George Gilchrist’s fly lab at the College of William and Mary studied adaptation to climate on ecological time scales. Now a major question is whether evolution can rescue populations in demographic decline caused by rapid climate change. The answer depends in part on the variance in fitness, which determines the rate of adaptation. The variance is fitness is not necessarily static, but can increase or decrease depending on the rate of climate change and the niche breadth of organisms. These are empirical parameters that must be measured in the field. In this study, we used a space-for-time substitution with five populations of the perennial herb Mimulus cardinalis to measure how the mean and variance in fitness change as populations move farther from their climatic optimum. If the variance in fitness increases with climatic distance, a proxy for future climate change, then evolutionary rescue may be easier than predicted by models assuming constant variance. Conversely, if variance in fitness decreases with climatic distance, then evolutionary rescue should be less likely. This talk is dedicated in honor of Dr. G’s contributions to undergraduate teaching and research.