A new study shows that a group of humans made famous by a 2006 BBC documentary called The Family That Walks on All Fours are not exhibiting backward evolution to that of our ape ancestors, but have just adapted to this strange means of locomotion due to their brain conditions.
The family from remote Turkey, were discovered in 2005. Their hand walking is seen as a “disability”. Instead, it’s how they adapted to their unique and rare condition.
The conditions is called Uner Tan Syndrome (UTS) and includes severe mental retardation with affected speech. They have trouble walking on two legs and balance with their extra limbs – their hands. Professor Uner Tan thought he found evidence of devolution in the family. This is now discarded based on new evidence.
The concept of devolution or backwards evolution is thrown around especially by Creationists who don’t understand at all how evolution actually works. This throwback concept is deeply flawed. Evolution does not work like a ladder of progression or purposeful direction. Evolution is descent with modification. However, if an organism still carries a genetic adaptation that can be useful, it will be expressed.
The first family was discovered in a small village near Iskenderun, and families were later found in Adana and two other small villages near Gaziantep and Canakkale. In all the affected individuals dynamic balance was impaired during upright walking, and they habitually preferred walking on all four extremities.
The cause of the condition is likely multifaceted and genetic. A high rate of inbreeding may play a role in manifesting the syndrome.
The new research finds that the pattern of walking in UTS carriers is NOT a throwback to the ways apes walked on all-fours but is different. Simply an adaptation, not an atavism.
“Although it’s unusual that humans with UTS habitually walk on four limbs, this form of quadrupedalism resembles that of healthy adults and is thus not at all unexpected,” Shapiro says. “As we have shown, quadrupedalism in healthy adults or those with a physical disability can be explained using biomechanical principles rather than evolutionary assumptions.”
Here is the study:
Another evolution trope is again busted with additional evidence. Science evolves too as our information gets better.
More about this condition: