Man’s heavy footprint threatens Nature’s diversity

We take so many things for granted that it’s hard to imagine life otherwise. In fact, we’d be paralyzed, rather like a bird worrying about whether it could fly.

This doesn’t mean we’re always right in our assumptions. If I took the potential absence of gravity as a given, for instance, it’d be a major error, right?

But let’s say that disappearing gravity is indeed my belief, and you happen to come by my home one day and I answer the door while tethered to a ball and chain designed to hold me down, just in case. I guess you might suggest that I really, really need to get some help.

Or maybe just some better knowledge. Bertrand Russell evidently had it right when he said, “Many people would sooner die than think; in fact, they do so.”

Now, if my delusion was purely personal, no great harm. But imagine tens of millions of people taking something equally nonsensical as true, with said belief guiding, in part, nontrivial matters such as who they vote for, how they raise their kids, even their entire stance vis-a-vis the world as a whole.

Now that might matter.

I just re-read biologist Edward O. Wilson’s 1992 opus, “The Diversity of Life,” which I’ve consulted now and then for about 15 years. Wilson is the world’s leading authority on ants, but to say that this is the iceberg’s tip of his erudition is like mentioning that they should have had a few more lifeboats on the Titanic.

A major thesis of the book is that we’re now in the “6th Great Extinction,” this one caused by us. His estimate at the time was that 20 percent or more of all plant and animal species will either be extinct by 2020, or doomed to early extinction, unless we changed course.

But instead, it’s gotten worse: the number of global “hot spots” – ecosystems at great risk – went from 18 in 1992 to 25 a decade later: “Hence, the foregoing estimates of extinctions based upon habitat reduction are, sadly, minimal and modest.”

Let’s consider Wilson’s now-dated 1992 estimate of about a billion billion insects alive around the planet, comprising a biomass of around a trillion kilograms. That’s a lot – but not much more than the weight of all humanity, and we’ve continued to breed like bunnies since then.

The idea that our single species weighs about the same as all the millions of insect species is staggering, and points to the degree to which we have dominated the available viable habitat of Earth.

And what of the earlier major extinctions? Wilson wrote that it required tens of millions of years to recover from each: “These figures should give pause to anyone who believes that what Homo sapiens destroys, Nature will redeem.”

This brings me back to nonsensical beliefs. Excuse my broad strokes, which nonetheless reflect polling numbers that have remained pretty stable, over the past couple of decades.

Roughly half of the folks in the good old U.S. of A. are Young Earth Creationists and believe that everything on the planet came along within the last 10,000 years. That is, they deny evolution, with all the consequences inherent in that belief.

Not incidentally, the more educated one is, the more likely one’s belief in evolution; only about 5 percent of scientists are Creationists.

In May 2007, three out of 10 Republican presidential candidates – let’s call ’em out, Tom Tancredo, Sam Brownback and Mike Huckabee – denied a belief in evolution. Imagine one of them as president.

Now, that might matter.

I’ll paraphrase (from his 1992 book) the question that Wilson said he is most frequently asked: If biodiversity is reduced enough, will the consequent collapse of ecosystems result in most species’ extinction?

“The only answer anyone can give is: possibly,” he wrote. “By the time we find out, however, it might be too late. One planet, one experiment.”

The shame is not that we might not be evolutionarily fit for our survival in even the short run, let alone our million years (about the average species life), but that we will truncate so many more viable evolutionary tracks, and that tens of millions of years will likely pass before diversity returns (if it does) to current levels.

And perhaps no fully self-aware, self-conscious critter will exist in that world. In that case, we will have wasted our opportunity to glorify the world in all its diversity with our unique gaze upon it.