Chimpanzees, gorillas, orang-utans, and over a hundred more of the 234 known primate species are threatened with oblivion, and more than another 40 are in danger. The threats range from the felling of forests to the pet trade, from the cooking pot to medical research.
When homosapiens first emerged it and its closest relatives formed just "a minor branch on the primate family tree." It was not until 1930 that our population outstripped those of all our relatives put together.
The deaths in the family began long before. At least 15 primate species became extinct within 500 years of people first setting foot in Madagascar a thousand years ago. Two thirds of its species of lemurs are now on the brink of disappearance.
Orang-utans have lost over 80 per cent of their habitat in Malaysia and Indonesia in just 20 years. In Brazil, 11 of their 12 unique primate species are on the edge of extinction. Felling ancient Japanese forest has driven macaques into neighbouring farmland in search of food.
Forest and other habitat loss may be the main threat, but hunting runs it a good second. Apart from chimpanzees humans are the only primates that routinely kill their relatives for food. Millions of pounds of monkey meat is eaten in Africa each year, while a family of Brazilian rubber tappers accounts for 380 large primates in 18 months.
Although most countries have outlawed trade in endangered species, charismatic primates like gibbons, chimps, gorillas and orang-utans are still smuggled for pets. A television show in Taiwan in the late 1980s, starring an orang-utan, caused such demand that up to five per cent of the ape's wild population was sold to fans through newspaper advertisements.
Tens of thousands of chimpanzees, with which we share 98.4 per cent of our gene pool, were taken from the wild for medical research between the 1950s and 1980s.
There are hopeful stories to lighten the gloom. Villagers created their own sanctuary for howler monkeys in Belize, and the gorillas made famous by David Attenborough were protected during the Rwandan civil war: only two were killed, by accident, throughout the conflict.