Earth Equity News

Humans Driving Extinction Faster than Species Can Evolve. By Juliet Jowit, Guardian, March 7, 2010. "For the first time since the dinosaurs disappeared, humans are driving animals and plants to extinction faster than new species can evolve, one of the world's experts on biodiversity has warned. Conservation experts have already signaled that the world is in the grip of the 'sixth great extinction' of species, driven by the destruction of natural habitats, hunting, the spread of alien predators and disease, and climate change. However until recently it has been hoped that the rate at which new species were evolving could keep pace with the loss of diversity of life. Speaking in advance of two reports next week on the state of wildlife in Britain and Europe, Simon Stuart, chair of the Species Survival Commission for the International Union for the Conservation of Nature -- the body which officially declares species threatened and extinct -- said that point had now 'almost certainly' been crossed… The IUCN created shock waves with its major assessmentof the word's biodiversity in2004, which calculated that the rate of extinction had reached 100-1,000 times that suggested by the fossil records before humans… Extinction is part of the constant evolution of life, and only 2-4% of the species that have ever lived on Earth are thought to be alive today. However fossil records suggest that for most of the planet's 3.5bn year history the steady rate of loss of species is thought to be about one in every million species each year."

"Only 869 extinctions have been formally recorded since 1500, however, because scientists have only 'described' nearly 2m of an estimated 5-30m species around the world, and only assessed the conservation status of 3% of those, the global rate of extinction is extrapolated from the rate of loss among species which are known. In this way the IUCN calculated in 2004 that the rate of loss had risen to 100-1,000 per millions species annually -- a situation comparable to the five previous 'mass extinctions' -- the last of which was when the dinosaurs were wiped out about 65m years ago…Professor Norman MacLeod, keeper of paleontology at the Natural History Museum in London, cautioned… 'If things aren't falling dead at your feet that doesn't mean you're not in the middle of a big extinction event,' he said. 'By the same token if the extinctions are and remain relatively modest then the changes, [even] aggregated over many years, are still going to end up a relatively modest extinction event.'"