we are the most complex creature on this planet a big brain two-legged mammal we've risen from the raw materials of the earth to dominate and shape it wind the clock backwards and the story of how we got to be us is a puzzle that defies all logic through nearly four billion years of evolutionary twists and turns disasters strike predators threatened to wipe us out from Rodin to reptiles we faced extinction at every turn from the land into the water fighting to survive every step of the way yeah from fish to work back to the very first spark of life - a single simple self this is the most extraordinary improbable story ever told the story of mankind rising four billion years ago a ball of rock and dust spins in the frozen vacuum of space yeah this isn't Mars for beans yeah this helped preserve this seething lifeless mass of molten lava will become home to nearly 9million living species