The general outline of human evolution is quite well known. But major mysteries and significant gaps still remain. This documentary provides a rapid overview of that evolution, from the dark, rainy forests of Africa, where our very first forefathers lived, some 6.000.000 years ago, to today. Fossils and archaeological sites give us a good idea of the many ecosystems that were familiar to the first hominids. With the passage of time, they gradually adapted to environments which were open and dry. They learnt to cut and carve, and the first human beings came out of Africa, equipped with the most rudimentary tools. The oldest human fossils of Europe as well as the greatest accumulation of human fossils ever discovered anywhere have been found at the Sierra de Atapuerca. With the advent of the cold, the first human beings took refuge in caves, seeking shelter, just as many generations of hominids had done before. They took with them, into the caves, the world they had known outside, painting and etching on the walls the animals that inhabited that world. Food was no longer drawn from nature through hunting, fishing or harvesting; it began to be produced via agriculture and cattle herding. That constituted the biggest economic revolution in the history of humankind.