I vividly remember watching an animated film about the immune system when I was in elementary school -- "Defense against Invasion." The cells of the immune system marched through the body, plucky, tireless, hard-hatted soldiers using all kinds of showy weapons destroy the invading evil microbes. The message was clear: We are at war with our germs; and few of us, child or adult, ever question this brand of clinical propaganda.

Our favorite metaphors for disease usually revolve around war. We talk of a "war on cancer" or a "war on the AIDS virus." We refer to our bodies being "invaded," and our cells being "attacked" or "taken over." The actions of our immune system are most often likened to a military campaign rallying to the body's defense.

Microorganisms, however, may not be mindless. In fact, their behavior suggests that they're quite intelligent, biologically speaking. In the September 1988 *Nature*, researcher John Cairns at the Harvard School of Public Health presented the results of three different experiments involving E. coli bacteria that suggested "bacteria can choose which mutations they should produce" in response to unfavorable environmental conditions. In one case they specifically changed two separate sets of genes in much less time than random mutation would permit. An astonished Cairns commented, "That such events ever occur seems almost unbelievable, but we have also to realize that what we are seeing probably gives us only a minimum estimate of the efficiency of the process.

Recent studies of certain staph strains in European clinics showed that the action of seven Separate genes were required to make the bacteria resistant to the antibiotic vancomycin and that these genes automatically switched on when vancomycin was introduced into the bacteria's environment. The eerie instant ability on the part of the bacteria to know exactly when the drug was introduced mystified the researchers, who could only speculate on the mechanism for this "clever" response. The details of the proposed "mechanism" are not so significant, but the apparent "cleverness" of the organisms is.

It seems microbes are fighting back. Infectious organisms are becoming multi-drug resistant more quickly than we can engineer new drugs. New diseases for which no effective remedies exist are evolving and infecting human hosts (see *The Coming Plague*, L. Garrett, Penguin, 1995). As long as we view these organisms, even entire classes of organisms, as our enemies, chances are slim that our relationship to them is going to improve. In fact, we've already seen in the cases of AIDS, Ebola, hepatitis, and hanta virus, and pneumonia, salmonella, E. coli, staph and strep infections -- not to mention the worldwide increase in resistant strains of malaria -- the roll on the human lives is going to continue and perhaps accelerate. Is there another approach, an alternative metaphor to war, which might serve us better -- cooperation, or co-evolution, for example?

- A World Supported By Microorganisms

It is important to remember that even if we could eradicate infectious organisms, this would be ecological and biological foolishness, Microorganisms are essential to the biosphere, much more so than we are; they are the oldest living creatures on the planet and they are found everywhere, from the frigid poles to boiling hot springs, from the tops of mountains to the ocean trenches. They form the base of the food chain for every other form of life. Microbiologist Lynn Margulis perceives higher organisms as more or less cooperative groupings of microorganisms: "From the paramecium to the human race, all life forms are meticulously organized, sophisticated aggregates of evolving microbial life,' she notes. "Far from leaving microorganisms behind on an evolutionary 'ladder,' we are both surrounded by them and composed of them" (Microcosmos with C. Sagan, Penguin, 1986).

We could not survive for long without the symbiotic microflorae that exist in our bodies. We can't digest our food without the microbes in our intestines, Other viruses and bacteria are prevalent throughout our bodies, quite possibly performing metabolic functions we are not aware of because we never search for or design experiments to obtain this kind of information. Mostly, medical researchers look for signs of harm; yet the fact is potentially lethal microorganisms live on us and inside us our entire lives without causing disease. The organism for spinal meningitis lives in our nasal passages and throats. Deadly strep and staph live on our skin at all times. The protozoan Pneumocystis carinii pneumonia exists in most people's bodies without causing any problems at all until someone becomes immuno-compromised. In *The Youngest Science* (Viking, 1983), Lewis Thomas speculated that one purpose of viruses might be to provide genetic exchange, acting as "a messenger service for carrying genetic information from one set of organisms to another.

Humans like to separate things into categories in order to better understand them, but nature doesn't recognize our artificial divisions. At this point, trying to separate infectious organisms from ones that are benign or even beneficial to us directly is biologically myopic and simple-minded. Virologists are now considering the idea that species of viruses don't really exist, that these organisms are changing so rapidly and so constantly that the best science can do is recognize "swarms" or "quasi-species" of viral strains that seem to move around together in time and space. We look at organisms in terms of their benefit or harm to ourselves, but the
greater genetic pool certainly doesn't regard life in this way. Life, on the
genetic and molecular level, is a huge, value-neutral pool of genes and biochemicals. Genes and their products are often grouped and organized in such a way that recognizable (to us) species result, but species are continually evolving, changing, dying off, and being created or recognized. Without this constant change and adaptation, life could not exist

- Essential Genetic Agents?

Infectious organisms may well contain genes within their genetic structure that are essential for the continued survival of all life on this planet. We are not yet sophisticated enough in our understanding of the biosphere and genosphere to know which combinations are expendable and which aren't. At this point, only Nature herself is wise and omniscient enough to know how the complex web of life is spun. From this perspective, with the rapidly evolving multiple resistance of infectious bacteria to antibiotics as evidence -- and the newly emerging diseases that have no cures -- it would seem that something in these microorganisms' genetics must be necessary for the balance and maintenance of all life (including human) on Earth. Perhaps the reason we can't at present eradicate all disease-causing organisms is because it is impossible. Eradicating them would quite possibly lead to eradicating ourselves.

Intriguing recent evidence from several studies indicates, in fact, that viruses may well provide us with genetic information we need to survive and evolve. In a paper published in the December 1996 Proceedings of the National Academy of Sciences, researchers describe experiments with human endogenous retroviruses, or HERVs. (Retroviruses are the same class of viruses to which HIV, the virus responsible for AIDS, belongs.) Retroviral genes inserted into the ancestral human genome more than 25 million years ago code for an important growth factor necessary for normal placental development. The researchers note, "An alteration of a gene expression pattern will only penetrate during phylogenesis if a better survival chance is associated." In other words, a selective advantage must be conferred for genes to become a highly conserved part of the species' genome as it evolves in the way that these genes have.

A second study in May 1996 in the same journal confirms these findings. According to researchers, "HERVs are very likely footprints of ancient germ-cell infections. HERV sequences encompass about one percent of the human genome." One of the characteristics of these retroviral insertions is their tendency to destabilize the genetic sequences around them. As these researchers point out, "Genomes are not static entities. In phylogeny, genomic changes are a precondition for selection and adaptation. While mutations are slow and therefore unsatisfactory tools for genomic modification, plasticity is more efficiently achieved by rearrangements driven by recombination and transposition." They comment further, "Ongoing evolution of retroelements, especially of their regulatory sequences, suggests that they are neither static genes nor selfish DNA. Instead, they may serve some cellular functions."

Still a third study (in *Virology*, 211, 1995) of HERVs and their role in human placental development concludes, "The evolutionary conservation and abundant expression of this endogenous retroviral protein in a specific cell type support the concept of a biological function." These genes are highly conserved, as indication of a clear and distinct selective advantage. They are expressed selectively in human tissues, which points to a specific function, and they are detected universally in all human tissues thus far examined, which indicates that they are necessary to the species' survival.

- Natural Cooperation

Scientific materialism perceives nature as mindless, savagely competitive, and uncaring; but a new (as well as ancient) view is emerging that all life and all matter are literally sentient -- and we are finally starting to appreciate cooperation as the powerful force it has always been. Researcher Lynn Margulis observes, again from *Microcosmos*: ". . . the view of evolution as chronic bloody competition among individuals and species, a popular distortion of Darwin's notion of 'survival of the fittest,' dissolves before a new view of continual cooperation, strong interaction, and mutual dependence among life forms. Life did not takeover the globe by combat, but by networking." Cooperation between molecules, genes, cells, and organisms is what makes life possible. We need to stop fighting and start cooperating.

So, perhaps, instead of talking in terms of "war," we should be asking how we can interact successfully with infectious microorganisms. We need to realize that it is no coincidence that most epidemics originate in conditions of overcrowding, overpopulation, poverty, war, and ecological devastation. Addressing social issues will undoubtedly prove to be as least as important as drug research, given the speed at which microbes are able to mutate and respond successfully to our arsenal of drugs. Furthermore, using metaphors of cooperation, medical practice would be grounded in a whole-systems approach to understanding and treating disease. In order for disease to develop, an entire range of protective and adaptive mechanisms has to fail to perform -- or, looking at it another way, for healing to occur an elaborate system of cooperation must be in place.