Over the past few million years, the average size of the human body has evolved significantly. According to a recent study, this would be one of the effects of climate change. On the other hand, the climate would have nothing to do with the evolution of the size of the brain.
Researchers from the universities of Cambridge (UK) and Tübingen (Germany) became interested in the family Homo , to which obviously belongs Homo Sapiens . Scientists have collected data on the size of the brain and body of more than 300 fossils . The results of their analysis were published in the journal Nature Communications July 8, 2021.
The study leaders were able to calculate the climate in which each of the individuals lived. To achieve this, the researchers associated the data collected on the fossils with the reconstruction of the climates of the different regions on Earth for the past few million years. According to the results, the climate and more particularly the temperatures were one of the main factors of a evolution of the size of the bodies. The study suggests that cold and hostile climates are linked to larger bodies while hot climates generate a decrease in corpulence.
The researchers also explained that the current climate change is unlikely to affect our body size, at least for now. According to Andrea Manica, an expert in evolutionary ecology and the main leader of the study, the evolution that the study highlights took place over thousands, even tens of thousands of years.
In addition, scientists have looked for links between brain size and environmental factors. According to the results, the reasons why Homo Sapiens has a brain three times bigger that Homo Habilis and other species remain uncertain. However, Andrea Manica indicates that surprisingly, the evolution of brain size has no link with the evolution of temperatures . This implies that the body and the brain have not been subjected to the same constraints. Nevertheless, the study provided insight that larger brains were found in more stable environments. It must be said that the brain requires a lot of energy. Thus, it is difficult to properly maintain it without sufficient resources.
Finally, if the current global warming does not yet impact the size of the human body, other animals are concerned by a change in their morphology. Some migratory birds in North America or some snakes and other turtles are gradually shrinking in size due to global warming temperatures.
