Читать книгу Anthropology For Dummies - Cameron M. Smith - Страница 72

Scientists first began to systematically classify living things in the 1700s according to a system laid out by Swedish naturalist Carolus Linnaeus, inventor of Linnaean Classification. Linnaeus noted (obviously enough) that many life forms had anatomical and (in the case of animals) behavioral similarities to other life forms, and he began grouping them according to those similarities. Dogs and horses, for example, shared the characteristic of having hair-covered skin and suckling their young; although dogs and horses are different in many other ways, those characteristics made dogs and horses more similar to each other than either was to some other life forms like fish. Despite their differences, dogs and horses are both mammals. Anatomical similarity is still the basis of life-form identification, but genetic data increasingly factor in as well.

The four main levels of the hierarchical classification system used today are significant to understanding primates:

 The order: All primates are in the Primate order, which is different from the order Canidae (the dogs and dog-like animals), the order Felidae (all the cats, from lion to Tom), and so on.

 The family: The Primate order contains several families of primates, including the Pongidae (chimpanzees, gorillas, and orangutans), the Hominidae (humans and our ancestors), and the Colobinae (the primates of South America).

 The genus: Several genera (plural of genus) are members of the Primate order, including the genus Papio (the baboons) and the genus Homo (humans and their ancestors).

 The species: About 200 species of primates exist. If two individuals are sexually viable (can interbreed and have healthy offspring that themselves can have healthy offspring), the two individuals are in the same species.

Humans, then, are in the order Primate, the family Hominidae, the genus Homo, and the species sapiens. Subspecies designations exist as well, and all humans today are in the subspecies sapiens. Therefore, humans are Homo sapiens sapiens, whereas Central African chimpanzees are in the genus Pan, and the species troglodytes; they’re known as Pan troglodytes.

Today’s fossil and genetic records allow us to reconstruct the evolution of the primate order. This includes about five major adaptive radiations (see the sidebar “You can’t go home again”). In those ancient events, older forms became extinct, replaced by new forms of primates. These radiations include the origins of the primate focus on vision as the most important sense (as opposed to olfaction, or smell, in many mammals), and the origins of the prehensile tail, used to aid climbing among South American primates. Other such radiations are still being discovered.