Every cell of the body has the entire genetic code. So why don't we have fingernails on our elbows, or teeth on our forehead? Because "expression" of genes is controlled at each step of the way. Each change of tissue, organ, etc., required that "switches" be turned on or off. It is amazing enough that genes can direct formation of each part of the body, but it is just plain awesome that at each and every minute stage of development the "expression" of those genes must be carefully, precisely controlled.
God is an awesome Creator!
Dr. Louis Bounoure, a prominent Swiss scientist of the past, said, "Evolution is a Fairy Tale for Grownups."