Mesoamerica would deserve its place in the human pantheon if its inhabitants had only created maize, in terms of harvest weight the world's most important crop. But the inhabitants of Mexico and northern Central America also developed tomatoes, now basic to Italian cuisine; peppers, essential to Thai and Indian food; all the world's squashes (except for a few domesticated in the United States); and many of the beans on dinner plates around the world. One writer has estimated that Indians developed three-fifths of the crops now in cultivation, most of them in Mesoamerica. Having secured their food supply, Mesoamerican societies turned to intellectual pursuits. In a millennium or less, a comparatively short time, they invented their own writing, astronomy, and mathematics, including the zero.