of the University of Wisconsin, Madison, and colleagues conducted field experiments with pea aphids feeding on alfalfa crops to determine how the herbivorous pest would respond to high temperatures in the presence of different predator ladybird species. When aphid population growth was dampened by heat shock — induced by plastic-wrapping the insects' cages to raise mid-day temperatures 5 °C — one ladybird species left the sparser populations alone, whereas the other stayed on the hunt, further culling the pests. But warming also gave an advantage to a strain of aphids carrying heat-tolerant microbial symbionts, enabling rapid evolution, the researchers found. Using a mathematical model, the team shows that ladybird predators will act alongside evolution to set the size of future aphid populations, but will not influence how quickly heat tolerance evolves.
Though ecological and evolutionary responses to change are complex, this study shows it is possible to account for such factors in predicting how species are likely to fare in a warmer world.
Rights and permissions
About this article
Cite this article
Barnett, A. Evolutionary escape. Nature Clim Change 1, 42 (2009). https://doi.org/10.1038/climate.2009.26
Published:
Issue Date:
DOI: https://doi.org/10.1038/climate.2009.26
