What are primates?
The system we have of naming and ordering biodiversity dates from the work of Carolus Linnaeus in the 1700s. It is from this work that we have the bionomial naming convention of genus and species (Fleagle, 1999). For example, modern humans, which are part of the primates group, are classified as follows:
(adapted from Fleagle, 1999: 6-7)
Primates are our closest living relatives. Primates are a diverse group ranging in size from the tiny pygmy mouse lemur (Microcebus myoxinus) at around 30 g in weight to the formidable male gorilla at over 175 kg (Fleagle, 1999).
Depending on how a species is defined, there are approximately 200 - 230 species of primate alive today (Cowlishaw and Dunbar, 2000: 8). There are four major divisions in the order Primates: Apes, Old World Monkeys, New World Monkeys and Prosimians. Primates have adapted themselves to live in a variety of habitats (Fleagle, 1999). The Old World is considered to be Africa, Asia and Europe; the New World primates are found in southern Mexico and Central and South America (Dolhinow and Fuentes, 1999).
Generally, primates share these common characteristics:
- a shortened snout
- a non-specialised skeleton, with hands and feet of five digits
- opposable thumbs
- nails instead of claws
- relatively large brains in relation to body size
- extended developmental periods, both ante- and post-natal, with a significant maternal investment and a long period of socialisation
- an increased reliance on vision rather than scent
(from Cowlishaw and Dunbar, 2000).
Different species have different environments (e.g. forests, woodlands, savannahs, and high-altitude grasslands) (Eeley and Lawes, 1999); diets (e.g. fruit, leaves, insects, gums, eggs) (Fleagle, 1999); social structures (e.g. monogamous families, polyandrous groups, polygynous groups, and multi-male multi-female groups) (Kappeler, 1999); activity patterns (e.g. diurnal, nocturnal, crepuscular and cathemeral) (Fleagle, 1999); and locomotion (e.g. arboreal quadrupedalism, terrestrial quadrupedalism, leaping, suspensory behaviour such as brachiation, and bipedalism) (Fleagle, 1999).
Apes are divided into two groups. The gibbons and siamangs of South East Asia are the lesser apes. They use brachiation as their primary locomotion (Dolhinow and Fuentes, 1999). The great apes are orangutans, chimpanzees, bonobos, gorillas and humans. Orangutans are found in Borneo and Sumatra (Knott and Kahlenberg, 2007); chimpanzees and bonobos are found across equatorial Africa (Stumpf, 2007); gorillas are found in ten countries across central Africa (Robbins, 2007); and humans are to be found in almost all areas of the world! They are larger and heavier than other primates, with relatively larger brains. Apes have no tails. (Dolhinow and Fuentes, 1999).
Old World Monkeys
These are found in Africa, Asia and Europe. They are usually larger than New World Monkeys. They include baboons, macaques, the brilliantly coloured mandrills, mangabeys, guenons, vervet monkeys, colobus monkeys, leaf monkeys, langurs and the remarkable proboscis monkeys (Dolhinow and Fuentes, 1999).
New World Monkeys
These are found in southern Mexico, Central and South America. They include marmosets, tamarins, Goeldi's monkeys, titi monkeys, capuchins, squirrel monkeys, sakis, spider monkeys, woolly monkeys, owl monkeys (the only nocturnal anthropoids), the startling uakaris and the fabulously noisy howler monkeys (Dolhinow and Fuentes, 1999).
Prosimians have retained some "primitive" features such as a moist nose (like dogs). They are all nocturnal except for lemurs. Many have specialized glands used for communications and territory marking. As well as lemurs, they include lorises, pottos, galagos and tarsiers (Dolhinow and Fuentes, 1999).