July 9, 2021 01:20 GMT
Scientists note that the factors driving these changes are still debated.
The study found that the average human body size has fluctuated significantly over the past million years and is strongly related to temperature published This Thursday in Nature Communications.
Research authors they point that colder and more extreme climates are at the evolutionary origin of large bodies, while warmer climates have given rise to smaller bodies. As for the size of the brain, it also changed significantly, although it did not develop in parallel with the size of the body.
Researchers collected body and brain measurements from more than 300 fossils of the human race It is found all over the world. Our species, Homo sapiens, originated about 300,000 years ago in Africa, but the Homo genus has been around for much longer and includes Neanderthals and others. extinct species related, such as Homo habilis and Homo erectus.
Combine fossil data with a Reconstructing Climates From different regions over the past million years, the specific climate in which each of these humans lived has been determined.
In colder climates, larger body size served as Freezing Temperature BufferScientists have shown that the body loses less heat when it has a large mass.
Did the weather also affect brain size?
The distinguishing feature of the evolution of our species is the tendency to increase body and brain size; Because compared to previous species, such as Homo habilis, we are 50% heavier and have Brains are 3 times bigger. However, the driving factors for these changes are still debated.
“Our study indicates that climate, especially temperature, was الحرارة main driver “Body size has been changing over the past million years,” says Andrea Manica, a professor at the University of Cambridge (UK) and lead author of the study. Something similar is observed today, because those who live in cold regions tend to be taller and maneka added.
In addition, they note the influence of environmental factors on brain size In the genus Homo, though, relationships were generally weak. Brain size tended to be larger when humans lived in less vegetative habitats, but also in more ecologically stable areas. Combined with archaeological data, the results suggest that the people who lived in these habitats They were hunting big animals As food, a complex task that would have fueled the evolution of larger minds.
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