The chimpanzee is, without a doubt, the closest living relative to the human being. With a difference of a little more than 1% in our DNA codes, chimps are in fact genetically closer to humans than they are to gorillas.
The chimpanzee's skeleton matches bone for bone with that of homo sapiens. We also share the same organs and central nervous system. This nervous system, consisting of the spinal cord and brain, is one of many places similarities are apparent.
Like humans, chimpanzees have large brains capable of complex thought and calculations. They are capable of clear, deductive reasoning, and they use and invent tools for more purposes than any other creature on the planet besides humans. Chimpanzees are omnivorous, and while hunting they use complicated teamwork system for capturing prey. They have also been known to use and understand computers.
Another mental capacity is the animal's clear sense of self. A common example of this is that the animal recognizes itself when looking in a mirror. It seems simple enough, yet very few species pass the "mirror test."
But beyond the similarities in the nervous system and brain, the skeletal and muscular similarities are astounding as well. Although they are usually seen as quadrupeds, chimpanzees can walk upright for short distances, just as humans, who are primarily biped, can walk on all fours.
The hands and feet, including four flexible fingers and an opposable thumb, all feature fingernails instead of claws. Chimpanzees are also one of the only other species with friction ridges on their fingers, small lines forming a unique pattern we call a fingerprint.
Both human and chimp eyes are set forward on the head and close together, with clear vision and an increased reliance on depth perception. We both see binocular stereoscopically and in full color.
Although most other mammals rely heavily on a sense of smell, it is diminished in the chimpanzee much as it is in the human.
In contrast to all these similarities, the one real difference anatomically is the chimpanzees' lack of vocal systems, preventing a spoken language. However, chimpanzees in captivity have been successfully taught American Sign Language and communicate readily and easily with humans. One of the first to learn, a female chimp named Washoe, in turn taught her companions and her adopted son. There is no doubt that chimpanzees can learn sign language as well as a any deaf or mute human being.
The evolutionary split from chimpanzees to humans happened about 5 million years ago. However, some have recently proposed adding the chimpanzee to the human (Homo) genus. It has not been formalized, however, the change is still a hot matter of debate.
However classified, the more we learn about and from the chimpanzees, the more we realize how connected we are to each other.