A Wrist-Walker Exhibiting No “Uner Tan Sydnrome”: A Theory for Possible Mechanisms of Human Devolution Toward the Atavistic Walking Patterns

Unertan Syndrome: A Case Series Demonstrating Human Devolution

“…However, these structures were nearly normal in the affected individuals of the second family (Tan, 2006b). Moreover, the cerebro-cerebellar structures were completely normal in the MRI scans of an individual exhibiting only the main symptom of the UTS, that is, habitual walking on all four extremities without any mental disturbances (Tan, 2007). The integrity of the vestibular system has not been studied thus far in those affected with the DES.…”

“…Interestingly, all of these families were consanguineous, suggesting that the UTS may be an autosomal recessive disease. A variant of this syndrome has also been recently published (Tan, 2007), which involved a single case without intra-familial marriages, and only expressed the main feature of the UTS, that is, walking on all four extremities.…”

“…Apparently, the asymmetrical cortical motor system controlling the lateral balance cannot complete its development in some children, resulting in a failure in transition from quadripedality to bipedality. This may be genetic and/or environmental in origin (see Tan, 2007). The simplification of the cortical gyri observed in the MRI scans of individuals with the UTS supports the cerebral, not cerebellar, origin of quadripedality.…”

“…Thus, the qudripedal walking pattern may be a normal walking style for some otherwise normal individuals, as a variant of the UTS. An individual with normal mental capacity and a quadripedal gait and no intra-familial marriage between parents has recently been reported by Tan (2007).…”

Üner Tan Syndrome: Review and Emergence of Human Quadrupedalism in Self-Organization, Attractors and Evolutionary Perspectives

“…Atavism, or evolutionary throwback, was defined as "the reappearance of a 'lost character' (either morphological or behavioral) that was typical of remote ancestors" (Tomic & Meyer-Rochow, 2011). This definition is relevant to human quadrupedalism, which is not only one of the main symptoms of UTS, but it can also be observed in individuals with entirely normal brains (Tan, 2007a;Tan & Tan, 2009). Accordingly, the cases with the novel syndrome were first reported as live cases for backward evolution in human beings (Tan, 2005d;Tan, 2006a, b, c).…”