Question

A scientist is trying to determine the relationship between clams, snails, and squid. When she generates a molecular clock, she is surprised to see that clams and squid are more closely related than clams and snails. Which did the molecular clock data show?

Answer 1

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

Answer 2

Molecular clocks use the rate of mutation for biomolecules to work out when two life forms diverged during their development. If the molecular clock shows clams are more closely related to squid than snails, this suggests that the divergence between clams and squid occurred more recently in prehistory than the divergence of clams and snails.