IN "A Sand County Almanac" and his other writings, Aldo Leopold had many practical and visionary things to say about the interconnectedness of life on Earth. One of the most important was this:"The first rule of intelligent tinkering is to save all the parts."
This is the essential goal of the recently-announced National Biological Survey to be carried out over the next few years by the United States Department of the Interior. The idea is to consolidate biological research, which is now spread over eight federal bureaus, and to give it greater prominence. With more accurate and complete information, government land managers will be better able to foresee the protection-versus-development problems that loom over hundreds of millions of acres of public and private land.
It's hard to find a place in the United States where such problems do not play a prominent political role. Some, like the encroached-upon Florida Everglades or the dwindling salmon runs of the Pacific Northwest, are well known. Hundreds more are local but no less important to those affected, such as Benton Township in southwestern Michigan, where the endangered Mitchell's satyr butterfly held up construction of a bridge that could bring commerce to an area of high unemployment.
The sum of all the tinkering that's been done to North America over the past two centuries has been the loss - or potential loss - of many of the biological parts. There are now 760 domestic plant and animal species listed as threatened or endangered under the Endangered Species Act. The federal government, under court pressure, has agreed that another 450 species should be listed within the next four years.
Seen in a global context, such numbers are even more troubling. E. O. Wilson, a Harvard University scientist and eminent American expert on biodiversity, estimates that the current rate of extinction worldwide is many, many times the normal "background rate." It's comparable, he says, to five earlier "major extinction spasms" that took millions of years to get over.
In his recent book, "The Diversity of Life," Professor Wilson concludes that within the next 30 years "a 20 percent extinction in total global diversity . …