DNA

Student (out of nowhere):  "Mrs. A, I think I have elephant semen in my blood line."
Me:  "What now?"
Student:  "My sister has huge ears and I think that we may have some relation to elephants."
(silence)
Me:  "Wow.  Well, I don't think that elephant semen has anything to do with the genetic make-up of any person, but especially not your sister."
(silence)
Student:  "Yea, maybe not, but her ears are super big."