An extraordinary family who walk on all fours are being hailed as the breakthrough discovery which could shed light on the moment Man first stood upright.

Scientists believe that the five brothers and sisters found in Turkey could hold unique insights into human evolution.

The Kurdish siblings, aged between 18 and 34 and from the rural south, ‘bear crawl’ on their feet and palms.

Study of the five has shown the astonishing behaviour is not a hoax and they are largely unable to walk otherwise.

Researchers have found a genetic condition which accounts for their extraordinary movement.

And it could provide invaluable information on how humans evolved from a four-legged hominid into a creature walking on two feet.