The incredible story of how mammals took over from the dinosaurs as the largest, fastest and fiercest creatures on Earth. The mammals triumph was a roller coaster ride as they faced one of the most turbulent phases in Earth's history. At a time when birds ate horses, the mammals had to fight for their very survival.

This behind-the-scenes special details the science behind the evolution of the primates and the rise of the human race to dominance. In the process, the program attempts to answer an age-old question: was man behind the last great extinction after the Ice Age?