Jay Odenbaugh

Ecologists attempt to understand the diversity of life with mathematical models. Often, mathematical models contain simplifying idealizations designed to cope with the blooming, buzzing confusion of the natural world. This strategy frequently issues in models whose predictions are inaccurate. Critics of theoretical ecology argue that only predictively accurate models are successful and contribute to the applied work of conservation biologists. Hence, they think that much of the mathematical work of ecologists is poor science. Against this view, I argue that model building is successful even when models are predictively inaccurate for at least three reasons: models allow scientists to explore the possible behaviors of ecological systems; models give scientists simplified means by which they can investigate more complex systems by determining how the more complex system deviates from the simpler model; and models give scientists conceptual frameworks through which they can conduct experiments and fieldwork. Critics often mistake the purposes of model building, and once we recognize this, we can see their complaints are unjustified. Even though models in ecology are not always accurate in their assumptions and predictions, they still contribute to successful science.

Sahotra Sarkar’s Biodiversity and Environmental Philosophy is a welcome addition to the fields of environmental philosophy and the philosophy of science. First, his book has a rigorous and careful discussion of why we should preserve biodiversity. This is all the more important since much of environmental ethics has rested on normative claims which are unclear in meaning, appear unjustified at best and unjustifiable at worst, and are politically ineffective. Second, Sarkar is at home in the science of conservation biology and offers important analyses of methodological issues in both ecology and conservation biology. Third, his book does not sustain what might be thought of as a “North American bias” but takes seriously environmental issues and perspectives from many different places like Australia and India. In this commentary, I raise worries and open questions that can be divided into four sections: (a) those concerning moral philosophy, (b) those concerning ecology and in particular whether we are in an extinction crisis, (c) how biodiversity is defined as a concept, and (d) what the aim and structure of conservation biology is. Ultimately, though my analysis is critical at some junctures, its purpose is to repay and hopefully improve on Sarkar’s rewarding analysis. Let me now turn from praise to criticism

In 1974, John Maynard Smith wrote in his little book Models in Ecology, A theory of ecology must make statements about ecosystems as a whole, as well as about particular species at particular times, and it must make statements that are true for many species and not just for one… For the discovery of general ideas in ecology, therefore, different kinds of mathematical description, which may be called models, are called for. Whereas a good simulation should include as much detail as possible, a good model should include as little as possible. (1974.