Which statement about the molecular clock is true?
A) It requires monophyletic taxa.
B) It requires calibration with independent data, such as from the fossil record.
C) It requires binomial nomenclature.
D) It can only be used if the species diverged less than about 100 million years ago.
E) It can only be used if the species diverged more than about 20 million years ago.

Question

Quizplus · Accepted Answer

The molecular clock is a method for estimating the time of divergence between two species based on the rate of genetic changes. However, this method requires calibration with independent data, such as from the fossil record, to determine the rate of mutation. Therefore, statement B is true. The other statements are false: A) The molecular clock can be used with both monophyletic and paraphyletic taxa, as long as the appropriate genetic data are available. C) Binomial nomenclature is a system for naming species and is not directly relevant to the molecular clock. D) and E) The molecular clock can be used to estimate divergences that occurred millions or even billions of years ago, as long as the appropriate molecular data are available.

Which Statement About the Molecular Clock Is True