"There are literally thousands of new species sitting in storage at museums," says Quentin Wheeler, a renowned taxonomist and founder of the International Institute for Species Exploration at Arizona State University. Identifying these species isn't just to satisfy curiosity; we need a clear understanding of species in order to best organize conservation efforts. Here's the snag: To verify a new species, a taxonomist must examine the type specimens—the preserved representative samples of every known plant and animal—of each similar existing species to document the differences. Some animals must be compared with hundreds of specimens, and those might be anywhere in the world. Many are too fragile to ship. But Wheeler thinks he has a solution that could dramatically speed up the classification and identification of species.
Every year, taxonomists introduce about 20,000 species. In the same period, an estimated 30,000 vanish. At that rate, the majority of Earth's inhabitants could disappear before they're known to science. Simply by making it easier to examine existing organisms, Wheeler says his project will help bump the species description rate to 200,000 a year—a clip that could make it possible to name the world's commonly estimated 20 million unknown species within 50 years.
Some scientists, however, think even e-types won't get the job done fast enough. Genetic testing, they argue, is the key. Leading this movement is Canadian evolutionary biologist Paul Hebert, who wants to assign every species a DNA "bar code" based on variations in a gene that nearly all organisms possess. A new species would be identified not by its physical divergence from existing type specimens but by the difference between its bar code and all the others. Because the system is fast and cheap—the technique requires basic laboratory skills and can process 95 samples in two hours for $10 apiece—Hebert says it could uncover every unknown plant and animal by 2025.
But bar-coding is fast and cheap because it uses just one piece of one gene—and that makes it prone to errors. In 2008, Pyle made a definitive distinction between two new fish species, even though their bar codes were essentially identical. "It's a blunt instrument," Wheeler says of the DNA system. "One gene just isn't sufficient." Looking at actual specimens is an art, he says. Plus, it's fun. Although he admits that someday it might be possible to define new species using only DNA, he doesn't like that idea much: "That would make taxonomy too boring to be worth doing."
Characterizing barcoding as a "blunt instrument" is a half truth - in many cases it has revealed cryptic species that were not recognized on the basis of morphology, which also turns out to be a "blunt instrument" when analyzing such groups. In light of these limitations, the obvious synergy that would emerge from a combined approach seems palpable. However, instead of stitching light images together using a 3-D model, it would seem that much more useful information could be obtained from a CT scan. Combine that with a DNA barcode and now you're on to something!
this is cool
All types of data have limits and at some point fail (i.e. are “blunt”). That's why we need many complimentary approaches. However, it is unfair to blame morphology for not recognizing “crypic species” when by definition morphologically cryptic species are morphologically cryptic. It is a specious argument often used by DNA barcode proponents. The barcode is 650 bases of one part of one gene in one organellar genome. The external morphology is information expressed from across the whole genome + the process of development. Which will ultimately be the crudest estimate of biodiversity is obvious. We need all kinds of data to understand the natural world DNA, morphology and more. That is why it is exciting!