CHAPTER 7: THE LIVING PRIMATES
The Order Primates contains 238 species found throughout the tropical areas of Africa, Asian and North and South America, although some species have adapted to temperate climates. Most are arboreal. Several hypotheses have been put forth to explain the origin of the primates, including emphasis on leaping patterns of locomotion, consuming fruits growing at the ends of branches, and insect predation.
Living primates are characterized by flexible hands and feet, usually with five digits that end with flattened nails instead of claws. In some cases the thumb is truly opposable. The hands and feet are covered with tactile pads with epidermal ridges that support a refined sense of touch. This flexibility of the hand, along with flexibility in the shoulder and arms, facilitates movement through the trees as well as manipulation of the environment.
The sense of smell is reduced in primates, but the sense of vision is greatly enhanced, being both stereoscopic and in color. We can identify two major groups of primates: the strepsirhine primates have a rhinarium and philtrum in the nasal region while the haplorhine primates lack these features. Primates have relatively long gestation, infantile and juvenile periods, and long life spans. They possess large brains and are highly intelligent. Living in large social groups, they adapt largely by means of complex, learned behavioral patterns.
This chapter described the major groups of living primates, including the lemuriformes, tarsiers, New World monkeys, and Old World monkeys, as well as the living apes, the gibbon, orangutan, gorilla, chimpanzee, and bonobo. In the following chapters, their anatomy, behavior, and evolutionary history will be explored.
