A Genetic Signature for Positive Selection Is

A genetic signature for positive selection is

A) a gene sequence present in humans and other primates, but with at least one amino acid difference in the encoded protein in humans.
B) a gene that is unique to humans.
C) a gene sequence present in humans and other primates, but with no amino acid sequence differences.
D) a gene that encodes a protein that makes the individual more sexually attractive.
E) a gene that encodes a protein that includes mostly positively charged amino acids.