Human and sperm whale myoglobin have very similar primary structures. Which of the following statements are correct?

A. The two proteins are very likely related evolutionarily.

B. The differences in the sequences in many instances represent a conservative change (such as L for I).

C. The differences in the sequences in many instances represent a non conservative change (such as D for A).

D. There is no correlation between the two proteins, since they originate from very different specie

A. The two proteins are very likely related evolutionarily.

B. The differences in the sequences in many instances represent a conservative change (such as L for I).

Explanation:

A. Humans and sperm whales are vertebrates and mammals, this implies that they have a common ancestor a long time ago, which makes them evolutionary related.

B. Conservation indicates that a sequence has been maintained by natural selection. This means that protein structure is not exactly the same but is quite similar.

Options C and D, contradict the above explanation, and they make no sense because sperm whales and humans share a common ancestor (mya).