Using new 3-D methods to analyze stone projectile points crafted by North America's earliest human inhabitants, scientists have found that these tools show evidence of a shift toward more experimentation about 12,500 years ago, following hundreds of years of consistent stone-tool production. The findings provide clues into changes in social interactions during a time when people are thought to have been spreading into new parts of North America.

Source: Traces of adaptation and cultural diversification found among early North American stone tools