What is the music from the latest BBC advert about an upcoming natural history programme with David Attenborough?

Ludovico Einaudi - I Giorni If you mean the trailer for the documentary series Life, which included a shot of a lizard running on water, then the music is by ES Posthumus and called Unstoppable. It is only available as a download from iTunes or Amazon. I recently heard it at the cinema on the trailer for the new Sherlock Holmes movie and thought it was from the soundtrack of that film, but strangely it is not. But that helped me to track down this fantastic piece of music.