Scientists’ reactions have ranged from deep skepticism to interest in a report of a mutation that makes people walk on all fours, cited in a Turkish study as a possible instance of “backward evolution.”

The bizarre case, reported last week in World Science, has also drawn attention from several scientists in Europe, some of whom are collaborating on a BBC documentary on it.

Three researchers with the University of Cambridge, U.K., and the London School of Economics wrote recently that the case could represent a “rediscovery” of a walking style much like that of human ancestors.[See PDF]

This might help resolve a debate over how our forebears walked, they added.

The mutation is documented only in five members of a Turkish family, whom researchers also describe as mentally and verbally underdeveloped.

Uner Tan of Cukurova University Medical School in Adana, Turkey, has also studied them. Going further than the British researchers, he has claimed they might represent “backward evolution,” citing what he called their ape-like gait and primitive language. …

Several researchers disputed the idea that the syndrome might represent reversion or backward evolution. The claim is “untestable,” wrote Henrique Teotónio, an evolutionary geneticist at the Gulbenkian Science Institute in Oneiras, Portugal, in an email.