A study led by scientists at the University of Edinburgh reveals for the first time the moment in history when human beings gained the ability to think, learn and analyze different conditions.
It has been determined that human genes' evolution to a level where thinking was enabled dates to over 500 million years ago, EurekAlert reports.
Scientists believe that the intellectual evolution was initially caused by a “genetic accident,” which is supposed to have occurred 500 million years ago in invertebrate creatures. The event is defined through an augmentation in the amount of brain genes the latter possessed.
This moment caused a shift in the natural evolution, leading to a separation of creatures according to the number of brain genes developed. Thus, humans got to separate themselves from the beings that were unable to perform reasoning actions.
The study also unveils a strong bond between the evolution of intelligence and the development of brain dysfunctions, proving that both of them are determined by the same type of genes.
“Our work shows that the price of higher intelligence and more complex behaviors is more mental illness,” declared Seth Grant, professor at the University of Edinburgh.
Researchers based their study on an experiment involving mice and humans in a comparative analysis of their intellectual abilities.
The experiment first consisted of having both mice and humans recognize objects pictured on a screen. Afterwards, these observations were related to genetic information taken from the genes of the two breeds.
It was proven that the same genes are in charge of mental abilities in humans and mice. Moreover, scientists discovered that the genes' alteration led to the deterioration of advanced mental skills.
“Our work shows that the price of higher intelligence and more complex behaviors is more mental illness,” Prof. Grant declared.
Scientists believe that the discovery brings a significant contribution to treatment of behavioral dysfunctions caused by gene mutation.
“This ground breaking work has implications for how we understand the emergence of psychiatric disorders and will offer new avenues for the development of new treatments,” declared John Williams from Wellcome Trust's department of Neuroscience and Mental Health.