Science: The Truth About... Systematics

CONSIDER THIS: about 10 per cent of all the species that have ever lived since life on Earth began nearly 4 billion years ago are alive today. Out of the estimated 13 million species existing now, only 1.7 million are known to science.

The rate at which species are becoming extinct owing to human activity on the planet is between 1,000 and 10,000 times greater than the average extinction rates it has experienced over the past hundreds of millions of years.

Life on Earth is dying out faster than we can record it. Up to 10 per cent of the species of animals and plants alive today will be history within the next quarter-century. Most of these will become extinct without ever having been described and given names. To quote Edward O Wilson, the great evolutionary biologist, who says it is imperative to finish mapping the biosphere: "The most compelling reason for the broadening of goals is that, unlike the rest of science, the study of biodiversity has a time limit."

Systematics is the name given to the field of biology devoted to discovering, describing, naming and classifying organisms, whether they are living, or extinct fossils. "Without taxonomy to give shape to the bricks, and systematics to tell us how to put them together, the house of biological science is a meaningless jumble," according to Robert May, the distinguished Oxford biologist who has made a study of the world's biodiversity.

Systematics - the naming of animals and plants - may sound boring, but it is essential for learning about how living organisms relate to one another. "By devising a single agreed system of scientific names, it enables people around the world to communicate with each other about the diversity of life on Earth," says the UK Systematics Forum, a group representing the leading British players in the field.

The Natural History Museum in London, which has one of the most extensive collections of animals and plants in the world, argues the case for spending time and money on identifying new species in a report, The Web of Life, which is published this week. "The crucial message that we all depend on a healthy, functioning natural environment has received near-universal support," the report says.

One of the best examples of how systematics can be of immense practical value occurred 10 years ago when the museum was asked to identify the larva of a fly. It turned out to be the New World screwworm, a serious pest in America because of its habit of burrowing into the skin of livestock. What made this identification so important was that the specimen in question had come from Libya, and was the first documented case of the insect appearing in north Africa.

The pounds 50 test to identify the worm triggered a pounds 50m eradication programme to stop the pest gaining a foothold on the African continent. "Although the campaign appeared costly, an independent economic assessment of the costs and benefits of the eradication campaign estimated the return on investment to be in the region of 50:1 for north Africa alone," the museum says.

Mary Gibby, associate keeper of botany at the museum and a member of the UK Systematics Forum, said that the screwworm story is a perfect illustration of the necessity of investing in systematics. There are also untold practical benefits for discovering new medicines and drugs from unknown species of plants and micro-organisms, she adds.

The other important aspect, she points out, is conservation. Since 1992, 70 new species of lichen and more than 100 species of parasitic wasp new to Britain have been recorded. "You've got to identify what you've got before you can work out how to protect it," Dr Gibby says.