Sandra D. Mitchell

Dimensions of Scientific Law

Biological knowledge does not fit the image of science that philosophers have developed. Many argue that biology has no laws. Here I criticize standard normative accounts of law and defend an alternative, pragmatic approach. I argue that a multidimensional conceptual framework should replace the standard dichotomous law/accident distinction in order to display important differences in the kinds of causal structure found in nature and the corresponding scientific representations of those structures. To this end I explore the dimensions of stability, strength, and degree of abstraction that characterize the variety of scientific knowledge claims found in biology and other sciences.

Competing Units of Selection?: A Case of Symbiosis

The controversy regarding the unit of selection is fundamentally a dispute about what is the correct causal structure of the process of evolution by natural selection and its ontological commitments. By characterizing the process as consisting of two essential steps--interaction and transmission--a singular answer to the unit question becomes ambiguous. With such an account on hand, two recent defenses of competing units of selection are considered. Richard Dawkins maintains that the gene is the appropriate unit of selection and Robert Brandon, in response, argues that the individual organism is better suited to the role. This paper argues that by making explicit the underlying questions that each of these views addresses, the apparent conflict can be resolved. Furthermore, such a resolution allows for a more complete and realistic understanding of the process of evolution by natural selection.

Integration without Unification: An Argument for Pluralism in the Biological Sciences

In this article, we consider the tension between unification and pluralism in biological theory. We begin with a consideration of historical efforts to establish a unified understanding of evolution in the neo‐Darwinian synthesis. The fragmentation of the evolutionary synthesis by molecular evolution suggests the limitations of the general unificationist ideal for biology but not necessarily for integrating explanations. In the second half of this article, we defend a specific variety of pluralism that allows for the integration required for explanations of complex phenomena without unification on a large scale.

Ceteris Paribus — An Inadequate Representation For Biological Contingency

It has been claimed that ceteris paribus laws, rather than strict laws are the proper aim of the special sciences. This is so because the causal regularities found in these domains are exception-ridden, being contingent on the presence of the appropriate conditions and the absence of interfering factors. I argue that the ceteris paribus strategy obscures rather than illuminates the important similarities and differences between representations of causal regularities in the exact and inexact sciences. In particular, a detailed account of the types and degrees of contingency found in the domain of biology permits a more adequate understanding of the relations among the sciences.

Emergence: logical, functional and dynamical

Philosophical accounts of emergence have been explicated in terms of logical relationships between statements (derivation) or static properties (function and realization). Jaegwon Kim is a modern proponent. A property is emergent if it is not explainable by (or reducible to) the properties of lower level components. This approach, I will argue, is unable to make sense of the kinds of emergence that are widespread in scientific explanations of complex systems. The standard philosophical notion of emergence posits the wrong dichotomies, confuses compositional physicalism with explanatory physicalism, and is unable to represent the type of dynamic processes (self-organizing feedback) that both generate emergent properties and express downward causation.

Function, fitness and disposition

In this paper I discuss recent debates concerning etiological theories of functions. I defend an etiological theory against two criticisms, namely the ability to account for malfunction, and the problem of structural “doubles”. I then consider the arguments provided by Bigelow and Pargetter (1987) for a more “forward looking” account of functions as propensities or dispositions. I argue that their approach fails to address the explanatory problematic for which etiological theories were developed.

Exporting Causal Knowledge in Evolutionary and Developmental Biology

In this article I consider the challenges for exporting causal knowledge raised by complex biological systems. In particular, James Woodward’s interventionist approach to causality identified three types of stability in causal explanation: invariance, modularity, and insensitivity. I consider an example of robust degeneracy in genetic regulatory networks and knockout experimental practice to pose methodological and conceptual questions for our understanding of causal explanation in biology.

The Superorganism Metaphor: Then and Now

As John Maynard Smith1 has said: Our choice of models, and to some extent our choice of words to describe them is important because it affects how we think about the world … our choice of model decides what phenomena we regard as readily explicable, and which need further investigation, (p. 120.)

Multilevel Research Strategies and Biological Systems

Multilevel research strategies characterize contemporary molecular inquiry into biological systems. We outline conceptual, methodological, and explanatory dimensions of these multilevel strategies in microbial ecology, systems biology, protein research, and developmental biology. This review of emerging lines of inquiry in these fields suggests that multilevel research in molecular life sciences has significant implications for philosophical understandings of explanation, modeling, and representation.

After Fifty Years, Why Are Protein X-ray Crystallographers Still in Business?

It has long been held that the structure of a protein is determined solely by the interactions of the atoms in the sequence of amino acids of which it is composed, and thus the stable, biologically functional conformation should be predictable by ab initio or de novo methods. However, except for small proteins, ab initio predictions have not been successful. We explain why this is the case and argue that the relationship among the different methods, models, and representations of protein structure is one of integrative pluralism. Our defence appeals to specific features of the complexity of the functional protein structure and to the partial character of representation in general. We present examples of integrative strategies in protein science. 1. Introduction 2. Partiality of Representation 3. Protein Functional Complexity 4. Modelling Protein Structure 4.1 Integrating ab initio and experimental models 4.2 Integrating multiple experimental models 5. Conclusion 1. Introduction 2. Partiality of Representation 3. Protein Functional Complexity 4. Modelling Protein Structure 4.1 Integrating ab initio and experimental models 4.2 Integrating multiple experimental models 4.1 Integrating ab initio and experimental models 4.2 Integrating multiple experimental models 5. Conclusion