Tactics of acclimation: morphological changes of sponges in an unpredictable environment.

Reciprocal transplants of genetically identical fragments of intertidal sponges between environments of high and low wave action exhibit great variability in the timing of their responses to environmental change. Sponges quickly begin production of stiffer and stronger tissues in high wave energy environments but delay formation of new, weak tissues in calm habitats. This may be due to the risks of forming wave-intolerant tissue in a temporally variable, unpredictable environment. These results suggest that the evolution of acclimatory control is linked to environmental predictability and concomitantly to risks of acclimatory errors.