this is interesting

excerpts from the times:

"walking on all fours with the ancestors"

5 brothers and sisters who can only walk naturally on all fours are being hailed as a unique insight on human evolution, after being found in a remote corner of rural Turkey....

apparently it's a genetic abnormality, and it provides insight into how our ape-like ancestors moved.

nick humphrey, evolutionary psychologist at the LSE, who visited the family, said that the siblings appear to have reverted to an instinctive form of behavious encoded in the brain, but abandoned during the course of evolution.

"i do not think that they were destined to be quadrupeds by their genes, but their unique genetic make-up allowed them to be." professor humphrey said. "it is physically possible, which no one would have guessed from the human skeleton."

prof humphrey, who has been contributing to a BBC program, "the family that walks on all fours, said that weeks of study, and factors such as their hands' shapes and callouses, showed that this was a long-term pattern of behavious and not a hoax. "However they arrived at this point, we have adult human beings walking like their ancestors several million years ago."

whil prof humphrey said that cultural influences in their upbringing may have played a crucial role, with parental tolerance allowing the children to keep quadrupedal walking, others believe the cause is more genetic.

jenna harrison: "they walk like animals and its very disturbing at first. but we were also very moved by the family's tremendous warmth and hospitality."