To answer this question, you need to look back at the evolution of the globin gene family in humans, which is shown in Figure 8.7.

Throughout the evolution of this gene family, mutations have occurred that have resulted in globin polypeptides with similar but significantly different amino acid sequences. If you look at the multiple-sequence alignment in Figure 23.10, you can make logical guesses regarding the timing of mutations, based on a comparison of the amino acid sequences of the globin polypeptides. What is/are the most probable time(s) that mutations occurred to produce the following amino acid differences?

Figure 8.7:

Figure 23.10:

A. Val-111 and Cys-111 B. Met-112 and Leu-112 C. Ser-141, Asn-141, Ile-141, and Thr-141