Human brains exhibit more plasticity, the tendency to be modeled by the environment, than chimpanzee brains. Researchers at Georgia State University, the George Washington University and The University of Texas MD Anderson Cancer Center suggest that this plasticity may account for part of human evolution. These findings could also have important implications regarding human susceptibility to degenerative diseases.
The researchers studied 218 human brains and 206 chimpanzee brains to compare two things- brain size and organization as related to genetic similarity. The study found that human and chimpanzee brain size were both greatly influenced by genetics.
‘Brain organization of chimpanzees is highly inherited, but this is not the case with human beings. Researchers observed that anatomy of the chimpanzee brain is more strongly controlled by genes than that of human brains, thus suggesting that the human brain is extensively shaped by its environment.’
In contrast, the study findings related to brain organization revealed key differences between chimpanzees and humans. In chimpanzees, brain organization is also highly inherited, but in human beings this is not the case.
Lead author Aida, postdoctoral scientist at the George Washington University Center for the Advanced Study of Human Paleobiology, said, "We found that the anatomy of the chimpanzee brain is more strongly controlled by genes than that of human brains, suggesting the human brain is extensively shaped by its environment no matter its genetics."
William Hopkins, professor in the Neuroscience Institute at Georgia State, said, "Though our findings suggest that the increased plasticity found in human brains has many benefits for adaptation, it is also possible that it makes our brain more vulnerable to many human-specific neurodegenerative and neurodevelopment disorders."
The study is published in the Proceedings of the National Academy of Sciences