An article in a scientific publication suggests that seven different amino acids and 11 types of nucleobases formed in ice when ammonia and cyanide were left in a freezer from 1972 â `` 1997 . An article in Discover Magazine points to research by the Miller group indicating the formation of seven different amino acids and 11 types of nucleobases in ice when ammonia and cyanide were left in a freezer from 1972 â `` 1997 .