During the mega-drought from 7,500 to 6,000 years ago, North America heated up and La Nina became permanent. We’re headed into our third year of La Nina so you probably know that this climate mode is characterized by drought, punctuated by tropical storms from the Gulf and especially cold spells in winter. During this time moisture-loving grasses disappeared, leaving the ground exposed to erosion. A new study of the Brazos River from this time probably holds true for the Bosque River, large, violent thunderstorms scoured away huge amounts of soil along the rivers, meandering back and forth over the centuries and removed earlier camp sites. All this silt settled below Waco and along the Texas beaches. It wasn’t long before drought grasses like buffalograss and the gramas spread over Texas, along with very low glycemic food plants like prickly pear, Texas thistle, yucca, and mesquite. There were stone ovens to bake away the toxins from various roots and tubers, but these foods could be eaten raw. The glycemic index is a measure of how fast your body processes sugar, it runs from 0 to 100, with a doughnut rated at 100. The study of coprolites (dried human feces found in caves) suggest that an Altithermal meal would run about 25 glycemic units. These Native Texans and especially the ones who lived in far West Texas where the Altithermal drought never ended, developed near perfect digestive efficiency, but at a price, the coprolite studies show that they consumed up to 300 grams of indigestible fiber per day. People today are consuming an unhealthy 15 grams. This near perfect metabolism has crashed into potato chips and hamburgers today – leaving the descendants of these people vulnerable to obesity and diabetes.