Study challenges idea that the discovery of agriculture was a disaster for health

The idea that the discovery of agriculture and animal husbandry was a disaster for the health of our species is probably an exaggeration and does not match the data obtained in several places around the world, indicates a new study.

The conclusion comes from an analysis of the changes in stature that people had throughout the so-called Neolithic Revolution, as the prehistoric phase is known in which human beings were leaving aside the hunter-gatherer life they had led for hundreds of years. of thousands of years.

People’s stature is often a good indicator of overall health during the growing up phase, and previous studies have indicated that during the Neolithic Revolution, early farmers and livestock keepers would have grown significantly shorter than their hunting and gathering ancestors. It was believed that the fault would be, in part, the predominance of a less balanced diet, based on few cereals, such as wheat or rice.

“The emerging picture we are getting from recent research is that the impact of adopting agriculture is variable from region to region and dependent on environmental and cultural conditions,” summarizes Jay Stock, professor in the Department of Anthropology at the University of Western Ontario, In Canada. Stock and his colleagues sign the new work on the subject, published in a recent edition of the specialized journal PNAS.

What Stock and company did was to gather the most up-to-date data on the Neolithic transition and compare in detail what happened to the average height of populations in different regions of the Old World from the final millennia of the Pleistocene (popularly known as the Ice Age). ).

Some of the areas studied are considered Neolithic “centres of origin”, that is, regions where the practice of agriculture and animal husbandry evolved independently. This is the case of the Levant (Middle East) and China.

Elsewhere, Neolithic practices arrived as export items, in a process that involved both the migration of original farmers and the adoption of these technologies by native inhabitants. This is true for Europe as a whole, where the Neolithic Revolution spread over thousands of years, first in the southeast (Greece, for example) and lastly in the northwest (Scandinavia, the United Kingdom and Ireland).

Finally, some places seem to include a mixture of imported ideas and very old local domestications, such as South Asia (Pakistan and India) and Egypt.

Not all of these regions have a sufficiently extensive record of the ancient skeletons of their inhabitants. However, in some of the places, these data range from the Pleistocene to much more recent times, as is the case of the Levant.

The new analysis shows that, in the Middle East, the average height of men had already been declining since at least 20,000 years before the present, almost 10,000 years before the presence of agriculture proper, while that of women barely changed over time. of that period.

In China, however, there are practically no changes among both men and women after adopting agricultural practices. Decrease in height appears somewhat clearer in southern Europe and southern Asia, with similar effects for men and women.

Based on these data, the team proposes that the negative effects of the Neolithic Revolution on health were smaller or non-existent in the case of populations that developed agriculture on their own, thanks to the particular conditions of their environment, and went through a gradual and long transition of styles of life.

The most surprising situation, however, is that of Central and Northern Europe. There, the period between 8,000,000 years ago and 4,000 years ago is marked by a considerable increase in height. Based on genetic and archaeological data, the researchers propose that the key may have been the adoption of the consumption of milk and derivatives.

In fact, also around this time, a small alteration in the DNA that favors the consumption of milk after weaning becomes common in the populations of the region. This happens by continuing to produce a substance that helps digest liquid, lactase.

According to Stock, none of this means that the Neolithic was all flowers. “There is still good evidence of an increase in infectious diseases associated with sedentary living, as well as a general increase in fertility rates and population size, but these trends do not unfold identically in all circumstances,” he explains. Population growth may have exacerbated conflicts between groups, for example.