On the eve of his 69th birthday, Craig Venter looks on, amused, as his digital doppelganger shuffles from foot to foot. Venter is the biggest entrepreneur in biotech. Now his white-bearded avatar is the star of an iPad app being demonstrated to me by his head of informatics, Scott Skellenger. Dressed in jeans and a grey V-neck T-shirt, Venter’s little digital archetype can be made to walk, even dance.