Ebony and Ivory

One day the wife of the tribe's chief gives birth to a white child.
The members of the tribe are shocked, and the chief pulls the professor
aside and says, "Look here! You're the only white man we've ever seen and
this woman gave birth to a white child. It doesn't take a genius to figure
out what happened!"
The professor replied, "No, Chief. You're mistaken. What you have here is a
natural occurrence... what we in the civilized world call an albino! Look
at that field over there. All of the sheep are white except for one black
one. Nature does this on occasion."
The chief was silent for a moment, and then said, "Tell you what. You don't
say anything more about the sheep and I won't say anything more about the
baby."