Cloning -- we've seen it in movies like 'Moon,' 'The 6th Day,' and 'Star Wars: Attack of the Clones.' Of course, don't forget rad TV shows like 'Orphan Black.' But how about the real world? Science can clone animals, so why haven't we seen cloned humans yet? Biology lecturer Joanne Manaster fills us in on why real-life human cloning hasn't happened yet...or has it?