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?
Clams and squid have been evolving separately for a longer time than clams and snails.
Clams and squid have been evolving separately for a shorter time than clams and snails.
Clams and snails have more in common genetically than clams and squid.
Clams and snails are more similar in related structures than clams and squids.

Answer 1

Answer:

The correct answer is the second statement.

Explanation:

The molecular clock refers to a procedure in molecular evolution that associate the time of divergence between the two species with the number of molecular differences determined between the sequences of DNA or proteins.  

The more genetically associated, the shorter will be the separation time between the two species. Due to this, as clams and squid are more closely associated it can be concluded that these species look more genetically identical, and have evolved distinctly for a brief time duration in comparison to the clams and snails.  

Answer 2

A scientist is trying to determine the relationship between clams, snails, and squid. When she generates a molecular clock, she is surprised to see thatclams and squid are more closely related than clams and snails. The molecular clock data show that (A) Clams and squid have been evolving separately for a longer time than clams and snails.