One of the biggest unsolved puzzles in the evolution of mankind is why humans were the only primates to lose their 'fur'. Now, two researchers believe it's the same reason athletes shave off their hair - To become more efficient.
However, in the case of the ancient human it was not a vain attempt to win a gold medal, but a necessity, if they wanted to hunt for food. The theory, derived from advanced computer modeling has been proposed by Professor Wilkinson from Liverpool John Moores University and Professor Graeme Ruxton from the University of Glasgow.
The researchers maintain that the earliest upright humans whose bodies were covered with fur, largely walked or ran only for short distances - Maybe to the nearest tree, to escape a wild animal. That's because humans need to sweat in order to go fast for longer distances - Something that was impossible when their bodies were covered with fur.
As they started to become more proficient hunters and began running longer distances in the hot African Savannah to catch their prey, their bodies began to evolve too - Losing the fur slowly, but surely. A similar theory proposed by another scientist in the 1980's, could not be validated since computer models were not as sophisticated then.
The one thing the researchers cannot accurately predict however, is when we became smooth-skinned. While they estimate it was about 3 million years ago or a million years after we first began to walk upright, to get the exact date, they would have to find an ancient human buried under volcano ash - The only thing known to preserve hair!