This is pretty cool. We're always being told how many species are being made extinct by our damn selfish human behavior. So it's nice to know there's another part of the story:
For centuries scientists have pondered a central question: How many species exist on Earth? Now, a group of researchers has offered an answer: 8.7 million.
Although the number is still an estimate, it represents the most rigorous mathematical analysis yet of what we know — and don't know — about life on land and in the sea. The authors of the paper, published Tuesday evening by the scientific journal PLoS Biology, suggest that 86 percent of all terrestrial species and 91 percent of all marine species have yet to be discovered, described and catalogued.
Hey, I bet if we try really, really hard, we can knock most of them off the planet before they even get discovered. In the article it is explained how the "estimate" was arrived at, but it sounds a SWAG to me.
