such as "Introduction", "Conclusion"..etc
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
"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 her colleague's recent
thermodynamic model, forthcoming in the October issue of The American
Naturalist, argues against such compensation.
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,
Source: University of Chicago Press Journals. October 2006.
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