The State Hermitage Museum in St Petersburg is one of the largest and most visited museums in the world. Margy Kinmonth's film tells the story of its journey from imperial palace to state museum, investigating remarkable tales of dedication, devotion, ownership and ultimate sacrifice, showing how the collection came about, how it survived tumultuous revolutionary times and what makes the Hermitage unique today. Holding over three million objects and boasting more curators than any other museum, the Hermitage's story is Russia's history in microcosm and its art has lived to tell the tale

Animals and plants in the Galapagos have evolved the most surprising ways to cope with the profound geological and climatic forces.

Alice Roberts tries to find out how Stone Age people reached North and South America for the first time. She finds out about an ancient corridor through the Canadian ice sheet that might have allowed the first humans through. Old finds in Chile though point to a whole different route for the first humans making it there.

The final part examines political revolution and how art was at the forefront of throwing out 1,000 years of royal rule, from its earliest revolutionary days of enthusiasm and optimism when painting died, the poster was king and the machine-made triumphed over the handmade to the dead hand of Socialist Realism. Andrew roots out great portraits of Stalin now hidden in museum storerooms and never on public view, looks at the transformation of the Moscow metro into a great public art gallery and visits the most stunning creation of post-war Communist rule, the Space Monument. Finally, he comes to the confusion and chaos of Russia today and how it is producing some of the world's strangest art - from heroic sculptures of Russian leader Vladimir Putin to the insides of a giant erotic apple; from the recreation of the Imperial royal family facing the firing squad to sculpture in liquid oil; from Russia's embrace of the commercial art market to a return to Socialist Realism. Russia seems to stand on another brink of revolution.

Dr Alice Roberts re-traces the greatest ever journey taken by our ancestors. Thousands of years ago one small group of our species, Homo sapiens, crossed out of Africa and into the unknown. Their descendants faced baking deserts, sweat-soaked jungles and frozen wildernesses and risked everything on the vast empty ocean. Within 60,000 years they colonised the whole world... How did they do it? Why do we, their descendants all look so different?

Survival of the fittest: Raw competition? Intense cooperation? Both are essential. Interactions between and within species are among the most powerful evolutionary forces on Earth, and understanding them may be a key to our own survival.