Today, farming changes native life in North America. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

Did any invention do more to change life than the invention of agriculture? We first farmed around 8000 to 6000 BC, in the Middle East. After that, civilization changed utterly. We created cities. We capitalized goods. We generated the first social inequities.

So what about Native American agriculture? Archaeologists have been sifting the remains of seeds from Indian caves and rock shelters along the Mississippi and Ohio Rivers. They've learned to date them accurately. Those old seeds tell a similar story.

When we began harvesting and replanting wheat in Jericho and Mesopotamia, Indians were gathering food from the lush greenery. They ate marsh elder, sunflower seeds, and goosefoot squash.

But in Kentucky we find gourd seeds that were native to Mexico. Someone carried them north and replanted them. That means some idea of farming was as old here as it was in the Middle East.

By 2000 BC the same seeds are larger, with thinner protective coats. What's happened? Well, the seeds are larger because human hands have selected them. The coats are thinner, because when humans take care of them, seeds need less protection.

By the Golden Age of Athens, harvesting and replanting was common in America. Farming was a regular part of North American life before the birth of Christ.

Yet those crops didn't include grain. So what about the Indian grain -- corn, or maize? Maize turned up about AD 200 -- during the late days of the Roman Empire. Like wheat in the Middle East, maize was probably the result of a genetic mutation.

Maize didn't become a regular part of American farming for another 600 years. That was after AD 800 -- in the time of Charlemagne. Grain farming isn't simple. It took six centuries to invent the technology of farming corn.

Now everything changed. Fortified settlements sprang up along our rivers. Native American life became more complex and uneven. For the first time, we find wealth and poverty among Indians.

When Indians started growing grain, they triggered the same social changes that'd followed farming in the Middle East, thousands of years before. Agriculture may have been the greatest invention. But it also did most to shape our social order with all that's both good and terrible about it. And grain farming brought those same changes when it came to the Mississippi-Ohio River Basin -- 1200 years ago.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

Smith, B.D., Harvest of Prehistory. The Sciences, May/June, 1991, pp. 30-35.

For more on agriculture, see Episodes 20, 540, 960, 1121, or use the Search function to find still other episodes that deal with early agriculture and farming.