Saturday :: Mar 20, 2004

Mass Extinction Underway


by Mary

Two new biological studies in Great Britian show species disappearing at record rates leading scientists to believe we are in one of the periods of mass extinction. Biologists found in Great Britain that butterfly species were going extinct a rate faster than birds, a result that was surprising and alarming.

The researchers found that populations of 71 percent of the butterfly species have decreased over the last 20 years, compared to 56 percent for birds and 28 percent for plants. Two butterfly species (3.4 percent of total) became extinct, compared to six (0.4 percent) of the plant species surveyed. None of the native breeding birds went extinct in the last 20 years.

Crucially, the decline in populations happened in all the major ecosystems and was distributed evenly across Britain, rather than in just a few heavily degraded regions.

The crisis could be foreshadowing a sixth mass extinction, warn the researchers. Life on Earth has already seen five mass extinctions in its four billion year old history. The last one, which wiped out the dinosaurs, happened 65 million years ago at the end of the Cretaceous period and was possibly caused by a giant meteor collision.

The current extinction is being precipitated by the widespread loss of habitats because of human activity, according to Tefler. The remaining habitats are small and fragmented, and their quality has been degraded because of pollution.

Plants species are also disappeaing, and a second study links the problem to nitrogen pollution. Nitrogen pollution is the result of coal burning power plants and in locations where the fallout from the power plants is minimized, the variety of plant species is significantly higher than areas that have experienced years of pollution.

Stuart Pimm, a leading conservation biologist at Duke, ties these new reports with other studies that show the loss of diversity throughout the world, including depleted fish stocks in the oceans, the dying coral reefs, the deforestation crisis in the Amazon and now threatening the Tongass Forest in Alaska, and the ailing Everglades. He believes we can halt this slide into mass extinction, but we must start now. As we go to the polls in November, we should rate the candidates on how they would address this issue.

Mary :: 11:52 AM :: Comments (2) :: Digg It!