The following questions refer to Figure 27.1 below, which is the same as Figure 27.10 in the textbook.
In this 8-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.

Figure 27.1
-Which of these can be inferred from Figure 27.1?
A)Most of the genetic change that permitted adaptation to the new, low-glucose environment occurred toward the conclusion of the experiment.
B)Rates of mitosis increased over the course of the experiment.
C)The highest rate of genetic change occurred during the first quarter of the experiment.
D)After 5,000 generations, the bacteria were 100% more fit than the original, ancestral bacteria.

Question

The following questions refer to Figure 27.1 below, which is the same as Figure 27.10 in the textbook.
In this 8-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.
  
Figure 27.1
-Which of these can be inferred from Figure 27.1?
A)Most of the genetic change that permitted adaptation to the new, low-glucose environment occurred toward the conclusion of the experiment. 
B)Rates of mitosis increased over the course of the experiment. 
C)The highest rate of genetic change occurred during the first quarter of the experiment. 
D)After 5,000 generations, the bacteria were 100% more fit than the original, ancestral bacteria.

Quizplus · Accepted Answer

The statement suggests that the highest rate of genetic change occurred early in the experiment, which is a common pattern in adaptation experiments where initial rapid changes are followed by slower rates of change as the population approaches an adaptive peak.

The Following Questions Refer to Figure 27