The Balance of Nature: Ecology's Enduring Myth

The Balance of Nature: Ecology's Enduring Myth

Language: English

Pages: 256

ISBN: 0691138982

Format: PDF / Kindle (mobi) / ePub


The idea of a balance of nature has been a dominant part of Western philosophy since before Aristotle, and it persists in the public imagination and even among some ecologists today. In this lively and thought-provoking book, John Kricher demonstrates that nature in fact is not in balance, nor has it ever been at any stage in Earth's history. He explains how and why this notion of a natural world in balance has endured for so long, and he shows why, in these times of extraordinary human influence on the planet's ecosystems, it is critical that we accept and understand that evolution is a fact of life, and that ecology is far more dynamic than we ever imagined.

The Balance of Nature traces the fascinating history of the science of ecology and evolutionary biology, from the discipline's early innovators to the advent of Darwin and evolution, to the brilliant and inquisitive scientific minds of today. Blending insights and entertaining stories from his own remarkable life in science, Kricher reveals how evolution is a powerful engine that drives ecological change, how nature is constantly in flux and, in effect, quite naturally out of balance--and how notions to the contrary are misguided and ultimately hazardous to us all.

The Balance of Nature forcefully argues that an understanding of the dynamic nature of ecology and evolution is essential to formulating policies of environmental ethics to guide humanity toward a more responsible stewardship of our planet's ecosystems.

 

 

 

 

 

 

 

 

 

 

higher than dogs but dogs were higher than lizards. Plants, with merely a “nutritive soul,” were near the bottom.15 No creature can ever change position on the great chain. To do so would violate its essence and imply that its purpose had been altered. Such alterations would be too profound to find acceptance in Aristotle’s scheme for the perfection, balance, and design by which nature is organized. Some interpreters of Aristotelian biology have suggested that the great chain hints of evolution

the first appearance of life on the planet. Life’s history is thus visualized as a dense genetic bush of variously related forms (a pattern commonly called “the tree of life”). Life forms change, evolve with time, many become extinct, but each shares a historical genetic connection with all others. Extinction represents dead stalk tips on the bush. Speciation represents newly branching stalks. Darwin used the metaphor of a many-branched bush to illustrate this concept, which he repeatedly called

about forty feet long and weighing up to seven tons, was only three steps from the Sun. And if ever an animal was at the apex of a food chain, it was Tyrannosaurus rex. Ecologists also recognize that other factors contribute to food chain length, including overall energy availability, dispersal and migration, and disturbance frequency. But lording over all other factors are the realities imposed by the laws of thermodynamics. Ecosystem studies blossomed in the 1950s and 1960s, in part as a result

winter litter, something they rarely do in nonmast years. Ecologists call this a “numerical response,” when a species’ population increases as its food becomes more abundant. But the mice do not confine their nibbling to just acorns. They have quite a good appetite for gypsy moth pupae. The more mice there are, the more pupae they eat. Thus the mice, who could be thought of as destroyers of oak seeds, may ultimately benefit the oaks in that they help alleviate the threat of defoliation from a

species would always exceed that of any one of the species when grown alone. Overyielding was tested in caddisfly species.20 Caddisflies are insects (Trichoptera, Hydropsychidae) with aquatic larvae. The larvae are suspension feeders, building a silklike net in a streambed that acts to filter particulate matter that is then devoured by the larvae. Three species of caddisfly, Hydropsyche depravata, Cerato- F o r t h e L o v e of B i o d i v e r s i t y 181 psyche bronta, and

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