This document discusses history, science, and trade. It summarizes that history is based on primary and secondary sources and must meet three factors: reliable witness, logical possibility, and observable causes and effects. It then discusses the migration patterns of early humans out of Africa around 60,000 years ago and their colonization of Asia, Australia, and North America. It also summarizes how scientists used ice cores, tree rings, and carbon dating to determine that a large volcanic eruption around 535 AD caused global cooling and catastrophe.