When researchers use a molecular clock what are they measuring?

They are measuring the time that two species have been evolving independently.

A molecular clock is a method that is used by scientists to estimate the time that two species evolve separately using the knowledge of the DNA differences. To carry out this method, scientists use (i) an estimate of the number of genetic mutations that occur between two closely related species and (ii) the average genetic mutation rate to estimate the time in prehistory when the two species split.

answer; i believe the answer is (polygenic inheritance;

the atmospheric gas that forms a mild acid when dissolved in water is called carbon dioxide. the correct answer is a. 2.) chemical weathering would cause an inscription on a marble headstone to become harder and harder to read over time.