In This Eight-Year Experiment, 12 Populations of E

Multiple Choice

In this eight-year experiment, 12 populations of E. coli, each begun from a single cell, were grown in low-glucose conditions for 20,000 generations. Each culture was introduced to fresh growth medium every 24 hours. Occasionally, samples were removed from the populations, and their fitness in low-glucose conditions was tested against that of members sampled from the ancestral (common ancestor) E. coli population.
-Imagine that after generation 20,000, the experimental cells were grown in high-glucose conditions for 20,000 generations (using the same transfer process described) . Refer to the y-axis on the graph and predict the fitness of the new lines when tested in low- and high-glucose conditions.

A) low: 1.0; high: 1.0
B) low: 1.6; high: 1.6
C) low: 1.0; high: 1.6
D) low: 1.6; high: 1.0