Over time, humans have evolved so much that it is sometimes hard to believe that we really came from creatures that, some two million years ago, were only 1.20 meters tall, completely covered in hair, and just beginning to stand tall. shyly on their lower limbs to go from being quadrupedal to bipedal.
Since then things have changed a lot, we no longer live in trees or in caves, and we have gone from carving stones to building spaceships, but the obvious differences that separate us from our first ancestors did not arise suddenly, but are the fruit of Hundreds of thousands of small changes that slowly accumulated over the millennia. To appreciate significant differences between one and the other members of the human family, we normally have to analyze individuals separated by hundreds of thousands of years of evolution.
But there are times when things seem to go faster. According to anthropologist Clark Spencer Larsen of Ohio State University, if we were to choose the most dynamic and impactful period in our entire history, the one that has most influenced the way we live today, we wouldn’t have to go back that far in time. . In fact, it would be enough to go back about 12,000 years, because “our modern world began with the advent of agriculture, and going from having to look for food to growing it was something that changed everything.”
Agriculture, for example, allowed humans to create the first stable settlements. Cultivating, in effect, means not having to continually travel large geographical areas in search of herds of herbivores or in search of seasonal wild fruits. Producing food in situ implies being able to store it to consume it when it is most convenient, and that in turn means always staying close to those stores, going from a nomadic life to a sedentary one, creating permanent settlements that, over time, ended up becoming towns and prosperous cities.
The other side of the coin
But according to Larsen, organizer and editor of a special section in this week’s issue of ‘Proceedings of the National Academy of Sciences’ (PNAS) and co-author of two of the eight articles that make it up, along with the first cultures of humans they also planted the seeds for many of the most serious problems in modern society. In the words of the researcher, “although the changes brought about by agriculture have brought us a lot of good, they have also generated an increase in conflict and violence, increasing levels of infectious diseases, reduced physical activity, a more restricted diet and more competition for food.” means”.
The eight articles in the PNAS special section focus primarily on the field of bioarchaeology: the study of human remains and what they can tell us about changes in diet, behavior, and lifestyle during approximately the last 10 millennia. And one of the common threads of all the articles is precisely that the main problems of our society have very ancient roots. “We didn’t get where we are now by chance,” says Larsen. The problems we have today with wars, inequality, disease, and poor diets all resulted from the changes that occurred after the beginning of agriculture.”
The cultivation of food allowed the world population to grow from about 10 million individuals in the Pleistocene to more than 8 billion today. Which, of course, had more than one cost. The varied diet of the foragers, for example, was replaced by a much more limited diet of domesticated plants and animals, often of inferior nutritional quality. Currently, Larsen points out, much of the world’s population depends on three foods: rice, wheat and corn, especially in areas that have limited access to animal protein sources.
Another major change was the addition of dairy to the human diet. In one of the papers, the researchers examined dental calculi found in fossils to show that the earliest evidence of milk consumption dates to around 5,000 years ago in northern Europe. “This is proof,” Larsen writes, “that humans were genetically adapted to be able to consume cheese and milk, and that this happened very recently in human evolution.”
profound social changes
As farming communities began to emerge, drastic social changes also occurred. Another paper, co-authored by Larsen, analyzes strontium and oxygen isotopes in tooth enamel from early farming communities from more than 7,000 years ago to help determine where the residents were from. And the results show that Çatalhöyük, in modern Turkey, was the only one of several communities studied where non-locals apparently lived. “The foundations of kinship and community organization that would later develop in later West Asian societies were being laid.”
These first communities also had, for the first time, to face the problem that many people live in relatively small areas, which is a continuous source of conflict. In another of the papers, researchers studying human remains in early farming communities in western and central Europe found that around 10% died from traumatic injuries.
Violence, disease and climate change
“The analysis – Larsen writes – in the introduction reveals that violence in Neolithic Europe became an endemic and continuously increasing problem, resulting in patterns of warfare that caused increasing numbers of deaths.”
The research also reveals how these early human communities came to create the ideal conditions for another problem that looms large in today’s world: infectious disease. Farming animals, Larsen notes, led to the common zoonotic diseases that can be transmitted from animals to people.
Regarding the modification of the environment and its effects, and although the current climate change crisis is unique in the history of humanity, societies of the past also had to deal with short-term climatic disasters, in particular prolonged droughts. In one of the articles, the researchers point out that economic inequality, racism and other types of discrimination were key factors in how societies have fared in these climate emergencies. In fact, Larsen explains, communities with more inequality were more likely to experience violence in the wake of weather disasters.
In a blink of an eye
But what is most surprising according to the researcher is that all the changes documented in the eight articles occurred extraordinarily quickly. “When you look at the roughly 6 million years of human evolution, this transition from foraging to farming and all the impact it has had on us happened in the blink of an eye. On the scale of a human lifetime, that may seem like a long time, but it really isn’t.”
Another of the conclusions of the work is the amazing ability of humans to adapt to their environment. In Larsen’s words, “We are remarkably hardy creatures, as the past 12,000 years have shown. And that gives me hope for the future. We will continue to adapt, to find ways to successfully meet challenges. That’s what we do as humans.”