What separates humans from chimps and other apes?

        Science | Evolution

A Planet Where Men Evolved from Apes?
A gorilla warms himself in the London Zoo's Gorilla Kingdom. See more pictures of primates.

Physically, apes are virtually superheroes compared to us. For example, chimpanzees are roughly four times more powerful than the average human [source: ScienceDaily]. While humans lack the sheer power of the mighty chimp, our nervous systems exert much more control over our muscles, enabling us to execute far more subtle movements.

Humans possess superior motor control, less body hair and a far more advanced brain. Neuroscientists have identified substantially more intricate nerve connectivity in the human brain, as well as some things called spindle neurons. Also known as Von Economo neurons (VENs), these cells appear most frequently in areas of the brain associated with social emotions.

Under "social emotions," you'll find a whole Pandora's box of human characteristics, including empathy, guilt and embarrassment. The consensus is that although humans have evolved socially from our last common ancestor, chimps have remained largely the same. Our two species still share such bloody traits as male kin bonding and lethal territorial aggression. Human males and females, however, share a deeper conjugal bond, creating family-based society. Chimps, on the other hand, have separate male and female hierarchies.

Such differences depend on often slight genetic details. While human and chimps share similar gene sequences, copy number variations can differ greatly. These include code repetitions, deletions and backward sequences. If we were to compare it to something as simplistic as human names, on one hand you have the name "Jim Morrison," which is different from "Jim Jim Morrison," Morrison Jim" or the Doors front man's anagram pseudonym, "Mr. Mojo Risin.'" Among humans, copy number variation can distinguish one identical twin from another and have also been associated with various diseases, such as AIDS [source: Fox]. In other words, it's not just what the genes are, but how they're expressed.