How Rapidly Is the Human Population Growing?
Evidence from fossils and studies of ancient cultures suggests that the current form of our species, Homo sapiens sapiens, has walked Earth for about 60,000 years (some recent evidence suggests 90,000-176,000 years), an instant in the planet’s estimated 4.6-billionyear existence. Until about 12,000 years ago, we were mostly hunter-gatherers who moved as needed to find enough food for survival. Since then, three major cultural changes have occurred: (1) the agricultural revolution (which began 10,000-12,000 years ago), (2) the industrial revolution (which began about 275 years ago), and (3) the information and globalization revolution (which began about 50 years ago). These major cultural changes have given us much more energy (Figure 1-3, p. 4) and new technologies with which to alter and control more of the planet to meet our basic needs and increasing wants. . Allowed expansion of the human population (Figures 1-1 and 1-4, p. 4, and Spotlight, p. 6), mostly because of increased food
