First Life and David Attenborough's Rise of Animals: Triumph of the Vertebrates is a 2010 and 2013 British nature documentary series written and presented by David Attenborough, also known by the expanded titles David Attenborough's First Life (UK) and First Life with David Attenborough (USA). It was first broadcast in the USA as a two-hour special on the Discovery Channel on 24 October 2010. In the United Kingdom it was broadcast as a two-part series on BBC Two on 5 November 2010. First Life sees Attenborough tackle the subject of the origin of life on Earth. He investigates the evidence from the earliest fossils, which suggest that complex animals first appeared in the oceans around 540 million years ago, an event known as the Cambrian Explosion. Trace fossils of multicellular organisms