New Species--Keep On Counting!
No, not freaks of nature. Rather, new species that scientists have never--ever--laid eyes on before. From Vietnam to the African Congo, scientists are now sighting about 13,000 new species every year. Like detectives combing for hidden clues, scientists may be gathering new evidence to the unsolved mystery of life's diversity, and doing so at the fastest rate in history.
After more than 200 years of counting and cataloguing, scientists have identified roughly 1.4 million species on Earth. But their best collective guess is that anywhere from 4 to 40 million species of animals, plants, fungi, bacteria, and other organisms may still lurk undiscovered in remote spots like New Zealand forests or the savage Himalayan mountains. Their guess is actually based on a mix of scientific formulas and prediction. Most large mammals, for instance, are believed to have been discovered while many smaller animals--tiny mammals, beetles, and mites--are still thought to exist in the wild, unknown.
What is a species, anyway? Taxonomists (scientists who categorize all life on Earth) define a species as a group of living organisms--bacteria, insects, or fish, for example--that breeds only with others identical to itself. All members of a species share the same general appearance and behavior. Currently more than 4,000 mammals (warm-blooded, milk-drinking vertebrates), for example, have been identified by taxonomists (at least 88 of those have already gone extinct, or died off). But the final mammal count may double before the species counting game is over. "We may think we know what lives on the face of the Earth, but we really don't," says Niles Eldredge, a curator at the American Museum of Natural History in New York City.
Why are scientists suddenly hot on the trail of new species? Groups such as the World Wildlife Fund and Conservation International have rushed crack teams of biologists to collect information about remote regions--before bulldozers and chain saws deforest them, mine them for minerals, or turn them into grazing lands. A campaign called the rapid assessment program (RAP) targets isolated habitats where a rich diversity of species may have evolved beyond the eyes of man.
Two years ago, for instance, scientists scouring mountain jungles on the border of Vietnam and Laos came across 18 animal skulls, the remains of a deer-like species they couldn't identify. The skulls had antlers that looked unlike any found on deer species known to science. Where did the deer come from? Native forest-dwelling hunters informed the scientists of an uncounted population of "mystery" deer alive and hidden amid high mountain peaks. "This is a lost world, a place we haven't ventured into in hundreds of years," says Vietnamese biologist Pham Mong Giao, who worked on the project.
The distinctive antlers found on the skulls perfectly matched the antlers of the live deer photographed in the mountains. Presto! Scientists had come upon a new deer species, now named the Truong Son muntjac. It's one of three large mammals discovered in Vietnam in the last seven years.
Other "hot spots" ripe for discovery of new species include the Philippines, Madagascar, and the Andes Mountains and Amazon River Basin in South America. Endemic species (creatures found nowhere else), such as the black-headed sagui dwarf recently found in the Amazon rain forest, are like poster kids for environmentalists.
"Biologists are using new species to highlight the urgency of deforestation," says Leeanne Alonso, an entomologist (insect scientist) who leads RAP expeditions. So far, RAP teams have led to the creation of six protected areas totaling millions of acres in five countries.
Put to the Test
One tool scientists use to identify new or distinct species is DNA-testing. DNA is the genetic code that transmits traits from one generation to the next. In fact, about two-thirds of all "new" species can only be identified by biologists conducting DNA tests.
For example, ornithologists (bird scientists) used to lump the fluffy brown screech owls found separately both in the Comoros Islands and in Madagascar into a single species called Madagascar scops owl. After all, the two sets of birds, found years ago, looked identical. Nonetheless, scientists recently tested the owls' DNA. Guess what? One island's owl has markedly different DNA from its neighbor. They'll now be catalogued as two species: Madagascar scops owl and Anjouan scops owl.
Briefly, here's how scientists use DNA tests: The DNA molecule is shaped like a twisted rope ladder; it's often called a double helix. The "rungs" of the ladder consist of four chemical compounds called base pairs. If the genetic codes spelled out in the base pairs don't match closely enough between two animals that may look like twins, scientists conclude they've found a new or distinct species.
South America's four-eyed opossums, for example, are now divided into as many as four different species. "Fifty years ago, scientists took things that were different and threw them together," Niles Eldredge says. "Today the trend is to split them back up."
Race Against Time
Biologists in search of new species are racing against time. Their mad dash to identify new species and protect them may not come fast enough to save their discoveries from extinction. Many species--like the saola, a wild ox found seven years ago on the border of Laos and Vietnam--are threatened as soon as they're discovered because their habitats are disappearing. "When you clearcut a forest, you don't know what's in there," says Alonso. "One hundred species can be wiped out in a day."
The natural extinction rate that existed for millions of years before humans evolved claimed about two species per year. Today, 1,000 species vanish each year, according to the World Conservation Union.
"We have reason to be worried," says ornithologist Tom Schulenberg of Chicago's Field Museum.
PIRANHA * FOUND: 1996 * WHERE: Bolivia * SIZE: 22 centimeters * FAST FACT: Young piranhas eat floating fruits and seeds. Adults use razor-sharp teeth to devour fish flesh.
SAOLA * FOUND 1992 * WHERE: Laos and Vietnam * SIZE: 1 meter * FAST FACT: May be missing link that reveals how buffalo, cattle, and spiral-horned antelope evolved.
ZOG-ZOG * FOUND: 1997 * WHERE: Brazil * SIZE: 40 centimeters long, from head to tail * WEIGHT: 1 kilogram * FAST FACT: Couples sing a throaty duet. One of four new monkey species found in a single year in the Amazon region.
PLAND HOOPER * FOUND: 1995 * WHERE: Ecuador * SIZE * 2.5 centimeters * FAST FACT: Sucks sap from leaves and stores it in its upturned snout
SANGHA FOREST ROBIN * FOUNDl 1996 * WHERE: The Central African Republic * SIZE: 8 centimeters * FAST FACT: Ornithologists examined 300 specimens from 89 areas at seven museums before declaring this robin a new species.
AXELROD: FOUND: 1988 * WHERE: Pacific Ocean near New Guinea * SIZE 5 centimeters * FAST FACT: This slime scraper spends its whole life inside coral-reef crevices
BLACK-HEADED SAGUE DWARF * FOUND: 1996 * WHERE: Brazil * WEIGHT: 187 grams * FAST FACT; THE average adult measures just 10.1 centimeters, making it the second-smallest monkey ever found.
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|Title Annotation:||scientists sighting 13,000 new species a year|
|Date:||Feb 8, 1999|
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