Study of spiders shows species may be able to adapt to global warming
The Yale research examined a well-studied grassland food web, made up of a predatory spider, its grasshopper prey, and the plants grasshoppers fed on. The spider's predatory behaviour is known to be temperature-sensitive, decreasing with increased temperatures. Researchers had expected higher temperatures to stop the spiders preying on grasshoppers, leading to more plants being eaten.
However, in the study, spider populations from warmer areas tolerated higher temperature ranges better than the populations from cooler areas and continued to control the grasshopper popualtion. This suggests they can adapt to local conditions and maintain their vital role in the community despite increased temperatures.
'Species are almost certainly adapting to the climate change Earth has experienced during the past century,' study author Dr Brandon Barton told the Ecologist. 'My results show that species have the capacity to adapt to a range of temperatures, similar to those predicted by climate change models, and that a species' role in the community can be conserved by this adaptation.'
Many similar experiments expose organisms to short-term, sudden increases in temperature, which does not allow for long-term gradual processes like climate change. Barton's work overcomes these limitations by looking at populations along a natural temperature gradient to see if long-term changes in temperature would affect small-scale food webs. He sampled spiders at sites from a 500km, north-south axis, along the east coast of the United States, where temperature varied by 4.8C.