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.
Comments
Biologists make this sort of estimate pretty routinely. They usually point out that the overwhelming number of undescribed species are minor variations of various bugs and insects in remote jungles and rain forests, along with a few marine bottom-dwellers that are hard for us to observe. It's not like there are a bunch of interesting large mammals or food fish we haven't noticed. Of course, I agree with you that these estimates are based on little more than educated guesses. But I also think we ought to tread lightly where we can. I don't know what use passenger pigeons, dodos or Tasmanian wolves might be to us, but it still seems a shame that we killed them for no particular reason.
Yes, it's a SWAG, but that's not the problem. When you change the environment, existing species get eradicated, but according to Darwinian theory, new species are being formed all the time. Are we reducing biodiversity, or are we replacing an old biodiversity with a new one that's equally lush?
When we tore out the fence rows, we lost the ring-necked pheasant and gained the deer - but I'm more concerned about the fox grapes that used to grow in the fence row, and the fact that instead of 10,000 different species of wheat being raised, we're restricting ourselves to a few culivars of Roundup-Ready wheat. We are what we eat - and maybe the change in human nutrition is making us tastier piles of meat for whatever "bugs" come along to replace MRSA and AIDS - both of which appear to be new species.
Your assumption that new species are being created at the same rate that old ones are disappearing sounds a bit fishy to me. Wouldn't that be quite a coincidence? After all, humans have been overfishing the oceans and bulldozing the rain forests for only the last century or so.
Anyone willing to wade through some pretty daunting science and math can find an explanation of how the estimate was arrived at here:
Littlejohn, take a look at the land your house is sitting on. Does it look like a swamp?
Humans have been destroying habitat for millenia. We were salting the earth thousands of years ago.
And it's not a coincidence that new species get created when habitat changes, it's an article of faith among biologists. Life expands to fill the available habitat. Life includes random variations. Some variations are better able to take advantage of that new habitat, and they are the ones that survive.
You can hardly destroy habitat better than Mt. St. Helens did in 1980 when it blew its top - and yet 3 decades later it's teeming with life....