Elisabeth Lloyd

I argue that four of the fundamental claims of those calling themselves `genic pluralists'Philip Kitcher, Kim Sterelny, and Ken Watersare defective. First, they claim that once genic selectionism is recognized, the units of selection problems will be dissolved. Second, Sterelny and Kitcher claim that there are no targets of selection. Third, Sterelny, Kitcher, and Waters claim that they have a concept of genic causation that allows them to give independent genic causal accounts of all selection processes. I argue that each one of these claims is either false or misleading. Moreover, the challenge that arises from the availability of genic causal accounts, namely, the inability to choose on rational grounds among genic and higher-level accounts, is unsupported

I address the controversy in evolutionary biology concerning which levels of biological entity (units) can and do undergo natural selection. I refine a definition of the unit of selection, first presented by William Wimsatt, that is grounded in the structure of natural selection models. I examine Elliott Sober's objection to this structural definition, the "homogeneous populations" problem; I find that neither the proposed definition nor Sober's own causal account can solve the problem. Sober, in his solution using his causal view, imports precisely the information needed to make the structural definition effective. Finally, I indicate how the proposed definition can clarify which sorts of evidence could be brought to bear on the controversial case of the Myxoma virus.

Most models of generational succession in sexually reproducing populations necessarily move back and forth between genic and genotypic spaces. We show that transitions between and within these spaces are usually hidden by unstated assumptions about processes in these spaces. We also examine a widely endorsed claim regarding the mathematical equivalence of kin-, group-, individual-, and allelic-selection models made by Lee Dugatkin and Kern Reeve. We show that the claimed mathematical equivalence of the models does not hold. *Received January 2007; revised April 2008. †To contact the authors, please write to: Elisabeth Lloyd, Department of History and Philosophy of Science, 130 Goodbody Hall, Indiana University, Bloomington, IN 47405; e-mail: [email protected]; Richard Lewontin, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138; Marcus Feldman, Department of Biological Sciences, Stanford University, Stanford, CA 94305; e-mail: [email protected].

A precise formulation of the structure of modern evolutionary theory has proved elusive. In this paper, I introduce and develop a formal approach to the structure of population genetics, evolutionary theory's most developed sub-theory. Under the semantic approach, used as a framework in this paper, presenting a theory consists in presenting a related family of models. I offer general guidelines and examples for the classification of population genetics models; the defining features of the models are taken to be their state spaces, parameters, and laws. The suggestions regarding the various aspects of the characterization of population genetics models provide an outline for further detailed research

Climate change assessments rely upon scenarios of socioeconomic developments to conceptualize alternative outcomes for global greenhouse gas emissions. These are used in conjunction with climate models to make projections of future climate. Specifically, the estimations of greenhouse gas emissions based on socioeconomic scenarios constrain climate models in their outcomes of temperatures, precipitation, etc. Traditionally, the fundamental logic of the socioeconomic scenarios—that is, the logic that makes them plausible—is developed and prioritized using methods that are very subjective. This introduces a fundamental challenge for climate change assessment: The veracity of projections of future climate currently rests on subjective ground. We elaborate on these subjective aspects of scenarios in climate change research. We then consider an alternative method for developing scenarios, a systems dynamics approach called ‘Cross-Impact Balance’ (CIB) analysis. We discuss notions of ‘objective’ and ‘objectivity’ as criteria for distinguishing appropriate scenario methods for climate change research. We distinguish seven distinct meanings of ‘objective,’ and demonstrate that CIB analysis is more objective than traditional subjective approaches. However, we also consider criticisms concerning which of the seven meanings of ‘objective’ are appropriate for scenario work. Finally, we arrive at conclusions regarding which meanings of ‘objective’ and ‘objectivity’ are relevant for climate change research. Because scientific assessments uncover knowledge relevant to the responses of a real, independently existing climate system, this requires scenario methodologies employed in such studies to also uphold the seven meanings of ‘objective’ and ‘objectivity.’

I suggest following Paul Feyerabend's own advice, and interpreting Feyerabend's work in light of the principles laid out by John Stuart Mill. A review of Mill's essay, On Liberty, emphasizes the importance Mill placed on open and critical discussion for the vitality and progress of various aspects of human life, including the pursuit of scientific knowledge. Many of Feyerabend's more unusual stances, I suggest, are best interpreted as attempts to play certain roles--especially the role of "defender of unpopular minority opinion"--that are necessary to fulfilling Mill's conditions for rational exchange and optimal human development

Many of the commentators—let’s ignore their sex for the moment—suggested including women in the Feyerabend conference. Then the question was raised, “but are they of the right quality, status, rank?” That is, do they bring down the average quality of the conference in virtue of their being of inferior status, or, in Vincenzo Politi’s words, not “someone whose work is both relevant to the topic of the conference and also as widely recognized as the work of the invited speakers” (HOPOS-L archive, “CFP: Feyerabend Conference,” Tuesday, July 17, 2012, 14:57:20)? It is extremely important that such a discussion of quality, status, and rank recognize the scourge of evaluation bias and its long-term and pervasive consequences. One well-designed study this past year, published by the National Academy of Sciences, established prominent evaluation bias among both male and female science faculty in their evaluations of a student applying for a managerial job, who was randomly assigned either a male or a female name (Moss-Racusin et al. 2012). These professors examined the qualifications of the students and decided whether to hire them, what salary to give them, and whether to mentor themand howmuch to do so.The resultswere that both male and female scientists hired more men, gave them higher salaries, and offered more mentoring to them, even though themale applications were identical to the female applications. When probed about their reasons for not hiring or mentoring the female applicants, the professors explained that they based their decisions on the inferior competence of the applicant: the female applicants were perceived as less competent by all professors (with identical applications between males and females). This is what “evaluation bias” looks like, and it has been established in many, many contexts since the 1970s—this is only the most recent.

Two major clarifications have greatly abetted the understanding and fruitful expansion of the theory of natural selection in recent years: the acknowledgment that interactors, not replicators, constitute the causal unit of selection; and the recognition that interactors are Darwinian individuals, and that such individuals exist with potency at several levels of organization (genes, organisms, demes, and species in particular), thus engendering a rich hierarchical theory of selection in contrast with Darwin’s own emphasis on the organismic level. But a piece of the argument has been missing, and individuals at levels distinct from organisms have been denied potency (although granted existence within the undeniable logic of the theory), because they do not achieve individuality with the same devices used by organisms and therefore seem weak by comparison. We show here that different features define Darwinian individuality across scales of size and time. In particular, species-individuals may develop few emergent features as direct adaptations. The interactor approach works with emergent fitnesses, not with emergent features; and species, as a consequence of their different mechanism for achieving individuality (reproductive exclusivity among subparts, that is, among organisms), express many effects from other levels. Organisms, by contrast, suppress upwardly cascading effects, because the organismic style of individuality (by functional integration of subparts) does not permit much competition or differential reproduction of parts from within. Species do not suppress the operation of lower levels; such effects therefore become available as exaptations conferring emergent fitness—a primary source of the different strength that species achieve as effective Darwinian individuals in evolution.