Powerful forces have forged the conditions on Earth that have made life possible. The millennia have been witnesses to the formation of the planet: its singular position in relation to the sun, the evolution of the continents, and the birth of entire mountain chains. All of these elements combine to create Earth’s constantly changing climate. Homo sapiens emerge into this unpredictable and violent world, fighting for survival from the start. It is these early humans’ ability to adapt that allows them to triumph even in the face of incredible adversity and sets the path for modern man. Part of the "How Climate Made History" series.