Biologists are studying two species whose DNA is known to differ by 10%. Which information would be least important in calibrating a molecular clock to determine how rapidly evolution has proceeded with these two species?
A) the fossil record of these two species
B) a geological event that separated the species at a particular time
C) the function of each of these regions of DNA
D) the time of divergence of closely related species

Question

Quizplus · Accepted Answer

The function of each region of DNA would not be relevant in determining the rate of evolution between the two species, as the molecular clock would be based on the overall genetic differences between the two species rather than the specific functions of individual regions. The fossil record and the time of divergence of closely related species would provide important context for calibrating the molecular clock, while a geological event that separated the species at a particular time could help to establish a fixed point in time for the analysis.

Biologists Are Studying Two Species Whose DNA Is Known to Differ