Vision depends on the protein rhodopsin, which absorbs light in the retina of the eye in a reaction in which one form, metarhodopsin I, is converted to another, metarhodopsin II. The half-life of this reaction in cattle eyes is 600 μs at 37°C but 1 s at 0°C, whereas in frog eyes the same process has a half-life that differs by a factor of only 6 over the same temperature range. Suggest an explanation and speculate on the survival advantages that this difference provides the frog.