Unfit for Agriculture?

If we were to travel back in time 2 million years, we would find the earliest representatives of the human genus in Africa. We could see that they had adapted to a highly mobile hunter-gatherer lifestyle, walking kilometers and kilometers a day. A lifestyle that humans have maintained for 1,987,000 of the 2,000,000 years we have been on this planet.

If we pay attention to these two large numbers, we will see that there is only a difference of about 13,000 years. These are the last years of human history, which have been lived in a radically different lifestyle. This radical change was brought about by the adoption of agriculture, the domestication of plants and animals, which began to appear about 13,000 years ago, independently in different parts of the world.

This small modification in the way of subsistence drastically changed the history of the human genus. Mainly because of the dependence it placed on us on the foods we chose to domesticate, just a handful, compared to the high variety that characterized the diet of hunter-gatherers. But, of equal importance is the sharp abandonment of mobility that had characterized the human genus for 1,990,000 years.

Lightweight Bones

A December 2014 study published in Proceedings of the National Academy of Sciences shows that human bones became increasingly gracile in cultures that adopted agriculture. The bones of our hunter-gatherer ancestors were 20 percent more massive.

This would not have to do with a change in diet, the authors say, but with a loss of mobility due to the transition to a sedentary life. It would not be an evolutionary change that we have been passing down from generation to generation, but that from a young age we have less activity than hunter-gatherer children, so our bones grow weaker.

One of the authors of the study, Colin Shaw of the University of Cambridge, Great Britain, had published another similar study in 2013 in the Journal of Human Evolution, in which he compared the bones of hunter-gatherers from about 50,000 years ago with those of ordinary modern humans and athletes.

Athletes vs. Prehistoric Hunters

The results would make even athletes who exercise 5-6 hours a day and run 80-100 miles a week pale in comparison. A prehistoric hunter-gatherer had exactly twice as much daily physical activity as a professional athlete. This is because... those hunter-gatherers from 50,000 years ago used to roam an area of ​​between 1,150 and 1,930 square miles.

It's best not to mention where the average modern human falls on this scale, so as not to be embarrassed. Well, at your insistence, we can tell you that a person who exercises at least twice a week does not even reach a third of the physical activity of that prehistoric ancestor.

"It is not agriculture that makes us weaker or more prone to certain diseases, it is lifestyles," says Argentine anthropologist José Luis Lanata, CONICET researcher and director of the Institute for Research on Cultural Diversity and Change Processes.

"Without a doubt, an extremely sedentary life like the one we are leading today in cities, spending 8 hours sitting in front of a computer, produces changes in different organs, in our bones, in our eyesight," Lanata continues. "A monotonous diet like the one produced by agriculture generates problems, while a varied diet is what we have evolved for. But it is also bad for our health not to have physical activity."

Unfit for Agriculture?

Our body, which evolved for millions of years to adapt to a highly mobile lifestyle, even superior to that of an Olympic runner today, had to start adapting in just 13,000 years to spending 90 percent of its day sitting, almost without mobility. This brings us problems such as back pain, among others. So, are we maladapted?

"I don't think we are either adapted or maladapted," says Scientific American Carles Lalueza Fox, an expert in paleogenetics at the Institute of Evolutionary Biology (joint center of the CSIC and the Pompeu Fabra University), Spain. "There is a current trend (which is even reflected in fashions such as the paleo diet or paleotraining) to consider the hunter-gatherer way of life as healthier; I don't think it was like that; clearly the agricultural way of life had various advantages that favored its expansion, including a population increase and the possibility of storing food surpluses."

"It is evident that this had to constitute a great selective force and that we are, at heart, the descendants of the farmers who survived these adaptive challenges," concludes Lalueza Fox.