So Is This Family the Missing Link ? They Walk on All Fours like Apes. Are They, as Some Scientists Believe, an Amazing Throwback to Our Primitive Ancestors - or Just a Tragic Case of Medical Neglect?
Byline: JONATHAN FOREMAN
THEIR affliction is grotesque, disturbing, and like something out of a Victorian freak show. They crawl on hands and feet like animals, but with the swift agility of circus gymnasts. Their speech is a primitive babble.
But scientists believe these siblings from a Turkish family, apparently condemned to walk on all fours by a combination of birth defects, genetic damage and lack of medical care in infancy, may offer startling clues to the process of human evolution - and the days when our ape-like ancestors first began to walk upright.
The Ulas family, who live in a remote Kurdish area of southeastern Turkey, are the subject of a controversial new BBC programme that features convincing film footage of five brothers and sisters 'bear crawling' on their hands and feet.
And a Turkish scientist quoted by the programme goes so far as to claim that the family are some kind of genetic throwback, a 'missing link' to our pre-human ancestors.
Uner Tan, of Cukurova University Medical School, believes the family represent a case of what he calls 'backwards evolution'. He says the children's quadrupedal gait, primitive language and impaired hand skills are all throwbacks to our ape-like ancestors.
Astonishingly, he declares: 'This syndrome can be considered a live model for human evolution.' Other scientists quoted in the programme are also convinced that the Ulas family are a goldmine for research.
Dr Stefan Mundlos, a genetics professor at the Max Planck Institute in Berlin, who has studied the Ulas family's DNA, believes the damaged gene they all share may hold the key to humanity's evolutionary shift to upright walking.
Still more scientists hope that the family's peculiar four-limbed walk will reveal valuable information about the ways quadrupedal movement affects the skeletal system, making it easier for us to interpret fossil information about our simian ancestors.
PROFESSOR Nicholas Humphrey, who teaches evolutionary psychology at the London School of Economics is convinced the way the Ulas children move echoes an ancestral gait.
He says it indicates that our ancestors walked on their palms rather than their knuckles - a subject of intense debate by palaeo-anthropologists.
So what is the truth? Can this family from the distant shores of Turkey really shed light on our past? Or are they simply suffering from a mental disability which reveals nothing more than a desperate lack of medical care?
The five afflicted men and women - disturbingly referred to as 'males' and 'females' by the scientists and programme-makers - are aged between 18 and 34 and come from a family of 19 children.
Their parents are closely related - there is no doubt they are the result of more than one generation of inbreeding - and all of the children are severely disabled. As Uner Tan claimed when he first came across them: 'They had a rather primitive language.
'They were mentally retarded; they could not count from one to ten. They were not aware of time and space. For instance they do not know where they live - which country, which village, which city.
'Their sitting posture was rather similar to an ape. Their head posture was rather similar to the head posture of our close relative, the chimpanzee.
They could stand up, but only for a short time, with flexed knees.' The scientists explain that the reason they walk on all fours is a rare genetic condition called cerebellar hypoplasia. This means a key part of the brain is underdeveloped and, as a result, they lack the co-ordination to walk upright.
DNA analysis of the afflicted children shows that they all have damage to the genes on chromosome 17p. Professor Mundlos believes this chromosome may be the one that controls upright walking.
He argues that the failure of this chromosome means another, more primitive chromosome within the genetic code is activated - a chromosome that our ape ancestors had and one that was responsible for four-legged walking. …