As per scientists, a ‘genetic accident’ which occurred around 500 million years ago was the origin of intelligence when the genes that enabled humans to think and reason evolved.
As per new findings, intelligence in humans developed as the result of an increase in the number of brain genes in our evolutionary ancestors.
Scientists also believe that the same genes that improved our mental capacity are also responsible for a number of brain disorders.
The findings say that a simple invertebrate animal living in the sea 500 million years ago went through a ‘genetic accident’, which led to formation of extra copies of these genes. These extra genes benefited the descendents of this animal which gave rise to behaviorally sophisticated vertebrates – including humans.