DNA Pearl, 9.30pm Fifty years ago, two unknown scientists burst into a pub in Cambridge and declared: 'We have found the secret of life!' Dr James Watson guides us through the events of the heated scientific race that led to a double helix model being built by Dr Francis Crick and himself, and their winning the Nobel prize. Groundhog Day Star Movies, 9pm A weatherman (Bill Murray) who covers Groundhog Day every year, suddenly gets stuck living the same day over and over. He eventually realises he must take life into his own hands, and change his ways if he ever wants to get to the next day. Also starring Andie MacDowell.