In module 9, we will explore how vertebrates colonized dry land. Jesper Milàn will tell you about how this happened and give you examples of some of the first vertebrates that gradually adapted to a life on land. In the following lecture Gilles Cuny will tell you about how the early primitive vertebrates evolved into the highly diverse groups that we see today. He will show you many interesting examples of our distant relatives and discuss many of the processes, which we believe controlled their evolution and diversification. One of the important factors driving evolution is mass extinction events. Gilles will introduce you to the topic and Bent Lindow will give you a detailed look at mass extinction events. What were the causes, what happened and what were the consequences? Many questions remain unanswered but one thing is certain – mass extinctions have had a great impact on the evolution of life on Earth. Without mass extinctions life would have evolved in a completely different way and humans, like most other recent species, would not be here.