It may be hard to spot the human in a ring-tailed lemur at your local zoo, but science considers him one of your distant cousins -- along with gorillas, chimps and other members of the prestigious primate order of mammals. A penchant for travel separated the lemur species from the rest of its relatives along the evolutionary journey. However, there’s enough monkey in the lemur to keep it on the invitation list for primate family reunions.
Scientists believe lemurs -- or prosimians, meaning “before the monkeys” -- left the southeast coast of Africa by climbing aboard floating logs and other vegetation that eventually deposited them on Madagascar and the nearby Comoros islands in the Indian Ocean. Fossilized remains and European traveler accounts indicate the isolated Madagascar immigrants once included lemurs as large as gorillas, such as the 350-pound archaeoindris. The arrival of humans on Madagascar, subsequent habitat destruction and pet trade over the past 2,000 years have reduced the population to 88 known species, according to the Smithsonian National Zoological Park. Modern lemurs range in size from the 1-ounce pygmy mouse lemur to the 15-pound diademed sifaka (Propithecus diadema).
The nearest relatives to the lemurs are other prosimian primates, which include galagos, often referred to as “bush babies” because of their human, infant-like vocalizations. These small omnivores (topping the scales at about 5 ounces) originate in the African rainforest. Tarsiers, another group of pint-sized prosimians hailing from Southeast Asia, are nocturnal primates with large eyes and a spinal configuration that allows them to turn their heads nearly 360 degrees. Lorises (identified as slow, slender or pygmy) also claim a spot on the prosimian branch of the primate family tree. The pygmy loris makes its home in southeast Asia, and the slender loris is confined to southern India. The slow loris boasts the largest range, which includes the forests of Indonesia, Malaysia and the Philippines, among others.
Science divides the monkeys into "new world" and "old world" categories. The 78 species of old world primates come from Africa, Asia, the Middle East and Spain and include several varieties of baboons and the macaque monkeys of Japan. New world monkeys populate Mexico, Central America and South America. These nearby neighbors include several familiar zoo species, such as spider monkeys, howler monkeys and squirrel monkeys.
Identified as lesser apes (gibbons and siamangs) or great apes (bonobos, gorillas, chimpanzees and orangutans), apes are the most distant primate relatives of the lemur, other than humans. An ape’s lack of a tail, its ability to recognize itself in a mirror and its intellect, including purposefully communicating with humans via sign language, help separate him from the monkeys and prosimians.
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