Did you know that today scientists are actually producing mice that tweet like birds, cats that glow in the dark, "monster salmon", "spider goats", cow/human hybrids, pig/human hybrids and even mouse/human hybrids? The very definition of life on earth is changing right before our eyes. Many scientists believe that genetic modification holds the key to feeding the entire planet and healing all of our diseases, but others are warning that genetic modification could literally transform our environment into a desolate wasteland and cause our world to resemble a really bad science fiction movie. For decades, scientists around the globe have been fooling around with DNA and have been transplanting genes from one species to another. But now technology has advanced so dramatically that just about the only thing limiting scientists are their imaginations.