Climate, this is how it affects the size of the human body


Temperatures would have guided the transformation of the body size of our ancestors. While they weigh less on the evolution of the brain

(photo: @Cambridge_Uni/Twitter)

Have you ever wondered why people of Nordic peoples who live in regions give colder climates, are on average more massive compared to those of peoples who inhabit warmer climates? According to researchers from the universities of Cambridge and Tübingen it was precisely the climate, in particular the temperature, to guide i changes in body size in mankind, by our ancient cousins ​​(Neanderthal, Homo, Standing man, etc) up to modern humans. Even the brain size in millions of years it is a lot change, but for the experts the link with the climate would be much more weak.

The colder, the more bulk

The Research, published on Nature Communications, is based on measurements of body and brain size as well 300 fossils gender Homo found all over the world.

Rebuilding the weather conditions relative to the regions of the globe and the time in which these ancestors lived, scientists have shown that human body size has swung quite a lot over the past million years (mankind made its appearance on Earth more than 2 million years ago, but in particular homo sapiens only about 300,000 years ago) and that colder and colder climates correspond to larger bodies.

Why? Perhaps, the researchers speculate, the larger size acts as a “bearing” against colder temperatures: a large mass in relation to the surface would allow disperse heat less.

The brain? Another story

Even the size of the brain have changed over time, with a tendency toexpansion. However, the analysis reveals one weak correlation with the climate: several factors would have contributed to shaping the human brain. “The environment has a much greater influence on the size of our body than the size of our brain – commented Manuel Will of the University of Tübingen (Germany) -. There’s a’indirect environmental influence on the size of the brain in more stable and open areas (such as prairies, ed): the amount of nutrients acquired from the environment had to be sufficient to allow the maintenance and growth of our large and particularly demanding brains in terms of energy”.

Researchers think that the main drivers that drove the changes in human brain size were the sfide cognitive (for example, with little vegetation the food sources were animals to hunt and it was necessary to devise increasingly sophisticated strategies and tools to capture them), social interactions increasingly complex, the diversification of diet.

Evolution does not stop

Scientists believe that both our bodies and our brains are getting smaller yet evolving in response to environmental factors and more.

The brain, for example, may actually shrink as it increasingly relies on computers to perform complex tasks. It is though difficult to make predictions because too many things have changed over the course of millions of years and just as many could still change.




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