Gene Mutation Linked To Cognition Is Found Only In Humans

Science Daily — The human and chimpanzee genomes vary by just 1.2 percent, yet there is a considerable difference in the mental and linguistic capabilities between the two species. A new study showed that a certain form of neuropsin, a protein that plays a role in learning and memory, is expressed only in the central nervous systems of humans and that it originated less than 5 million years ago. The study, which also demonstrated the molecular mechanism that creates this novel protein, will be published online in Human Mutation, the official journal of the Human Genome Variation Society.

Led by Dr. Bing Su of the Chinese Academy of Sciences in Kunming, China, researchers analyzed the DNA of humans and several species of apes and monkeys. Their previous work had shown that type II neuropsin, a longer form of the protein, is not expressed in the prefrontal cortex (PFC) of lesser apes and Old World monkeys. In the current study, they tested the expression of type II in the PFC of two great ape species, chimpanzees and orangutans, and found that it was not present. Since these two species diverged most recently from human ancestors (about 5 and 14 million years ago respectively), this finding demonstrates that type II is a human-specific form that originated relatively recently, less than 5 million years ago....

http://www.sciencedaily.com/releases...0508072829.htm

So this is what sets us apart.