When you buy through data link on our site , we may earn an affiliate commission . Here ’s how it cultivate .
When Turkish evolutionary biologist Uner Tan introduced the humans to a Turkish family unit with some appendage who could walk only on all fours , in a " bear crawl , " he and other scientists chew over this unmatched gait was the resurgence of a trait miss during human evolution .
Not so , a new subject area obtain .
A person with Uner Tan Syndrome walks on all fours.
The family and other people with Uner Tan syndrome do not represent " a backward stage inhuman evolution , " as Tan write in a 2006 newspaper in the International Journal of Neuroscience , said Liza Shapiro , a professor of anthropology at the University of Texas at Austin . In raw research , Shapiro and her fellow worker compare videos of the house ’s pace with the gaits of nonhuman primates , such as chimpanzees or gorillas . They ground the gait patterns did not equalise . Instead ofrecreating copycat paseo , multitude with Uner Tan are but adapting to their upset , Shapiro and her workfellow reported July 16 in the journalPLOS ONE .
On all quartet
Tan first remark the syndrome that now wear his name in a family of 19 living in rural southerly Turkey . Five of the menage members walk using their foot and hands , and also have cognitive disabilities . The house was the subject of the 2006 BBC2 infotainment , " The Family That Walks on All Fours . "
inquiry has since revealed that the disorder is due to a genetic mutation on chromosome 17 , which affects thecerebellum , part of the mentality creditworthy for apparent motion and balance . From the beginning , Tan ’s statements about the evolutionary nature of the touched family ’s walk patterns were controversial . The affected nipper never had physical therapy or adaptive engineering such as wheelchairs , produce their gait a requisite . [ See a video recording of walk on all fours ]
But no one ever challenged the primary call : that the moved child walked like nonhuman primates . primate that take the air on all quatern do so other than than most other mammals , Shapiro say Live Science . Primates take the air in a diagonal sequence , putting down a hind branch and then the opposite front limb : left metrical foot , correct hand , right foot , left mitt .
Most other mammals walk in a lateral sequence , with the same - side limbs keep up each other : pull up stakes foundation , left hand , right foot , ripe script . Human babies and adults asked to " bear crawl " on hands and infantry typically take the air in a sidelong successiveness , too , Shapiro suppose .
adapt , not devolving
Shapiro said she became concerned in studying the gait of people with Uner Tan Syndrome in 2006 after seeing the documentary on the Turkish house .
" It was all about whether or not it wasevolutionary reversal , which kind of appal me , " she said . Immediately , though , she could see that the family was not using the primate diagonal gait .
Shapiro did not have access to practiced video of the category ’s walk patterns until recently , when one of her co - authors told her he had footage from the BBC . From that telecasting , she and her colleagues were able to canvas more than 500 pace made by the five sept members with the upset .
About 99 percent of the strides were sidelong , not diagonal — a reversal against the notion that the menage members had " rediscovered " anancestral archpriest way of walking . Instead , they were walk like any distinctive adult would if take to move on hands and substructure .
A lateral gait is ready to hand for long - limbed animals ( such as humans ) when walking on all fours , she said , because it helps keep the limbs from knock into one another .
" They ’re doing what any human does in that situation where they ca n’t stand up , " Shapiro tell .
Shapiro emphasize that even if the family had moved with a slanting gait , the traffic pattern would not bear witness anything about human evolution or the origins of bipedalism .
" Bipedalism necessitate a peck of change , physical and anatomical change in the body , " she said . " Neurological changes . Motor changes . It ’s not just one matter . "
