To me that sounds like pure fantasy. I tuned out as soon as Dr Chaffee said that native Americans and aboriginal Australians were pure carnivores. The hunter/gatherer myth is just that a myth. no culture ever has lived on only meat, with the Inuit possibly coming the closest but who still harvest and store greens both from the sea and land during their short summer months. spending a lot of energy and resources to get that in their diet, even eating the partially digested vegetarian contents of caribou stomachs.. There is also no traditional culture that is vegan. Both of those options are completely unrealistic and unpractical and unhealthy. the current era of meat everywhere and everything is an absolute anomaly with feedlots and government subsidized petroleum and feed stock, and deforested rainforest. As is the huge reliance on sugar, white rice and white flour in our diets. Meat is something that was eaten when people were successful in their harvest or hunt and could spare a cow or the oxen got sick.
Native Americans who lived with the buffalo also ate the bounty from the earth. Native Americans are responsible for the development of Squash, Beans, Peppers, Tomatoes, wild rice, potatoes, corn, pecans, sunflowers, chia, sweet potatoes, avocados, papayas, pinapples, quinoa, and many other types of fruits, all of which were unheard of in the East. The Aztecs and Maya and southern tribes figured out how to breed and nixtamalate corn, the most technologically advanced purely human developed grain capable of totally human controlled genetic manipulation. the incas created thousands of varieties potatoes and quinoa.
When the Europeans "discovered" America and the wonderful ingenious corn that was eaten here they took it back to Europe but forgot to take the Nixtamilization process as well back with them. As a result when it was introduced as a staple, people started dying of niacin deficiency. Referring to Native Americans as simple Hunter Gatherers, fails to capture even a portion of the whole story.
The natives of California cultivated acorns as a staple and fought pitched battles over the most productive oak groves. One quick look at aboriginal Australian diets shows a wide variety of seeds, nuts, fruits, tubers, even a traditional bread prepared from seeds.
And if for some reason if you are right that humans are designed to only eat meat, still to hell with that. That sounds like an absolutely miserable life. But to each their own.
