Tools and machines have allowed us to overcome our physical limitations, and become the most successful species on Earth. But tools are also transforming what it means to be human.

Early man rubbed two sticks together and created fire. We learn to cook our food, saving vital energy. As a result, our brains expand--making us the most intelligent species on the planet. Armed with fire, we experiment by heating minerals to make stronger tools allowing us to fight wars and build civilizations. But burning wood destroys our landscape, so Mankind exploits a new energy--oil.