How Taxonomy Helps Us Make Sense Out of the Natural World

For centuries, philosophers, naturalists and scientists have been trying to devise systems that group living things according to their similarities and presumed relationships. That's taxonomy the study of scientific classification. Charles Darwin's ideas about evolution had a profound effect on religion and science, but it was not until the 1960s that evolutionary classification came into its own. The system that eventually emerged, cladistics, combines biology and computer-assisted numerical analysis to gain insights into how plants and animals evolved.

One of the world's preeminent centers of taxonomy is the Smithsonian's National Museum of Natural History in Washington, D.C. There, scientists like spider expert Jonathan Coddington use cladistics to study an entomological collection that contains more than 31 million specimens. Each year some 9,000 scientists from all over the world visit the museum to work with its collection, and last year more than 140,000 specimens were sent out on loan.

Good taxonomy, Coddington says, can save money and lives; bad taxonomy can be costly. The gypsy moth that is now ravaging forests throughout the Eastern United States was brought here from Europe in the 19th century because of a case of mistaken identity. But it is science, not economics, that concerns taxonomists most. Coddington and many of his colleagues believe they are engaged in a race against time to identify and classify previously undiscovered species all over the world before they are wiped out by development.