Africa is the mother continent, the core from which all the other continents were torn away 100 million years ago. Since then, three factors have had profound consequences on its wildlife. This mighty block of land has stayed in much the same place - it stands alone and it straddles the equator. It has also been protected from crippling ice ages and destructive invasions as well as nurtured by gentle changes in climate and geology. As a result, animals and plants have flourished here more successfully than on any other continent. This is Africa - rich, diverse, fascinating, and the heart of the world. Time is the key to our series. Influenced by climate and geology, time has allowed Africa to accumulate the breathtaking variety of wildlife we see today.