Tools and All Species

Article excerpt

As time goes by, we scrutinize smaller and smaller parts of our bodies, and smaller and smaller niches of the planet. Nothing escapes our insatiable curiosity. Once we only knew river fish, caught with bare hands; then spears, and dip and seine nets; now deep-sea fishing fleet boats and floats, radar and gill nets. Fish biologists descend in bathyspheres and submarines to the deepest oceanic canyon, and trawlers scrape up odd saltwater nematodes and mollusks from the bottom sediments. We live in an era when no part of the biosphere remains uninfluenced by the human saga of discovery and exploration. And the story hinges on new tools.

Tools are additive in natural history. They rarely replace one another. Insect lovers, for instance, also began bare-handed. Then they added the butterfly net, and the aspirator for tiny insects that might slip through the net. Then traps such as ultraviolet lights, zappers, and sticky-paper to find new kinds of insects. Now foggers with insecticide to see who lives in the forest canopy on the farthest inaccessible twigs. But quick hands and eyes still count.

Equipment has improved the "eyesight" of natural history buffs by ten orders of magnitude, hastening new species discoveries, forcing new vocabularies and descriptions: microscopic metazoans, single-cell procaryotes, viruses; and, in taxonomy, bodyscape parts invisible to the unaided eye: chromosomes, organelles, stomata, nuclei. After light microscopes came scanning and transmission electron microscopes and microvideo. Dead dirt became living soil; pure water became living water. "An" insect became a bodyscape with mites in its spiracles and a metropolis of unicellular life-forms inhabitating its gut.

The latest surges come from three techno-innovations: electronic and digital technology; satellite transmitters (see GPS); and molecular biology.

I'm a conservative outdoorsman and didn't quite catch on to the digital and molecular influences until the mid-1980s. In the midst of an acrimonious controversy about the endangered population of the Mt. Graham red squirrel, the University of Arizona (which desired to cut many of the squirrel's trees to make room for new telescopes) questioned the taxonomic status of the squirrel. Was it really different from other related populations? And if not, could it be taken off the endangered species list? We all picked up run-over squirrels, and squirrels stored in refrigerators, and sent them to a lab to be sorted by allozymes (essentially enzyme proteins). We field biologists, now with a great affection for this six ounces of scampering rodent, shivered a bit in anticipation. Analyzers mixed squirrel proteins into a gel. They watched embedded proteins migrate at different speeds depending on their weight and charge (see electrophroesis illustration, left). They compared the patterns formed by protein migrations. The molecular "fingerprint" would show the similarities or differences. The Mt. Graham red squirrel was demonstrated to be the most different population of all the squirrels tested, and the University dropped the argument.

Allozyme electrophoresis, as the process is called, is now the "ancient technique" of molecular biology. In the 1990s, a group of proteinaceous acronyms for new techniques--PCR, RFLPs, RAPDs and DNA/RNA sequencing (see box, page 41)--were added. …