How Tortoiseshell Cats Show the Limits of Cloning

When we first discovered the structure of DNA, it looked like all of life's mysteries were at our fingertips. We could control life and death! But soon enough, we started to run up against the limits of our awesome power over genetics — and one of the harshest taunts comes from the simple tortoiseshell cat. » 3/02/12 3:00pm 3/02/12 3:00pm