Genetically and physiologically, baboons and humans share a number of traits. The sizes and structures of the major organs and tissues have even led to the transplanting of a baboon liver into a human. Unlike most monkeys, baboons exhibit menopause. They respond to stress by releasing stress hormones, and the cells that form blood also behave similarly. Baboons and humans have about 95 percent genetic similarity. Because of such traits, baboons have been used to study obesity, heart disease, epilepsy, and other human diseases.
While there are occasionally attempts to portray the difference between baboons and humans as mainly one of degree, in reality the gulf between humans and baboons is immense. Baboons do not exhibit anything approaching the complexity of human language, culture, or technology. Political structures, religions, use of symbols in languages—these are all foreign concepts to a baboon. Indeed, some religions draw the difference as humans being created in the image of God and having a soul. One might say the difference is that baboons are only governed by instinct, while humans exhibit a spiritual aspect in addition to instinct.
The fact that some scientists consider baboons to be divisible into five or more species, while other scientists consider them to be composed of only one species (and the other types being subspecies) shows the uncertainty and developing nature of scientific inquiry.