How Can Gene Duplication Provide an Evolutionary Pathway by Which

Multiple Choice

How can gene duplication provide an evolutionary pathway by which a protein can switch functions without loss of the original function?

A) Gene duplication results in two identical genes that both preserve the same function.
B) A pair of duplicated genes initially perform the same functions, but both genes acquire mutations that change their function.
C) When a gene is duplicated, it rapidly acquires mutations that make it no longer functional.
D) An extra copy of a working gene is formed that can gain a new function without changing the function of the original gene.