Hotter Is Better For Insects
- Hotter Is Better For Insects
by Staff Writers
Seattle WA (SPX) Oct 03, 2006
Organisms have been able to adapt to environments ranging from cold
polar oceans to hot thermal vents. However, University of Washington
researchers have discovered a limit to the powerful forces of
natural selection, at least when it comes to the adaptation of
insects to cold temperatures.
"For thermodynamic reasons, cold temperatures present a challenging
problem for ectothermic [cold-blooded] organisms because they slow
biological processes, thus reducing rates of movement, feeding, and
population growth," explains author M. R. Frazier.
Many researchers believe that biochemical adaptations can eventually
compensate for the effects of low body temperatures, but Frazier and
his colleague's recent thermodynamic model, forthcoming in the
October issue of The American Naturalist, argues against such
To address this controversy, the researchers conducted a comparative
analysis of published data on the thermal dependence of population
growth rate for 65 insect species. They found that insects adapted
to cold environments have slower maximum population growth rates
than those adapted to warm environments, despite their long
evolutionary history in such environments.
"At least with respect to insect population growth rates," says
Frazier, "our data suggest that hotter is better. We see little
evidence of evolutionary compensation."
This research suggests that adaptation to warmer or to colder
temperature inevitably alters the population dynamics of insects, a
result that has important consequences for agriculture, public
health, and conservation.
University of Washington
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