David Attenborough returns in this landmark series to his most magical place on earth exploring the Great Barrier Reef aboard the research vessel Alucia. Part 1: Builders David descends beneath the waves at night in the state-of-the-art Triton submersible, the first of its kind to visit the reef. He meets some of the tiny coral animals that built the reef and helped to turn it into an underwater wonderland. He then takes to the skies to witness the vast scale of their endeavour, a living structure that provides a home for thousands of species. Using cutting-edge technology to generate computer scans of the sea floor, David learns that the Great Barrier Reef we know today is much younger than scientists ever imagined. He meets some of the people that have lived alongside it and who have told stories of its origins for thousands of years.
This episode reveals how mammals developed from tiny nocturnal forest dwellers to the dominant form of life on the planet following the death of the dinosaurs. David explains how the meteoric rise of mammals led to an astounding diversity of life and laid the foundations for the ascent of man.