Beneficial Acclimation Hypothesis - Experimental Tests

Experimental Tests

The majority of tests of the Beneficial Adaptation Hypothesis have, following Krogh's Principle, centered on the model organisms Drosophila melanogaster and Escherichia coli. More specifically, experimental tests have centered on easily-measured temperature adaptation (although other systems have been studied; see ). Of the several experimental tests of the Beneficial Acclimation Hypothesis, most have rejected it as a universal rule (see reviews ).

Initial experiments by Leroi et al., the first scientists to address this problem, tested only the Beneficial Acclimation Hypothesis and not the subsequent hypotheses developed by Huey et al. Colonies of E. coli were acclimated for seven generations in two different temperature conditions: 32 °C and 41.5 °C. Colonies were then competed against each other at those temperatures. He found that, agreeing with the Beneficial Acclimation Hypothesis, colonies acclimated at 32 °C competed better at 32 °C. However, at 41.5 °C, colonies acclimated at 32 °C competed better as well. This led to the authors’ rejection of the generality of beneficial acclimation. Huey et al. examined four previously-conducted studies, applying the five competing hypotheses, and found that none of the results of the studies could be entirely explained by beneficial acclimation. Instead, a combination of hypotheses were required to explain the observed patterns of acclimation.