The climate has changed the size of human beings | Reveal the data of a scientific study

An investigation by the Cambridge universities, located in Great Britain, and Tubinga, located in Germany, concluded that the the average body size of humans has fluctuated considerably over time and what is strongly related to temperature.

The study published in the journal Nature Communications indicates that colder climates prompted the evolution of larger bodies, while hotter and smaller bodies. Researchers believe that a larger size acts as a buffer against colder temperatures.

In turn, the study indicates that the the size of the brain has also changed dramatically, although it has not kept pace with the size of the body.

To reach these conclusions, the interdisciplinary team of researchers gathered different measurements of the body and brain size of more than 300 fossils of the genus Homo found around the world, reports an article in the Cambridge University.

By combining this data with a reconstruction of regional climates around the world over the past million years, experts have identified the specific climate that each fossil experienced when it was a living human being.

According to research, the evolution of our species is characterized by a tendency to increase the size of the body and the brain. Compared to previous species like Homo habilis, we are 50% heavier and our brains are three times the size. However, the causes of these changes are still very much debated by the scientific community.

“Our study indicates that climate – especially temperature – has been the primary driver of changes in body size over the past million years,” said Professor Andrea Manica, a researcher in the Department of Zoology at the University of Cambridge, who led the study. .

According to the specialist, “it can be seen in people who live today that those who live in warmer climates tend to be smaller, and those who live in colder climates tend to be taller.” “We now know that the same climatic influences have been at work for a million years,” he added.

The researchers also looked at the effect of environmental factors on brain size in the genus Homo, although the correlations are generally weak. Brain size tended to be larger when Homo lived in less vegetated habitats, such as open steppes and grasslands, but also in more ecologically stable areas..

After combining these results with archaeological data, it was concluded that the inhabitants of these habitats hunted large animals for food, a complex task that could have led to the evolution of larger brains.

“The environment influences the size of our body much more than the size of our brain,” said Manuel Will of the University of Tübingen.

In this way, research suggests non-environmental factors were more important than weather in driving bigger brains, among which the cognitive challenges linked to an increasingly complex social life, more diverse diets and more sophisticated technology.

The authors in turn argue that there is “strong evidence” that the size of the human body and brain continues to evolve.

In this sense, they argue that the physique of our species continues to adapt to different temperatures and that, on average, tall people currently live in colder climates.

In contrast, the size of the human brain appears to have decreased since the beginning of the Holocene (around 11,650 years ago). With this in mind, the authors suggest that growing reliance on technology, such as outsourcing complex tasks to computers, could cause the brain to shrink even more over the next few thousand years.