Professor Richard Fortey investigates the remains of ancient volcanic lake in Germany where stunningly well-preserved fossils of early mammals, giant insects and even perhaps our oldest known ancestor have been found. Among the amazing finds are bats as advanced and sophisticated as anything living today, more than 50-million-years-later; dog-sized 'Dawn' horses, the ancestor of the modern horse; and giant ants as large as a hummingbird.
In the third episode, Iain discovers the remarkable impact of just one plant: grass. On the savannah of South Africa he sees how grass unleashed a firestorm to fight its greatest enemy, the forests. He shows how cutting your finger on a blade of grass shows us how it transformed life in the oceans. In Senegal, he meets the cleverest chimps in the world. And, in the ruins of the oldest temple on Earth, he tells the extraordinary story of how grass triggered human civilisation.
The undercover cameras reveal how animals rely upon each other for a range of activities. Arctic wolves group together to survive in one of the harshest landscapes on earth, a band of hungry mongoose groom warthogs for tasty morsels - before turning their attention to Spy Warthog - and fish help clean hippos' bodies, as well as providing a unique dental service. Meanwhile, crocodiles and dikkop birds take part in a mutual neighbourhood watch against hungry prowling monitor lizards, and Spy Rattlesnake captures how prairie dogs and burrowing owls use their language skills to tell the rest of their community of approaching danger.
Since the Suez Canal's completion in 1869, more than 350 species of plants and sea creatures have migrated through it. Now, over half the marine species in the Mediterranean Sea used to live in the Red Sea, and the ecological ramifications of the canal are still being studied. Dive into the new underwater world that's resulted from this seismic migration.