How might this change affect the structure and function of the protein?

Explanation:

Three-dimensional folding of a protein is due to interactions among the R groups of the amino acids. Cysteine has a sulfhydryl group, which may form a disulfide bridge with another part of the polypeptide chain. Valine has no sulfhydryl group and is nonpolar, which will affect how the polypeptide will fold.

i think the miocene epoch spans the time from 23 million to 12 million years ago.