In 1532, when Francisco Pizarro met Incan emperor Atahualpa in what would later become modern-day Peru, Atahualpa’s men outnumbered him 476 to one. And yet Pizarro captured him within minutes. He held Atahualpa prisoner for eight months, persuaded the Incas to give him enough gold to fill an entire room to the ceiling and then, when he had what he needed, executed the monarch and took over the empire. How did the Spanish manage to annihilate an entire civilization? The answer is in the title of UCLA professor Jared Diamond’s 1997 book: guns, germs and steel. (Also horses: Incan warriors fought on foot while the Spanish rode on horseback.) According to Diamond, the history of civilizations isn’t a simple history of “savage” cultures being dominated by more advanced peoples. It is a slow, evolutionary process that results in one part of the world’s developing a set of tools that just happen to be more effective than those developed by another.