Nature, disease, and globalization: An evolutionary perspective
Contemporary globalization represents the culmination of a long evolutionary process that has produced larger and more complex social units over time. Although precursors of contemporary complex human societies emerged in eastern Africa more than 300,000 years ago, our interest in Homo sapiens the globalizer begins about 100,000 years ago, when small bands of our species began to migrate out of eastern Africa toward the north and west. The factors responsible for this migration out of Africa remain speculative, but population growth, climate change, ﬂuctuating food supplies, and human curiosity undoubtedly were involved. Within 60,000 to 70,000 years, bands of Homo sapiens had settled in the far corners of the world, showing a remarkable ability to adapt to the most varied environments (Cavalli-Sforza and Cavalli-Sforza, 1995).