The figure shows a hypothetical relationship between the growth rates of E. coli at 37 and 42 degrees Celsius. This figure illustrates what type of evolutionary constraint?
A) Physical constraints make it difficult for natural selection to produce E. coli that are successful at 42 degrees.
B) It illustrates the lack of repeatability in evolution.
C) Alleles that are beneficial in one environment may be deleterious in another environment.
D) Changing environments make it impossible for natural selection to act.

Question

The figure shows a hypothetical relationship between the growth rates of E. coli at 37 and 42 degrees Celsius. This figure illustrates what type of evolutionary constraint? 
A) Physical constraints make it difficult for natural selection to produce E. coli that are successful at 42 degrees. 
B) It illustrates the lack of repeatability in evolution. 
C) Alleles that are beneficial in one environment may be deleterious in another environment. 
D) Changing environments make it impossible for natural selection to act.

Quizplus · Accepted Answer

The figure illustrates a trade-off in the growth rates of E. coli at different temperatures. This trade-off suggests that alleles that confer high fitness at one temperature may confer lower fitness at another temperature, indicating that there is a genetic constraint on the evolution of E. coli that prevents it from being successful at both temperatures simultaneously. This is an example of a physiological or environmental constraint on evolution, which is illustrated by the fact that the growth rates are limited by the temperature at which the bacteria are grown. Therefore, choice C is the best answer.

The Figure Shows a Hypothetical Relationship Between the Growth Rates