The most dramatic divergence between humans and other primates can be found in the brain. Our brains are three times larger, have many more cells, and one gene involved in the production of dopamine was highly expressed in human neocortex and striatum but absent from the neocortex of chimpanzees.

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The most dramatic divergence between humans and other primates can be found in the brain. Our brains are three times larger, have many more cells, and one gene involved in the production of dopamine was highly expressed in human neocortex and striatum but absent from the neocortex of chimpanzees.