Roberta L. Millstein | University of California, Davis (original) (raw)

Papers by Roberta L. Millstein

Many philosophers have become familiar with Leopold's land ethic through the writings of J. Baird... more Many philosophers have become familiar with Leopold's land ethic through the writings of J. Baird Callicott, who claims that Leopold bases his land ethic on a 'pro-tosociobiological' argument that Darwin gives in the Descent of Man. On this view, which has become the canonical interpretation, Leopold's land ethic is based on extending our moral sentiments to ecosystems. I argue that the evidence weighs in favor of an alternative interpretation of Leopold; his reference to Darwin does not refer to the Descent, but rather to the Origin of Species, where Darwin discusses the interdependencies between organisms in the struggle for existence. It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. (Darwin, 1876, p. 430)

Studies in history and philosophy of biological and biomedical sciences, Jan 7, 2015

Philosophy of race has become a multi-faceted subfield of philosophy, drawing on philosophy of bi... more Philosophy of race has become a multi-faceted subfield of philosophy, drawing on philosophy of biology, metaphysics, philosophy of language, ethics, and political philosophy. Race cuts across disciplinary lines within philosophy. Moreover, disciplines outside philosophydincluding population genetics, anthropology, sociology, and educationdhave much to contribute to discourse about race. A persistent danger of interdisciplinary conversation is that of talking past each other. For instance, scholars in different disciplines have distinct race concepts and use local intellectual machinery to address questions about race. One simple way to address these issues is to have the relevant parties meet each other frequently and repeatedly. But there are some barriers to this strategy. It requires openness, patience, and charity from the participants, and physical proximity is an important consideration.

Reports of the National Center for Science Education, 2008

have endorsed views about random drift that, we will argue, rest on an implicit assumption that t... more have endorsed views about random drift that, we will argue, rest on an implicit assumption that the meaning of concepts such as drift can be understood through an examination of the mathematical models in which drift appears. They also seem to implicitly assume that ontological questions about the causality (or lack thereof) of terms appearing in the models can be gleaned from the models alone. We will question these general assumptions by showing how the same equation -the simple (p + q) 2 = p 2 + 2pq + q 2 -can be given radically different interpretations, one of which is a physical, causal process and one of which is not. This shows that mathematical models on their own yield neither interpretations nor ontological conclusions. Instead, we argue that these issues can only be resolved by considering the phenomena that the models were originally designed to represent and the phenomena to which the models are currently applied. When one does take those factors into account, starting with the motivation for Sewall Wright's and R.A. Fisher's early drift models and ending with contemporary applications, a very different picture of the concept of drift emerges. On this view, drift is a term for a set of physical processes, namely, indiscriminate sampling processes .

Biologists and philosophers have offered differing concepts of biological race. That is, they hav... more Biologists and philosophers have offered differing concepts of biological race. That is, they have offered different candidates for what a biological correlate of race might be; for example, races might be sub- species, clades, lineages, ecotypes, or genetic clusters. One thing that is striking about each of these proposals is that they all depend on a concept of population. Indeed, some authors have explicitly characterized races in terms of populations. However, including the concept of population into concepts of race raises three puzzles, all having to do with time. In this paper, I extend the causal interactionist population concept (CIPC) by introducing some simple assumptions about how to understand pop- ulations through time. These assumptions help to shed light on the three puzzles, and in the process show that if we want to understand races in terms of populations, we will need to revise our concept(s) of race.

We realized that our own geographic region—the San Francisco Bay Area—provided the necessary concentration of open, patient, and charitable scholars from many disciplines interested in race. During the 2013-2014 academic year, our group of biologists, philosophers, and social scientists met for two workshops (Stanford, UC Davis) and a public conference (UC Santa Cruz) to discuss a variety of concerns surrounding genomics and race. As a group we shared a commitment to thinking critically about how theoretical population genetics and genomics conceptualize and model certain constructs, such as “populations,” which, in turn, are deemed by some to be “races,” as theoretical achievements move from a circumscribed biological domain out to the general public

This year’s topic is “Genomics and Philosophy of Race.” Different researchers might work on distinct subsets of the six thematic clusters below, which are neither mutually exclusive nor collectively exhaustive: (1) Concepts of ‘Race’; (2) Mathematical Modeling of Human History and Population Structure; (3) Data and Technologies of Human Genomics; (4) Biological Reality of Race; (5) Racialized Selves in a Global Context; (6) Pragmatic Consequences of ‘Race Talk’ among Biologists.

I argue that the propensity interpretation of fitness, properly understood, not only solves the e... more I argue that the propensity interpretation of fitness, properly understood, not only solves the explanatory circularity problem and the mismatch problem, but can also withstand the Pandora’s box full of problems that have been thrown at it. Fitness is the propensity (i.e., probabilistic ability, based on heritable physical traits) for organisms or types of organisms to survive and reproduce in particular environments and in particular populations for a specified number of generations; if greater than one generation, “reproduction” includes descendants of descendants. Fitness values can be described in terms of distributions of propensities to produce varying number of offspring and can be modeled for any number of generations using computer simulations, thus providing both predictive power and a means for comparing the fitness of different phenotypes. Fitness is a causal concept, most notably at the population level, where fitness differences are causally responsible for differences in reproductive success. Relative fitness is ultimately what matters for natural selection.

The status of population genetics has become hotly debated among biologists and philosophers of b... more The status of population genetics has become hotly debated among biologists and philosophers of biology. Many seem to view population genetics as relatively unchanged since the Modern Synthesis and have argued that subjects such as development were left out of the Synthesis. Some have called for an extended evolutionary synthesis or for recognizing the insignificance of population genetics. Yet others such as Michael Lynch have defended population genetics, declaring "nothing in evolution makes sense except in the light of population genetics" (a twist on Dobzhansky's famous slogan that "nothing in biology makes sense except in the light of evolution"). Missing from this discussion is the use of population genetics to shed light on ecology and vice versa, beginning in the 1940s and continuing until the present day. I highlight some of that history through an overview of traditions such as ecological genetics and population biology, followed by a slightly more in-depth look at a contemporary study of the endangered California Tiger Salamander. I argue that population genetics is a powerful and useful tool that continues to be used and modified, even if it isn't required for all evolutionary explanations or doesn't incorporate all the causal factors of evolution.

In Darwin’s Sacred Cause, Adrian Desmond and James Moore contend that ‘‘Darwin would put his utmo... more In Darwin’s Sacred Cause, Adrian Desmond and James Moore contend that ‘‘Darwin would put his utmost into sexual selection because the subject intrigued him, no doubt, but also for a deeper reason: the theory vindicated his lifelong commitment to human brotherhood’’ (2009: p. 360). Without questioning Des- mond and Moore’s evidence, I will raise some puzzles for their view. I will show that attention to the structure of Darwin’s arguments in the Descent of Man shows that they are far from straightforward. As Desmond and Moore note, Darwin seems to have intended sexual selection in non-human animals to serve as evidence for sexual selection in humans. However, Darwin’s account of sexual selection in humans was different from the canonical cases that Darwin described at great length. If explaining the origin of human races was the main reason for introducing sexual selection, and if sexual selection was a key piece of Darwin’s anti-slavery arguments, then it is puzzling why Darwin would have spent so much time discussing cases that did not really support his argument for the origin of human races, and it is also puzzling that his argument for the origin of human races would be so (atypically) poor.

As a number of biologists and philosophers have emphasized, ‘chance’ has multiple meanings in evo... more As a number of biologists and philosophers have emphasized, ‘chance’ has multiple meanings in evolutionary biology. Seven have been identified. I will argue that there is a unified concept of chance underlying these seven, which I call the UCC (Unified Chance Concept). I will argue that each is characterized by which causes are consid- ered, ignored, or prohibited. Thus, chance in evolutionary biology can only be under- stood through understanding the causes at work. The UCC aids in comparing the different concepts and allows us to characterize our concepts of chance in probabilistic terms, i.e. provides a way to translate between ‘chance’ and ‘probability’.

Metascience

Roundtable review of Joan Roughgarden's _The Genial Gene: Deconstructing Darwinian Selfishness._

This paper aims to illustrate one of the primary goals of the philosophy of biology⎯namely, the e... more This paper aims to illustrate one of the primary goals of the philosophy of biology⎯namely, the examination of central concepts in biological theory and practice⎯through an analysis of the concepts of population and metapopulation in evolutionary biology and ecology. I will first provide a brief background for my analysis, followed by a characterization of my proposed concepts: the causal interactionist concepts of population and metapopulation. I will then illustrate how the concepts apply to six cases that differ in their population structure; this analysis will also serve to flesh out and defend the concepts a bit more. Finally, I will respond to some possible questions that my analysis may have raised and then conclude briefly.

Biological Theory, Jan 1, 2010

In “‘Population’ is Not a Natural Kind of Kinds,” Jacob Stegenga argues against the claim that th... more In “‘Population’ is Not a Natural Kind of Kinds,” Jacob Stegenga argues against the claim that the concept of “population” is a natural kind and in favor of conceptual pluralism, ostensibly in response to two papers of mine (Millstein 2009, 2010). Pluralism is often an attractive position in the philosophy of science. It certainly is a live possibility for the concept of population in ecology and evolutionary biology, and I welcome the opportunity to discuss the topic further. However, I argue that the case for conceptual pluralism has not yet been made. In what follows, I ﬁrst clarify the issues at stake before taking up the topic of conceptual pluralism and responding to Stegenga’s criticisms of the causal interactionist population concept.

Recently, much philosophical discussion has centered on the best way to characterize the concepts... more Recently, much philosophical discussion has centered on the best way to characterize the concepts of random drift and natural selection, and, in particular, whether selection and drift can be conceptually distinguished (Beatty, 1984; Brandon, 2005; Hodge, 1983, 1987; Millstein, 2002, 2005; Pfeifer, 2005; Shanahan, 1992; Stephens, 2004). These authors all contend, to a greater or lesser degree, that their concepts make sense of biological practice. So it should be instructive to see how the concepts of drift and selection were distinguished by the disputants in a high-profile debate; debates such as these often force biologists to take a more philosophical turn, discussing the concepts at issue in greater detail than usual. Moreover, it is important to consider a debate where the disputants are actually trying to apply the models of population genetics to natural populations; only then can their proper interpretations become fully apparent. (Indeed, I contend that some of the philosophical confusion has arisen because authors have considered only the models themselves, and not the phenomena that the models are attempting to represent). A prime candidate for just such a case study is what Provine (1986) has termed “The Great Snail Debate,” that is, the debates over the highly polymorphic land snails Cepaea nemoralis and C. hortensis in the 1950s and early 1960s. These studies represent one of the best, if not the best, of the early attempts to demonstrate drift in natural populations.

Philosophy

Recently, a number of philosophers of biology (e.g., Matthen and Ariew 2002; Walsh, Lewens, and A... more Recently, a number of philosophers of biology (e.g., Matthen and Ariew 2002; Walsh, Lewens, and Ariew 2002; Pigliucci and Kaplan 2006; Walsh 2007) have endorsed views about random drift that, we will argue, rest on an implicit assumption that the meaning of concepts such as drift can be understood through an examination of the mathematical models in which drift appears. They also seem to implicitly assume that ontological questions about the causality (or lack thereof) of terms appearing in the models can be gleaned from the models alone. We will question these general assumptions by showing how the same equation — the simple (p + q)2 = p2 + 2pq + q2 — can be given radically different interpretations, one of which is a physical, causal process and one of which is not. This shows that mathematical models on their own yield neither interpretations nor ontological conclusions. Instead, we argue that these issues can only be resolved by considering the phenomena that the models were originally designed to represent and the phenomena to which the models are currently applied. When one does take those factors into account, starting with the motivation for Sewall Wright’s and R.A. Fisher’s early drift models and ending with contemporary applications, a very different picture of the concept of drift emerges. On this view, drift is a term for a set of physical processes, namely, indiscriminate sampling processes (Beatty 1984; Hodge 1987; Millstein 2002, 2005).

Biological Theory, Jan 1, 2009

Biologists studying ecology and evolution use the term “population” in many different ways. Yet l... more Biologists studying ecology and evolution use the term “population” in many different ways. Yet little philosophical analysis of the concept has been done, either by biologists or philosophers, in contrast to the voluminous literature on the concept of “species.” This is in spite of the fact that “population” is arguably a far more central concept in ecological and evolutionary studies than “species” is. The fact that such a central concept has been employed in so many different ways is potentially problematic for the reason that inconsistent usages (especially when the usage has not been made explicit) might lead to false controversies in which disputants are simply talking past one another. However, the inconsistent usages are not the only, or even the most important reason to examine the concept. If any set of organisms is legitimately called a “population,” selection and drift processes become purely arbitrary, too. Moreover, key ecological variables, such as abundance and distribution, depend on a nonarbitrary way of identifying populations. I sketch the beginnings of a population concept, drawing inspiration from the Ghiselin-Hull individuality thesis, and show why some alternative approaches are nonstarters.

Journal of the History of Biology, Jan 1, 2008

Biologists and philosophers have been extremely pessimistic about the possibility of demonstratin... more Biologists and philosophers have been extremely pessimistic about the possibility of demonstrating random drift in nature, particularly when it comes to distinguishing random drift from natural selection. However, examination of a historical case-Maxime Lamotte's study of natural populations of the land snail, Cepaea nemoralis in the 1950s - shows that while some pessimism is warranted, it has been overstated. Indeed, by describing a unique signature for drift and showing that this signature obtained in the populations under study, Lamotte was able to make a good case for a significant role for drift. It may be difficult to disentangle the causes of drift and selection acting in a population, but it is not (always) impossible.

The neutral and nearly neutral theories of molecular evolution are sometimes characterized as the... more The neutral and nearly neutral theories of molecular evolution are sometimes characterized as theories about drift alone, where drift is described solely as an outcome, rather than a process. We argue, however, that both selection and drift, as causal processes, are integral parts of both theories. However, the nearly neutral theory explicitly recognizes alleles and/or molecular substitutions that, while engaging in weakly selected causal processes, exhibit outcomes thought to be characteristic of random drift. A narrow focus on outcomes obscures the significant role of weakly selected causal processes in the nearly neutral theory.

BioScience, Jan 1, 2008

We live in interesting times. Two well-known biologists — E. O. Wilson and Richard Dawkins — and ... more We live in interesting times. Two well-known biologists — E. O. Wilson and Richard Dawkins — and some of their well-known colleagues, who used to employ broadly similar selection models, now deeply disagree over the role of group selection in the evolution of eusociality (or so we argue). Yet they describe their models as interchangeable. As philosophers of biology, we wonder whether there is substantial (i.e., empirical) disagreement here at all, and, if there is, what is this disagreement about? We argue that a substantial disagreement over the processes that caused eusociality best explains this debate, yet the common practice of using overarching definitions for “group selection” and “kin selection” renders empirical differences difficult to detect. We suggest Michael J. Wade’s use of these terms as a basis for models that reveal different selection processes. Wade’s models predict different outcomes for different processes and thus can be tested.

Population genetics attempts to measure the influence of the causes of evolution, viz., mutation,... more Population genetics attempts to measure the influence of the causes of evolution, viz., mutation, migration, natural selection, and random genetic drift, by understanding the way those causes change the genetics of populations. But how does it accomplish this goal? After a short introduction, we begin in section (2) with a brief historical outline of the origins of population genetics. In section (3), we sketch the model theoretic structure of population genetics, providing the flavor of the ways in which population genetics theory might be understood as incorporating causes. In sections (4) and (5) we discuss two specific problems concerning the relationship between population genetics and evolutionary causes, viz., the problem of conceptually distinguishing natural selection from random genetic drift, and the problem of interpreting fitness. In section (6), we briefly discuss the methodology and key epistemological problems faced by population geneticists in uncovering the causes of evolution. Section (7) of the essay contains concluding remarks.

Studies in history and philosophy of biological and biomedical sciences, Jan 7, 2015

Reports of the National Center for Science Education, 2008

Metascience

Roundtable review of Joan Roughgarden's _The Genial Gene: Deconstructing Darwinian Selfishness._

Biological Theory, Jan 1, 2010

Philosophy

Biological Theory, Jan 1, 2009

Journal of the History of Biology, Jan 1, 2008

BioScience, Jan 1, 2008

This volume addresses fundamental issues in the philosophy of science in the context of two most ... more This volume addresses fundamental issues in the philosophy of science in the context of two most intriguing fields: biology and economics. Written by authorities and experts in the philosophy of biology and economics, Mechanism and Causality in Biology and Economics provides a structured study of the concepts of mechanism and causality in these disciplines and draws careful juxtapositions between philosophical apparatus and scientific practice. By exploring the issues that are most salient to the contemporary philosophies of biology and economics and by presenting comparative analyses, the book serves as a platform not only for gaining mutual understanding between scientists and philosophers of the life sciences and those of the social sciences, but also for sharing interdisciplinary research that combines both philosophical concepts in both fields.

The book begins by defining the concepts of mechanism and causality in biology and economics, respectively. The second and third parts investigate philosophical perspectives of various causal and mechanistic issues in scientific practice in the two fields. These two sections include chapters on causal issues in the theory of evolution; experiments and scientific discovery; representation of causal relations and mechanism by models in economics. The concluding section presents interdisciplinary studies of various topics concerning extrapolation of life sciences and social sciences, including chapters on the philosophical investigation of conjoining biological and economic analyses with, respectively, demography, medicine and sociology.

Charles Darwin's On the Origin of Species profoundly changed the way we view the natural world an... more Charles Darwin's On the Origin of Species profoundly changed the way we view the natural world and the way we view ourselves within that world. Ever since Darwin, we have seen species not as static entities specially created by a higher being, but as entities which change in response to environmental pressures. According to Darwin, such changes are primarily due to natural selection: the differential reproduction of organisms as a consequence of differences in fitness in a given environment. Thus, on Darwin's view, humans and other organisms are the result of a causal process that has taken place over millions of years, a causal process which has led to the adaptation of organisms within their environments.

Science, Jan 1, 2010

A review of _Biology’s First Law: The Tendency for Diversity and Complexity to Increase in Evolut... more A review of _Biology’s First Law: The Tendency for Diversity and Complexity to Increase in Evolutionary Systems_, by Daniel W. McShea and Robert N. Brandon. This review argues that the supposed "Zero-Force Evolutionary Law" (ZFEL) is neither a law nor zero-force.

random drift is an indiscriminate sampling process, meaning that it is a process where heritable ... more random drift is an indiscriminate sampling process, meaning that it is a process where heritable physical differences between entities (e.g., organisms, gametes) are causally irrelevant to differences in reproductive success. natural selection is a discriminate sampling process, meaning that it is a process where heritable physical differences between entities are causally relevant to differences in reproductive success.