Discover the diversity of life on earth and how this biodiversity has been shaped by five mass extinction events that occurred in the distant past. Each week we interview scientists about how their research informs us about the biodiversity of our planet including the earliest life forms; fish and tetrapod diversification; the radiation of reptiles and the later domination of dinosaurs; and the rise of mammals. We focus on the five previous mass extinction events to explain this incredible story of life on earth. The fossil record reveals evidence of species that went extinct during each of these catastrophic events and the recovery thereafter when surviving biota diversified. Turning to the present and the Anthropocene period, we look at how human behaviour is negatively impacting Earth’s ecosystems. We conclude by considering the threat of the so-called ‘sixth extinction’, and we discuss ways in which we can mitigate the effects of climate change and the ‘sixth extinction”.