´óÏó´«Ã½

Professor Brian Cox visits the Burgess Shale, a very important fossil field in Yoho National Park in the Canadian Rocky Mountains. The fossils here record an explosion of life around 540 million years ago, during the Cambrian period, known as the ‘Cambrian explosion’. He explains a speculative theory that the evolution of creatures with eyes, such as trilobites, triggered the evolution of more complex forms of life.