From the Ice Age to the late 19th century, Native Americans had pursued nomadic ways of life in what's now Texas for more than 12,000 years. It's possible for a contemporary outsider to imagine those ways of life were timeless, unchanging. In fact, indigenous life here is a history of adaptation, innovation and change. As populations grew, hunter-gatherers developed new techniques to survive in this land.

It's a process called intensification, and archeologists are just beginning to trace its history.

The first people to enter the Americas had diverse hunting and cooking technologies at hand. They knew how to make unleavened bread. They could roast plants in earth ovens.  

But they...