Nicholas St. Fleur writes: Somewhere in a dense forest of ash and elm trees, a hunter readies his spear for the kill. He hurls his stone-tipped weapon at his prey, an unsuspecting white-tailed deer he has tracked since morning. The crude projectile pierces the animal’s hide, killing it and giving the hunter food to bring back to his family many miles away. Such was survival circa 5,000 B.C. in ancient North America.

But today, the average person barely has to lift a finger, let alone throw a spear to quell their appetite. The next meal is a mere online order away. And according to anthropologists, this convenient, sedentary way of life is making bones weak. Ahead, there’s a future of fractures, breaks, and osteoporosis. But for some anthropologists, the key to preventing aches in bones is by better understanding the skeletons of our hunter-gatherer ancestors.

“Over the vast majority of human prehistory, our ancestors engaged in far more activity over longer distances than we do today,” said Brian Richmond, an anthropologist from the American Museum of Natural History in New York, in a statement. “We cannot fully understand human health today without knowing how our bodies evolved to work in the past, so it is important to understand how our skeletons evolved within the context of those high levels of activity.”

For thousands of years, Native American hunter-gatherers trekked on strenuous ventures for food. And for those same thousands of years, dense skeletons supported their movements. But about 6,000 years later with the advent of agriculture the bones and joints of Native Americans became less rigid and more fragile. Similar transitions occurred across the world as populations shifted from foraging to farming, according to two new papers published Monday in the Proceedings of the National Academies of Sciences. [Continue reading…]