The performances of organisms depend greatly on temperature, with most performances being maximized within a narrow thermal range. This phenomenon stems from effects of temperature on cellular structures, such as enzymes and membranes. Nevertheless, thermal sensitivities vary among genotypes, indicating the capacity for adaptation of cellular structures to local environments. The concept of a performance curve enables biologists to quantify and compare thermal optima and thermal breadths of performance. Optimality models predict that the thermal optimum should evolve to match the mean body temperature of an organism. The evolution of the thermal breadth depends on whether performance contributes to survivorship or fecundity. Studies of various performances provide mixed support for the predictions of optimality models. The failure of these models could reflect an overly simplistic view of the tradeoffs that shape performance curves. Moreover, quantitative genetic and allelic models indicate that insufficient genetic variance or extensive gene flow prevents adaptation to local thermal environments.
Oxford Scholarship Online requires a subscription or purchase to access the full text of books within the service. Public users can however freely search the site and view the abstracts and keywords for each book and chapter.
If you think you should have access to this title, please contact your librarian.