Dodgy gut? You must be grateful

Modern biology has taught us that life is everywhere engaged in a relentless and brutally competitive struggle for existence. We are told that only the fittest survive long enough to pass on their successful genetic endowment to the next generation, who then continue the never-ending struggle for supremacy in the game of life. The influence of this idea is all-pervasive. We see its imprint in almost every aspect of our modern world, but perhaps nowhere more forcefully than in economics, which has accorded competition a key role in its conceptual pantheon, with dire consequences for biodiversity and the diversity of human cultures.

But is it possible that biologists have underplayed, or even ignored, modes of interaction that might complement and ameliorate the competitive relationships that apparently exist in nature? In this well-written, accessible and delightful book, intended for a non-specialist audience, Tom Wakeford argues that life, for all its competition, trial and tribulation, could not exist without an underlying, all-encompassing emergent network of cooperative, symbiotic relations involving myriad and diverse beings.

Symbiosis is the "long-term, intimate association between different organisms, usually involving microbes", Wakeford says. Every living system depends on such alliances, and although mostly cooperative, symbiotic relations need not always be so. Microbes such as fungi that are involved in cooperative relationships with plants can turn pathogenic if the host experiences stress. So can otherwise beneficial bacteria in our guts, should the delicate health of our intestines be upset.

Indeed, one of the major tenets of the competitive paradigm is that bacteria are, for the most part, pathogenic killers, a view that Wakeford attributes to Louis Pasteur, who "single-handedly spawned the antibacterial age". A more balanced view is that bacteria are "the eternal innovators in the history of life", and that without their metabolic creativity, which we have inherited as the biochemical workings of our cells, we would not be here to be made ill occasionally by a tiny minority of their number.

Symbiosis research has made other stunning discoveries, many of which are clearly described in the book. One highlight is the discovery that nucleated cells, such as our own, came about long ago when various bacterial types merged into single composite beings. Another is the way in which fungal threads in the soil distribute nutrients among plants, sponsoring those in the shade with sugars made by those in the light. Yet another is that light-emitting bacteria in deep-sea creatures might have evolved luminescence in order to be eaten by their hosts, thereby providing themselves with safe havens, and their carriers with the means of illuminating prey.

Modern biology has, until recently, ignored and often ridiculed this field of research, despite its achievements in spearheading a more comprehensive biological understanding. The first world war and the fear of communism drove the symbiological movement underground in the western world. Seeking to understand the horrors of the war, the great biologists of the time such as H. G. Wells, J. B. S. Haldane and Julian Huxley felt impelled to interpret symbiosis as being "underlain with hostility", while capitalists decried any hint that mutual aid might be the key dynamic in the living world.

There is much to learn from this book about how we must live if we are to find our rightful place in nature. We desperately need to learn the art of cooperative networking of our microbial relatives and, like them, we must learn to blur the boundaries between ourselves and the wider world so that it once again becomes part of who we are.

Stephan Harding is ecologist in residence, Schumacher College, Dartington.