Lenski and Travisano compared what happened to the fitness of cells in 12 replicate lines of E. coli. According to the graph shown, which of the following statements is true?

Question

Quizplus · Accepted Answer

The graph shows a general trend of increasing fitness in all 12 lines of E. coli, but there is variation in the degree of fitness increase among the lines. This suggests that natural selection is acting on these populations, and they are evolving different adaptations to their environment. Option A is incorrect because fitness does not appear to decrease in any of the lines. Option B is incorrect because there is no evidence that all of the lines reached their maximum fitness and stopped evolving. Option D is incorrect because the graph clearly shows that evolution by natural selection is occurring in these populations.

Lenski and Travisano Compared What Happened to the Fitness of Cells