'When life got really big' - Tales from a rock whisperer

We have been plotting the history of life around the world and climate over more than 1 billion years. Tonight we will zero in on a time when the Earth's first animals came into the picture - at a time when the planet was in the grips of a massive glaciation, Snowball Earth - which is likely better named Slushball Earth. Presented on Friday 7 July 2017.