Lenski and Travisano Compared What Happened to the Fitness of Cells

Multiple Choice

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?

A) Fitness increased in some of the lines and decreased in other lines.
B) Fitness increased initially, but after about 3,000 generations all of the lines reached their maximum fitness and quit evolving.
C) Fitness increased in every line, but to a different degree in each line.
D) Evolution by natural selection cannot be predicted at any level.