Ecology is a broadly heterogenous discipline, with many theories and methods, encompassing a wide spectrum of fields, from population biology and community ecology, to ethology, biogeography and evolution. What, if anything, brings these diverse practices and ideas together? Odenbaugh examines the historical efforts of several population biologists -- Richard Levins, Richard Lewontin, Robert MacArthur, and E. O. Wilson, otherwise known as the "Marboro Circle" -- to craft a synthesis between "evolutionary play" and the "ecological theater" based on mathematical models and certain metaphysical commitments. Mittwollen offers a contemporary perspective, suggesting that evolutionary perspectives can help resolve the traditional dichotomy between reductionistic population ecology and the more holistic systems ecology.

Organized by: Anya Plutynski

Greg Cooper, Washington and Lee University
"Unification without Deductivism: Examples from Theoretical Ecology"

The unificationist approach to scientific explanation as developed, for example, by Friedman and Kitcher traces its roots back to Hempel's influential covering-law model. In particular, the more recent views share Hempel's emphasis on the deductive relationship between explanans and explanandum. At about the same time Friedman and Kitcher were developing their covering-law-inspired deductivist views, however, Hempel was in the process of giving up on deductivism. Why did Hempel bail on deductivism? What are the prospects for recognizing unification as an explanatory virtue in a world where deductivism fails? Using examples from theoretical ecology, this paper addresses these two questions.

Jay Odenbaugh, University of Calgary
"The "Marboro Circle", Theoretical Population Biology, and Unification"

In the mid-1960s, population biologists Richard Levins, Richard Lewontin, Robert MacArthur, and E. O. Wilson, otherwise known as the "Marboro Circle", met and discussed the future of population biology. Both molecular biology and ecosystem ecology were securing positions and funding at the expense of evolutionary biology and population/community ecology (Palladino 1993, Wilson 1994). These individuals proposed and argued for a unified theoretical population biology where the population and community are objects to be studied without first decomposing or incorporating them into other units. In this paper, I examine several issues. First, I explore why these biologists saw these "competing" programs of molecular biology and ecosystem ecology as problematic. I argue that Lewontin (1974) and Levins (1966, 1968) contain methodological critiques of these programs respectively and consider their arguments. Second, I consider how this new theoretical population biology would unify otherwise disparate parts of population biology such as evolutionary biology, population and community ecology, ethology, and biogeography. I suggest that their unificationist methodology consisted in (a) the use of certain types of mathematical models or model building strategies in areas which had not fully felt quantitative methods, (b) the attempt to connect the "evolutionary play" and "ecological theater" (Hutchinson 1965) through models which contained state variables and parameters from population genetics and ecology (Levins 1966, 1968. MacArthur 1962, 1965, MacArthur and Levins 1967, and MacArthur and Wilson 1967), and (c) metaphysical theses about the nature of evolutionary and ecological wholes and inappropriateness of certain forms of reductionism and holism. Third, I consider the relevance of recent work on unification by Morrison (2000) to the unificationist program of the Marboro Circle.

Arend Mittwollen, Universit”t Bremen
"Evolutionary Ecology - a Tool for Unification?"

In my paper I want to discuss the question of unity in ecology. Ecology mostly is considered a heterogenous discipline with lots of different theories and methods. Usually one distinguishes between two big camps. One is the reductionist population ecology that wants to explain big ecological entities out of the properties of their elements, the other one is systems ecology that consideres itself a holist discipline trying to understand functions of whole systems that are not reducible to their elements. Although there are other approaches to ecology than population ecology and systems ecology like community ecology, autecology, landscape ecology etc. most of these different ways of ecology can be subsumed either to the reductionist population ecology approach or to the holist systems ecology approach. Both ways of ecological research try to unify ecology by means of different explanations. The population ecology account wants to understand and unify ecological phenomena by means of reduction. They reduce properties of complex phenomena to the properties of simpler ones. The complexity of ecology can be understood out of the underlying individual elements and their processes. Population ecology tries to reduce complex ecological patterns to fundamental (mostly genetical) biological regularities. By this way many diverse ecological processes can be unified. Systems ecology on the other side tries to unify ecology by means of functional analogies. It is looking for mathematical equations being applicable to every ecological system. By this procedure it is asking for a structural unity of the ecological world using Çstructural laws' to describe ecological objects. I will demonstrate that a third big approach can be identified in ecology which I will call "evolutionary ecology". This approach has the possibility to combine systems ecology and population ecology approaches. It will suggest a way of unifying ecology which is more sucessful than the two just mentionend. Normally the field of evolutionary ecology is considered being a part of population ecological thinking but I will show that it is more than that and that it is justified to consider evolutionary ecology the third big approach in ecology. Evolutionary ecology wants to explain ecological phenomena by means of evolutionary mechanisms. Those mechanisms are mostly considered being genetical ones, therefore, one can say that evolutionary ecology is reductionist and is not too different from population ecology. But it brings in a new component: the historical account. Since evolutionary biology as a historical science has to handle with contingent processes and results of evolution the unification through evolutionary ecology can not be a unification through laws. Anyway, by means of evolutionary ecology ecologists are (somtetimes) able to understand why ecological phenomena are how they are by examining their evolution and historical genesis. Evolutionary Ecology can increase our understanding of nature with the help of more or less precise evolutionary mechanisms by reducing complex contemporary phenomena to simpler ones of the past. Therefore, evolutionary ecology has the ability to unify ecology by means of its historical account. It helps to understand complex ecological phenomena much better by showing that and how they evolved from ancient simpler phenomena. The increase of understanding lies in the explanatory unification that is reached by demonstrating contemporary complex phenomena as outcomes of former much simpler entities.