%A Prof. Dr. Uner Tan %J International Journal of Neuroscience %T A NEW SYNDROME WITH QUADRUPEDAL GAIT, PRIMITIVE SPEECH, AND SEVERE MENTAL RETARDATION AS A LIVE MODEL FOR HUMAN EVOLUTION %X The author has discovered a new syndrome with quadrupedal gait, flexed head and body, primitive speech, severe mental retardation, and mild cerebellar signs with a disturbed conscious experience. This syndrome was exhibited by 5 of 19 children from a consanguineous family. The pedigree demonstrated a typical autosomal-recessive inheritance. The genetic nature of this syndrome suggests a backward stage in human evolution, which is most probably caused by a genetic mutation, rendering, in turn, the transition from quadrupedality to bipedality. This would then be consistent with theories of punctuated evolution. On the other hand, the extensor motor system causing a resistance of the body against the gravity may actually be subjected to evolutionary forces. This new syndrome may be used as a live model for human evolution. %K erect posture, evolution, human, quadrupedal gait %P 361-369 %E Sir Sidney Weinstein %V 116 %D 2006 %I Taylor & Francis %L cogprints4941