New research has shed light on how prehistoric humans survived the cold after migrating from Africa to various parts of Europe and Asia starting at least 70,000 years ago. In a fascinating study just published in the journal Life Metabolism, a team of Chinese genetic scientists explain how a special gene variant offers extra protection from the cold to humans who possess it, increasing their capacity to live in even the most extreme northern climates.

This variant of the fat-storing FTO gene, which carries the scientific label ‘rs1421085 T>C,’ is unique because of its impact on the metabolism of a person’s brown fat cells. When the human body is exposed to cold conditions this FTO variant accelerates the process of converting potential energy to internal heat in these cells, thereby helping to regulate body temperature and keep a person safe in frigid conditions.

Evolving to Meet the Challenges of New Environments

Over the past several thousand years the different ethnic populations that comprise humanity have become well-established in the zones they occupy on the various continents. This makes it possible to perform an extensive analysis of the DNA of these diverse population groups, to check for genetic variations that might be linked to climate, or to environmental conditions in general.

That is exactly what happened in the newly published study, which was carried out by researchers from the Jiao Tong University School of Medicine in Shanghai and the Shengjing Hospital Medical University in Shenyang. They were looking to find out just how common the FTO variant that offers enhanced body heat production was in different population groups living in the Northern Hemisphere, based on the “mean earth skin temperatures” each group experienced in the month of January.

The Chinese geneticists strongly suspected they would find a correlation between the FTO variant’s frequency and exposure to lower wintertime temperatures – and that is exactly what happened.