Actually scientists have been making new discoveries that what we call "race" is composed of more differences than mere skin color alone. When we classify people into Caucasoid, Negroid, and Mongoloid, common genetic ancestry has a correlation with shared cognitive patterns, habits, tendencies to react to certain stimuli a certain way, etc. (Too lazy to source so anyone can feel free to assume this is a fabrication.) I see what you are saying, but in that case interracial could be two people with different ear wax, and i feel like these differences do not portray multiple races, but one with many variations