Page(s) 81-82 3.4. Natural Selection in the Laboratory Cooper et al. (2001) compared growth rates for 12 E. coli lines across a range of temperatures maintained in the lab for 20,000 generations at 3\deg C. The figure depicts their results. The red line represents the ancestral population, and the blue line represents the population after 20,000 generations. Drag the terms to the blanks in the passage to correctly describe the conclusions you can draw from the graph. A line graph with plotted data showing thermal adaptation in E. coli. The x axis is labeled with temperature in Celsius that ranges from 20 to 40 and the y axis is labeled with maximal rate of division (per hour) that ranges from 0 to 1.2. There are two lines on the graph, one of which represents the ancestral population and the other line represents the population after 20,000 generations. At 20 degrees Celsius the max rate of division for the ancestral population is about 0.25 and 0.3 for the population after 20,000 generations. At about 27 degrees Celsius, the max rate of division for the ancestral population was about 0.5 and 0.58 for the population after 20,000 generations. At about 33 degrees Celsius the max rate of division for the ancestral population was about 0.65 and 0.8 for the population after 20,000 generations. At about 35 degrees Celsius, the max rate of division for the ancestral population was 0.8 and about 0.9 for the population after 20,000 generations. At 37 degrees Celsius the growth rate changes. The max rate of division is about 0.85 for the ancestral population and 1.05 for the population after 20,000 generations. Above 37 degrees Celsius the growth rate begins to decrease for the population after 20,000 generations. The peak growth rate for the ancestral population is about 0.90 and occurs at 40 degrees Celsius. The optimal growth temperature shifted from about – \deg C in the ancestral population to about – \deg C after 20,000 generations. In both populations, bacteria grew more – at temperatures above and below the optimum, suggesting a(n) – between growth performance at the optimal temperature and growth under other thermal conditions. The most likely explanation for this pattern is – , in which genes that have a beneficial effect under one set of conditions have detrimental fitness consequences in a different context.