Many animals hibernate for winter. They stock up on food and hide away in hole or cave to escape snow and cold. Scientists now believe early human beings may have hibernated too. The scientists looked at fossils of bones from our early ancestors who lived around 430,000 years ago. bones were found in site in the north of Spain. scientists are experts in studying fossils and ancient bones. They say that cuts and other signs of damage on bones they examined are similar to those on bones of animals who hibernate, like bears. They also say that early humans may have hibernated to escape extreme cold. Winters were much colder hundreds of thousands of years ago.
scientists looked at the bones of several dozen humans. Scientist Antonis Bartsiokas said there is evidence that early humans slowed down their metabolism so they could survive longer in winter without food. However, humans could not slow their metabolism like bear. Bears can wake up after months of hibernation and their body will be same as when they went into hibernation. bones of early humans showed people suffered health problems because of hibernation. Many of problems were caused by lack of vitamin D, which we get from sunlight. This can make our bones weaker. researchers said: "We have to emphasise that hibernations are not always healthy."