An evolutionist can also make predictions that a creationist might never consider. He could even predict that the proteins of fish will be more different still and be right again. Creationists sometimes claim that evolution violates the Second Law of Thermodynamics, which says that any system not receiving inputs of energy tends to become less ordered. But life and the earth receive energy from the sun, so the Second Law isn't violated. We use the sun's energy to produce order ourselves, in the petroleum that powers our factories and in the food that powers our bodies.
Science uses natural causes to explain natural phenomena.
It explains diseases with microbes or physiological disorders, not with evil spirits. Evolution is part and parcel of a scientific understanding of the world. Creationism is not.