The Sixth Extinction

  • 29/06/1994

IN THESE interdisciplinary times, biologists are equally at home with political theory. Garrett Hardin's essays, Life Boat Ethics and The Tragedy of the Commons constitute 2 of the major political manifestos of our time. James Lovelock's notion of Gaia or David Ehrenfeld's The Arrogance of Humanism question the anthropocentrism so endemic to political theory. The work of the Harvard biologist Edward Wilson stands midway. As one of the founding fathers of sociobiology, Wilson has faced flak; as the author of the poetic Biophilia, he has been lavishly praised.

The Diversity of Life is an epic elaboration on diversity and extinction. It begins in an Amazon teeming with secrets but darkened by the pall of destruction. The tropical rainforest is a "microcosm of scientific exploration (whose) unsolved mysteries...are formless and seductive".

As Wilson reflects on the origins and fate of diversity, inevitable questions about science begin to emerge. Science is not this mathematical model or that experiment. Unlike physics or chemistry, biology has many grey areas. "In fact evolution is so messy that a faithful description of real cases converts science into natural history in which unique details are as important as the principles by which they are explained."

Science's roots are more primordial, not unlike the rainforests. 150 million years old, these forests force us to look afresh at space and time. Consider the humble tree-trunk: "Here, space is not measured in Euclidean dimensions but fractally....In a fractal world, an entire ecosystem can exist in the plumage of a bird." Out of these hoary trees springs the question of life's diversity, which is then domesticated into the puzzle-solving of modern science.

Wilson argues that diversity provides the key to preserving the world as we know it. The crucible of life took a billion years to form; how much force does it take to break the flow of evolution? And how long does life take to restore itself? This dialectic of extinction and diversity propels the argument. Regarding extinctions, Wilson observes that nature itself performs experiments, as seen in the volcanic eruption at Krakatoa. All life was stamped out on the island, but one could also observe "the complete assembly of a geographical ecosystem from the very beginning".

History displays 5 major extinctions: the Ordovician (440 million years ago), Devonian (365), Permian (245), Triassic (210) and Jurassic (66). After each cataclysm, nature took a long time to recover. Hence the need to confront the 6th great extinction -- the human-made one: "We don't see the last butterfly of a species snatched from the air by a bird or the last orchid killed by the collapse of its supporting tree in some distant forest."

If evolution can occur rapidly, why should we worry about species extinction? "New species are usually... not fine tuned by episodes of natural selection. The richest ecosystems build slowly over a million years. Creation is part of deep history and the planet does not have the means nor the time to see it repeated." It is simply a question of "One earth, one experiment."

The metaphor that ties the book together is the idea of information. For Wilson, the forest is a great encyclopaedia, a nested series of worlds waiting to be catalogued. The only danger is that information transforms pulsating life into disembodied fact. A gene in a gene bank is not a stem of rice in a field. One is information; the other a way of life, superbly concrete, uniquely local. But the biology that Wilson advocates is uniquely open to this and even sensitive to local knowledges.

The author realises that farmers and tribals are scientists; in the goose-stepping march of biotech, the loss of their knowledge would be fatal. His search for diversity is a search for a new biology and a new ethic, an ethic that moves beyond anthropocentrism. "Men," he says, "are newcomers, dwelling among six legged masses." One wishes Wilson would explore the ethic for diversity in greater detail. Nevertheless the book is rich, to be read at several levels, like his beloved rainforests.

Shiv Viswanathan is associated with the Centre for the Study of Developing Societies

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