Something to Think About
The Current Mass Extinction:
Is the biosphere today on the verge of anything like the mass extinctions of the geological past? Could some equivalent of meteorite impacts or dramatic climate change be underway, as humankind's rapid destruction of natural habitats forces animals and plants out of existence?
Increasingly, researchers are doing the numbers, and saying, yes, if present trends continue, a mass extinction is very likely underway. The evidence is pieced together from details drawn from all over the world, but it adds up to a disturbing picture. This time, unlike the past, it's not a chance asteroid collision, nor a chain of climatic circumstances alone that's at fault. Instead, it is chiefly the activities of an ever-growing human population, in concert with long-term environmental change.
From:
http://www.pbs.org/wgbh/evolution/library/03/2/l_032_04.html
