Valuing Common Species

+ See all authors and affiliations

Science  08 Jan 2010:
Vol. 327, Issue 5962, pp. 154-155
DOI: 10.1126/science.1182818

You are currently viewing the summary.

View Full Text


Aldo Leopold's dictum that “To keep every cog and wheel is the first precaution of intelligent tinkering” (1) has been oft repeated in the context of environmental management. The argument is beguilingly simple. In the absence of a detailed understanding of what each species does in an ecosystem, it would be foolish to allow the loss of any one of them. It is the precautionary principle writ large and, given its enormous ramifications for the ways in which people interact with the natural world, ecologists have spent much intellectual energy, time, and resources in determining whether it has a strong empirical basis (2). Indeed, some of the best-known recent ecological experiments have examined the consequences of varying the numbers of species in a small area on ecosystem function. This focus assumes that the importance of retaining Leopold's cogs and wheels lies mostly in the differences between them. However, a growing body of work on common species underlines that having sufficient copies of some key pieces may be equally, and perhaps often more, important.