Hunter-gatherers worked less, had more varied diets, and better health – so shy did we switch to agriculture?
Oh, agriculture. On paper, farming and domestication sounds pretty good – have some land, grow some food, raise some animals. It's one of the things that has gotten us to where we are today, for better or worse. (Given the habitat destruction, soil damage, water contamination, animal rights issues, and loss of crop biodiversity, for starters, I'm going with "worse.")
But hunters and gatherers had it pretty good – they worked less, ate a greater variety of food, and were healthier. So what nudged them into farming? According to a new study from the University of Connecticut, the shift away from hunting and gathering towards agriculture has long been baffling to scientists. And that the switch happened independently around the globe heightens the mystery."A lot of evidence suggests domestication and agriculture doesn't make much sense," says Elic Weitzel, a Ph.D. student in UConn's department of anthropology and lead author of the study. "Hunter-gatherers are sometimes working fewer hours a day, their health is better, and their diets are more varied, so why would anyone switch over and start farming?"
It's a question that many have pondered, and in doing so have arrived at two plausible theories. One is that in times of abundance humans had the leisure to start experimenting in the domestication of plants. The other theory suggests that in lean times – thanks to population growth, over-exploitation of resources, a changing climate, et cetera – domestication was a way to supplement diets.
So Weitzel decided to test both theories by analyzing a specific place, the Eastern United States, asking, "Was there some imbalance between resources and the human populations that lead to domestication?"
He started testing both theories by looking at animal bones from the last 13,000 years, recovered from six archeological sites of human settlements in northern Alabama and the Tennessee River valley. He also looked at pollen data taken from sediment cores gathered from lakes and wetlands; the data provides a record about the plant life form different periods.
As UConn explains, Weitzel found evidence that forests of oak and hickory trees began to dominate the areas as the climate warmed, but also led to decreasing water levels in lakes and wetlands. As the study notes, "Climatic warming and drying during the Middle Holocene, growing human populations, and oak-hickory forest expansion were the likely drivers of these changes in foraging efficiency." In the meantime, the bone records revealed a shift from diets rich in water fowl and big fish to smaller shellfish.
"Taken together, that data provides evidence for the second hypothesis," says Weitzel. "There was some kind of imbalance between the growing human population and their resource base, effected perhaps by exploitation and also by climate change."
Uhm, deja vu, much?
But that said, it's actually not so cut and dry. Weitzel also found indicators subtly pointing to the first theory as well. The new forests boosted game species population. "That is what we see in the animal bone data," says Weitzel. "Fundamentally, when times are good and there are lots of animals present, you'd expect people to hunt the prey that is most efficient," says Weitzel. "Deer are much more efficient than squirrels for example, which are smaller, with less meat, and more difficult to catch."
But even so, if larger game, like deer, is over-hunted, or if the landscape changes to one less favorable for the animal population, humans must subsist on other smaller, less efficient food sources, notes UConn. "Agriculture, despite being hard work, may have become a necessary option to supplement diet when imbalances like these occurred."
In the end, Weitzel concludes that the findings point to theory number two: that domestication came about as food supplies became less than ideal.
"I think that the existence of declining efficiency in even one habitat type is enough to show that ... domestication happening in times of plenty isn't the best way to understand initial domestication," he says.
Weitzel also believes that looking toward the past at questions like this – and how humans coped and adapted to change – may help to enlighten us in the face of today's warming climate. "Having an archaeological voice backed by this deep-time perspective in policy making is very important," he says.
Given that progress is what has sparked this round of climate change, if only we could turn our course around and start hunting and gathering again. Less work, more varied diets, and better health? Why would we want anything else?