"Long before the first kings, priests, or merchants inscribed their deeds in clay or papyrus, humans were altering ecosystems simply by moving through them. The great dispersal of our species out of Africa, beginning roughly 60,000–70,000 years ago, reshaped continents. Wherever humans arrived, waves of extinctions followed: giant marsupials in Australia, mammoths and mastodons across the Americas, enormous birds in New Zealand and Madagascar. These losses were not caused by Western civilization, or any civilization at all, but by small bands of foragers equipped with nothing more than stone tools, spears, and fire."