On Saturday night, the Explorer's Club held its annual dinner at the elegant Waldorf Astoria Hotel in Manhattan. A distinguished organization founded in 1904, the Club has been a meeting-place and resource for some of the most intrepid Americans in history. The first individuals to reach the North and South Poles, climb to the top of Mount Everest, probe the deepest point in the ocean, and land on the surface of the moon were all members of the Explorer's Club.

At this year's event, 1,000 current members, in costumes ranging from black tie to beaded buckskin, were there to celebrate the joys of exploration and pay tribute to the winners of the Club's honors. The hors d'oeuvres provided ample opportunity for culinary exploration. Alligator was served--roasted for the bold and as a Cajun stew for the less adventurous. Scorpion canapés, cricket pate, and a variety of sandwiches and sweets topped with toasted worms and garnished with fried larvae were crunchy delights. I missed the baked tarantula but did sample the stuffed eyeballs. While we dined, musicians played original compositions and brilliant lights swarmed the ceiling. Jim Fowler, a longtime member of the Explorer's Club, was there with his customary menagerie of exotic animals, including four rare species of owl, a hyperactive kangaroo, an acrobatic two-toed sloth, and a variety of engaging New World monkeys.

The festive mood framed serious discussions on exploration and the environment. This year's theme was The Balancing Act: Exploring Biodiversity, and E. O. Wilson, the recipient of the Explorer's Medal, delivered the keynote address. Wilson, a noted Harvard professor and Pulitzer Prize winner, spoke of his boyhood respect for Carl Linnaeus and other great explorers of the natural world. He recounted his early travels upon untrodden soil deep in the mountains of Sarawak and Borneo. He reminded us that the exploration of this planet's surface geography is coming to an end--that by the end of this century, every centimeter on the land would be mapped and known. The future of exploration, he insisted, lies in the living world all around us and beneath our feet.

He began with the terrestrial. New mammals, birds, and reptiles remain to be discovered. He argued that about half of all living species would be driven to extinction within this century by the destruction of their natural habitats by the hand of man--either directly or through climatic changes driven by global warming. Many species, he warned, could be lost forever before we have a chance to know them.

He continued with the small, describing the most prevalent animal species on the planet: the humble nematode, a tiny soil roundworm. Nematodes play a critical role in soil biology, providing the rich earth that sustains plant and animal life, and there may be more than one million different species of them. "So abundant are these humble worms," Dr. Wilson said, "that if the soil were stripped away, earth, as seen from space, would be blanketed by a haze of roundworms."

He concluded with the microscopic. We humans might be accurately described as nine parts bacteria to one part animal--we comprise a trillion different cells but are home to more than ten trillion bacteria. There is more bacterial diversity in one person's oral cavity or shoe than there is among plants and animals in a tropical rainforest. And yet, we know so little about these organisms. As for the fungi that live about us, only a few of what are sure to be hundreds of thousands of species are known.

Finally, Dr. Wilson led us to the greatest unknown: the world living deep beneath our feet. We now know that our biosphere extends at least 2 1/2 miles below the surface of the earth. Photosynthesis--light captured by bacteria, algae and plants--fuels life at the earth's surface, but high-energy chemicals, forged in the crucible of the deep, are converted to usable energy by subterranean bacteria. Taken together, these tiny creatures weigh many times more than all the biomass on the surface of the earth. As Dr. Wilson mused, "Should surface life be destroyed one day by an act of man or nature, these organisms would rise to the surface, evolve, and once again produce a rich diversity of plant and animal life."

Knowledge of our microbial companions immediate practical value as well: by understanding the inner workings of these organisms, we can harness the power of their transformative chemistry. I have firsthand experience with this particular field of exploration. During the 1990s, I helped to create a new biotechnology company, then called Diversa, to tap the power of microorganisms for new chemicals and fuels. Today, the study of soil bacteria and fungi are at the forefront of our efforts to create renewable biofuels. And the tools for discovery have evolved tremendously over the past several years. Thanks to rapid advances in technology--driven by our desire to understand ourselves--it is now possible to decipher DNA rapidly. The entire DNA text, or genome, of a plant or animal can be determined in a matter of weeks, a fungus in days, and a bacterium in mere hours. And the efficiency of our instruments is increasing.

Thanks to such advances, Dr. Wilson has been able to launch a comprehensive encyclopedia of life, one that describes not only the physical descriptions and habitats of all species on earth but their genomes as well. This bio-encyclopedia, already online in its early stages at www.eol.org, will function much like Wikipedia, drawing on many sources for photos of animals, descriptions of habitats, research data on behavior, biochemical analysis, and DNA sequence data. The fruition of this great project will take many generations, but it may hold the key to the continuation of life on earth. It is a great and worthy field for future explorers.