It's not often that a hairball makes headlines. But that's what happened this November, when Penn State biochemistry professor Stevan Schuster announced that he had reconstructed 80% of the genome of the long extinct woolly mammoth, using clumps of hair from the remains of several of the giant critters. The job involved not just piecing together more than 3 billion DNA sequences, but making sure none of the material that was used came from bacteria or other organisms clinging to the fur. The work raises the inevitable Jurassic Park question and the answer is, no, we won't see wooly mammothpopulated theme parks any time soon. But the key word is soon. Stephan doesn't rule out the possibility forever.