humn brain evolved too

Rule #2 The human brain evolved, too. • We don’t have one brain in our heads; we have three. We started with a “lizard brain” to keep us breathing, then added a brain like a cat’s, and then topped those with the thin layer of Jell-O known as the cortex—the third, and powerful, “human” brain. • We took over the Earth by adapting to change itself, after we were forced from the trees to the savannah when climate swings disrupted our food supply. • Going from four legs to two to walk on the savannah freed up energy to develop a complex brain. • Symbolic reasoning is a uniquely human talent. It may have arisen from our need to understand one another’s intentions and motivations, allowing us to coordinate within a group