Earth Science: Biology – Animals – Primates
Primates, in comparison to most other animals, have a large brain with a strikingly enlarged cerebrum. This gives them the capacity to learn and to display complex social behavior.
Nonhuman primates live in the tropical and subtropical forests and savannas of Central and South America, Africa, and Asia.
Most primates are herbivores and live in trees, but some have adapted to life on the ground. They have relatively large brains and enhanced capacity for learning, tool use, and complex behaviors.
Their large, forward-facing eyes let them see sharp detail in three dimensions. They can perceive contrast and color. Their supple hands and feet are adapted to feeling, gripping, and holding.
Communication and social life
Primates have highly developed social lives. They usually live in a family group or a harem—with one male and up to nine females—and they communicate through sounds, gestures, and facial expressions. Excreted chemicals (pheromones) can transmit messages, such as danger warnings or a desire for sex.
Jane Goodall and other researchers have studied the behavior of chimpanzees, investigating their problem-solving skills and their ability to communicate with humans using symbols and sign language. Modern research divides primates into Strepsirrhini (“wet noses”) and Haplorrhini (“dry noses”).
Strepsirrhini tend to be nocturnal, with a smaller body size and keener sense of smell. Haplorrhini are mostly diurnal—active in the daytime—with some exceptions, such as the tarsiers. Strepsirrhini include lemurs, lorises, and galagos. Lemurs only live on the Comoro Islands and Madagascar. Lo- rises and galagos resemble sloths.
Their powerful hands give them a secure grip on tree branches in Africa and South Asia. The Haplorrhini live in the tropical and subtropical zones of the Americas (capuchin mon- keys and marmosets), in Africa (gibbons and great apes), and in South Asia (tarsiers). New World monkeys are found in the Americas, whereas Old World monkeys inhabit parts of Africa and Asia.
GENEALOGY OF PRIMATES
The ancestors of most modern primates emerged as early as 55 million years ago. In the 19th century Charles Darwin, among others, suggested that humans and primates were closely related.
Although some still dispute this theory for ideological reasons, multiple types of scientific studies clearly show a close biological kinship between humans and the great apes (such as chimpanzees, gorillas, and orangutans)