Climate change has been identified as the main cause of human evolution
A joint study by scientists from the universities of Cambridge and Tübingen demonstrated how climate change has affected the human body. Experts have analyzed more than 300 fossils found around the world, according to Nature Communications.
Among the finds were not only Homo sapiens, but also its now extinct relatives. The data obtained were combined with the reconstruction of the regional climatic conditions of the world over the past million years.
The results showed that during this time (one million years), the average human body size fluctuated significantly. The inhabitants of the colder regions were the largest. It is believed that the impressive dimensions protect against low temperatures: in this case, the body loses less heat.
Scientists noted that the main feature of the evolution of our kind is the increase in the size of the body and brain. Thus, Homo sapiens is 50% heavier than Homo habilis, who lived more than 2 million years ago, and his brain is three times larger. But it is still unclear what caused these changes.
The authors of the new study concluded that the main driving force behind the changes in the human body was the climate. Even in modern populations, it can be seen that the inhabitants of warm latitudes are distinguished by their miniature constitution, and the inhabitants of cold places are noticeably larger.
“The same climatic influences have been in effect for the last million years,” noted the authors of the scientific work.
The study also showed that environmental factors influenced brain size, although not so clearly. For example, those with a larger brain lived in regions with a small amount of vegetation, where large animals were the main prey. Obviously, hunting them required mental activation.
Scientists noted that the human body continues to evolve today. The human body changes with ambient temperatures. The brain size of Homo sapiens has been decreasing since the beginning of the Holocene (about 11,650 years ago). It is likely that dependence on technology, when complex tasks are performed exclusively by computers, will lead to an even more pronounced decrease in the brain in the next few thousand years.
Earlier it was reported that scientists have traced the evolution of the mammalian brain. They “looked” 150 million years into the past.
