During an experiment, if you purposely change the temperature to test a hypothesis, the temperature is called the a. manipulated variable b. responding variable c. hypothetical variable d. dependent variable

B. Clams and squid have been evolving separately for a shorter time than clams and snails.

Explanation:

A molecular clock is a genetic tool often used in Evolutionary Biology which states that the genetic material and proteins evolve over time at a relatively constant rate. Therefore, the differences in their genome depend on the common ancestor both species share.

In this case, clams and squid are more closely related than clams and snails. Therefore, they have been evolving separately for a shorter time than clams and snails.