In this volume, the authors discuss what practical contributions ecology can and can't make in applied science and environmental problem solving. In the first section, they discuss conceptual problems that have often prevented the formulation and evaluation of powerful, precise, general theories, explain why island biogeography is still beset with controversy and examine the ways that science is value laden. In the second section, they describe how ecology can give us specific answers to practical environmental questions posed in individual case (...) studies, and argue for a new way to look at scientific error. A case study using the Florida panther is examined in the light of these findings. (shrink)

When is a law too idealized to be usefully applied to a specific situation? To answer this question, this essay considers a law in hydrogeology called Darcy''s Law, both as it is used in what is called the symmetric-cone model, and as it is used in equations to determine a well''s groundwater velocity and hydraulic conductivity. After discussing Darcy''s law and its applications, the essay concludes that this idealized law, as well as associated models and equations in hydrogeology, are not (...) realistic in the sense required by the D-N account. They exhibit what McMullin calls mathematical idealization, construct idealization, empirical-causal idealization, and subjunctive-causal idealization. Yet this lack of realism in hydrogeology is problematic for reasons unrelated to the status of the D-N account. These idealizations are also problematic in applied situations. Their problems require developing two supplemental criteria, necessary for their productive application. (shrink)

This paper discusses a deterministic model of the spread of an infectious disease in a closed population that was proposed byKermack &McKendrick . The mathematical assumptions on which the model is based are listed and criticized. The ‘threshold theorem’ according to which an epidemic develops if, and only if, the initial population density exceeds a certain value determined by the parameters of the model, is discussed. It is shown that the theorem is not true. A weaker result is stated and (...) proved.A new simplified version of the model is discussed. In this model it is assumed that an infected individual becomes infectious after a constant time and that it will removed after a constant time. Numerical simulations of this model show that the form of the fluctuations in the number of diseased individuals depends on the values of the parameters. The number of infectious individuals may oscillate up and down under certain circumstances. Necessary conditions for the number of infectious individuals to rise above previous levels are stated and proved. (shrink)

Thomas S. Kuhn's classic book is now available with a new index.

Recent controversy over the existence of biological laws raises questions about the cognitive aims of theoretical modeling in that science. If there are no laws for successful theoretical models to approximate, then what is it that successful theories do? One response is to regard theoretical models as tools. But this instrumental reading cannot accommodate the explanatory role that theories are supposed to play. Yet accommodating the explanatory function, as articulated by Brandon and Sober for example, seems to involve us once (...) again in a reliance on laws. The paper concludes that we must rethink both the nature of laws and theoretical explanation in biology. (shrink)

There is, at present, controversy surrounding the role of the mathematical models which typify the more theoretical portions of ecology and evolutionary biology. Within these sciences there has been controversy about the “testability” of these models, both in terms of the ability of the model to make precise enough claims about the world, and in terms of our ability to determine the values of theoretical parameters. There has been concern, particularly in ecology, about the lack of realism characteristic of most (...) models as well. These are, for the most part, issues involving the nature of theoretical explanation. Much of the current debate about null hypothesis testing, the unfalsifiability of theory, and the role of theory is symptomatic, it would seem, of the fact that these sciences have not settled on what to expect from their most mathematical theories. If there is one emerging theme, it is the need, again especially in ecology, for pluralistic theoretical treatments - which suggests that they may have been expecting too much. (shrink)

There is a long history of controversy in ecology over the role of competition in determining patterns of distribution and abundance, and over the significance of the mathematical modeling of competitive interactions. This paper examines the controversy. Three kinds of considerations have been involved at one time or another during the history of this debate. There has been dispute about the kinds of regularities ecologists can expect to find, about the significance of evolutionary considerations for ecological inquiry, and about the (...) empirical credentials of theoretical studies of competition. Each of these elements is examined with an eye toward gaining philosophical clarification of the issues involved. In the process, certain shortcomings of contemporary philosophical theories are revealed. In particular, I argue that plausibility arguments based on background considerations are an important part of the model building tradition, but that current accounts of the structure and evaluation of scientific theories do little to illuminate this side of theoretical ecology. (shrink)

There has been a significant amount of uncertainty and controversy over the prospects for general knowledge in ecology. Environmental decision makers have begun to despair of ecology's capacity to provide anything more than case by case guidance for the shaping of environmental policy. Ecologists themselves have become suspicious of the pursuit of the kind of genuine nomothetic knowledge that appears to be the hallmark of other scientific domains. Finally, philosophers of biology have contributed to this retreat from generality by suggesting (...) that there really are no laws in biology. This paper addresses these issues by providing a framework for thinking about general knowledge claims in ecology. It introduces a philosophical taxonomy that classifies generalizations into three broad categories – phenomenological, causal and theoretical. It then turns to the difficult problem of laws, arguing that, while there are probably no laws as that term has been understood in philosophy of science, it doesn't follow that everything in ecology is equally contingent. A mechanism for recognizing degrees of contingency in ecological generalizations is developed. The paper concludes by examining the implications of the analysis for the controversies noted at the outset. (shrink)

Ecology is an historical science in which theories can be as difficult to test as they are to devise. This volume, intended for ecologists and evolutionary biologists, reviews ecological theories, and how they are generated, evaluated, and categorized. Synthesizing a vast and sometimes labyrinthine literature, this book is a useful entry into the scientific philosophy of ecology and natural history. The need for integration of the contributions to theory made by different disciplines is a central theme of this book. The (...) authors demonstrate that only through such integration will advances in ecological theory be possible. Ecologists, evolutionary biologists, and other serious students of natural history will want this book. (shrink)

This book is a personal history and apology, written by one of this century's most distinguished small mammal ecologists, for a life in science spent working on problems for which no final dramatic conclusion was reached. Included along the way are some important anecdotes and history about Charles Elton and the pioneering work at the Bureau of Animal Population at Oxford University, from which most of modern population ecology has grown, and insigts on the philosophy and practice of science.

What is the role (or roles) of mathematical theory in ecology and evolutionary biology? How does the construction of such theory advance our understanding? The lack of clear answers to this pair of questions has been a source of controversy both within the sciences themselves, and in the philosophical discussions of these sciences as well. In an attempt to shed some light on these issues, I look at what some biologists have had to say on the matter and at some (...) particular examples. I then draw some morals about the constraints on a successful philosophical treatment of the problem and on the limitations of current philosophical approaches to this type of theoretical explanation. (shrink)