In 2005, scientists discovered in Hungary several families, where some adults moved on all fours. It is difficult to identify the causes of this rare disease called Unertan syndrome. Some scientists suggest that the four-legged people just never learned to walk upright because of the lack of training and access to appropriate medical care. Others believe that these families were subjected to mutations in genes that lead people to walk in an upright position.
Although the family lived in isolated villages of 200 to 300 km from each other and had no tribal relations, scientists expect to detect common genetic mutation implicated in this condition. What was their surprise when they found that it is not.
In typical development of bipedalism section of the chromosomes of similar damage was found. Although scientists do not despair, because all the victims were born from marriages within the family and had a characteristic delay of development in infancy. Due to the lack of qualified medical care in early childhood, when possible hypoplasia of the cerebellum, these individuals did not move from walking on all four limbs for walking upright. Although this theory is undeniable, because some families tried to ask for help and to cure disease, but to no avail.
The opening is interesting from the other side that bipedalism is still considered an inseparable feature of the modern man.