The mother is the foundation and the father plants the seed. You are what your father is.
So let's say for argument's sake his father was full Puerto Rican and his Mom, full Irish. He'd be a Puerto Rican with Irish features.
Or lets use Mulattos. Hebrew father and German mother is a Hebrew with German features. This is not something I just made up. This is how the bible does it. Otherwise you get this confusion we have today which breaks down cultures.
You are what your father is, it doesn't matter what you look like.