Scientists Suspected The Climate Of Influencing The Body Size Of Human Ancestors
The typical body size of our ancestors directly depended on the average temperatures of the Earth's surface. That is typical for at least the last million years, anthropologists write in the scientific journal Nature Communications.
"Even today, it can be noticed that people living in the warm regions of the planet are usually inferior in size to residents of temperate latitudes. Our study shows that over the past million years, the main driving factor in the evolution of the human body was the climate, and, in particular, the temperature of the environment," said one of the authors of the work, Professor Andrea Manica of the University of Cambridge.
Anthropologists believe that climate has played a very important role in human evolution. For example, 3 million years ago, the climate of Africa became more arid and hot, which is why the ancestors of Australopithecus and the first representatives of the genus Homo changed their habitat from trees to savannas. And when the Cro-Magnons got to Eurasia, their skin and hair gradually became lighter, and the shape of their face and nose changed so that their body began to lose less heat during cold winters. A new study has shown that the change in the Earth's climate could still control the body size of our ancestors.
Manika and his colleagues studied more than 300 remains of ancient representatives of the genus Homo, who lived for the last million years – Cro-Magnons, Neanderthals, Heidelberg, and erect man. Anthropologists were interested in three parameters – the mass, height, and size of the brain. All these indicators have greatly increased with the evolution of our genus, but scientists have not yet decided on an unambiguous reason why this happened.
The analysis showed that the size of the brain of our ancestors and their relatives was practically not affected by climate fluctuations. Most of all, this parameter was influenced by the habitat: the less wooded and more open it was, the larger the brain was.
However, in terms of height and mass, the climate was one of the main factors of evolution. As a rule, the lower the average ambient temperature, the taller and larger were the representatives of the genus Homo who lived in such conditions. That was typical both for the ancient ancestors of modern humans and for Cro-Magnons and Neanderthals.
In this respect, as the researchers note, a person does not differ from all other inhabitants of the Earth. On average, the size of organisms that live in temperate and circumpolar latitudes is larger than those who live in the vicinity of the equator.