Baby boom in Southwestern Native Americans (Image 2)

Ears of corn, or maize, from a "Basketmaker II period" cache in Colorado dating to the third century B.C. Maize was grown in the Southwestern United States as early as 2000 B.C. and by 400 B.C., the crop provided 80 percent of the region's calories. [Image 2 of 6 related images. See

Source: NSF Multimedia Gallery - August 16, 2017 Category: Science Source Type: video