Efforts to conserve Earth's rich diversity of life have so far overlooked a vital component - the microorganism. That neglect could cost such efforts their success.
While some microbes are harmful, many are beneficial. Taken as a whole, microorganisms are essential for life on Earth. They provide the essential elements for every tree, and they help mammals, including humans, digest food. As Jennie Hunter-Cevera at the Lawrence Berkeley National Laboratory in California points out: ''With every plant and animal on this planet, there are microorganisms. If there weren't, the earth would look very much like Mars.''
Yet microorganism species - many of them still unknown to science - are disappearing as rapidly as are higher forms of plant and animal life. That deprives humanity of potentially important biological resources. Ultimately, it could threaten the foundation of higher forms of Earth's organic life.
Dr. Hunter-Cevera joined several other microbiologists to raise an alarm about this loss during the recent annual meeting of the American Association for the Advancement of Science (AAAS) in Baltimore.
There's more to microorganisms than bacteria and viruses. They include all life forms so small that we can only see them through microscopes. Growing knowledge of microbes has recently wrought a revolution in biology. Microbiologists now identify 20 major biological kingdoms among microbes. They also consider this an underestimate since they believe they have identified only a small percent of microbial species.
Some beneficial services of microbes are obvious: Yeast helps make bread. Molds and bacteria help make cheeses. The creaminess of chocolate comes from a yeast enzyme. Nitrogen-fixing bacteria enable legumes to make their own fertilizer. Oil-eating microbes help clean up oil spills.
Other microbial services are less noticeable and taken for granted. Microscopic marine algae and photosynthetic bacteria produce all of the oxygen in the sea and much of the oxygen in our air. Many animal species, including humans, couldn't digest their food without the help of microorganisms.
On a more fundamental level, evolutionary biologists now believe that all higher plants and animals evolved from microorganisms. Given microbes' biological importance, it is ironic that ''discussions ... and programs for biodiversity ... seem to have somehow missed out on microorganisms,'' says session organiser Sivramiah Shantharam of the US Department of Agriculture. In fact, ''there's no way that we have now to protect microbial species,'' says AAAS president Rita Colwell.
Some species used for industrial, medical, or research purposes are, in a sense, ''protected'' because those who use them maintain them. But the vast majority of microbes are literally out of sight and, therefore, out of mind. In fact, scientists can't even begin to plan how to protect microbes until they know what exactly there is to protect. What's needed now is an international program to identify as many microbial species as possible.
This need has been recognized in a number of declarations, including the United Nations Convention on Biological Diversity, which the United States has not signed. But little action has been taken. Now the International Council of Scientific Unions is organizing an effort to define programs that various nations could undertake to scout out microbes. This could be a useful beginning.
To be successful, technically advanced nations will have to help developing counties train the scientists and gain the facilities to carry out the research. That shouldn't be too expensive. Something like $100 million should get the programs rolling, according to Dr. Colwell. That's a small price for industrialized nations to pay to begin to understand what the world needs to do to preserve the foundation for organic life.