International Society for History, Philosophy, and Social Studies of Biology

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MONDAY, JULY 6  /  11:00 - 12:30  /  DS-M340
Individual papers
Genes, Individuals and Contingency

Can genes be Darwinian individuals?

Haixin Dang (University of Pittsburgh, United States)

In this paper, I will answer affirmatively the question posed in the title. Darwinian individuals ( DI ) are members of a Darwinian population ( DP ), which is a collection of things that has the capacity to undergo evolution by natural selection (Godfrey-Smith 2009, 6). Godfrey-Smith argues that genes cannot be DIs. DIs are bounded and countable objects and genes do not meet these criteria. I argue that under a molecular conception, the gene do in fact fulfill the criteria to be a DI. In doing so, I will be building from the molecular gene concept of Waters (1994) as well as recent research in molecular biology. I will show that genes, like macroscopic organisms, vary greatly in how Darwinian they behave. Not all genes are the same. Some genes, in fact, make paradigmatic DIs, while some fall in the middle, and some are indeed marginal. The Darwinian space, as introduced by Godfrey-Smith, can accommodate genes and can be used to understand the complex molecular world of the genome, while still maintaining that selection happens at other levels. The key argument I develop in this paper is that we should consider the more problematic cases of genes as analogous to collective entities that is, the gene can be conceived as one coherent object with discontinuous parts, like a colonial organism. Since the DI is dependent on a higher population concept, I will also argue that molecular genes can form a DP. I will also consider some possible objections and replies. In the final section of the paper, I will discuss the metaphysical aspect of the concept of individuals in biology. Many philosophers of biology privilege objects with natural boundaries as individuals that can be selected for. I argue that we ought to adapt our concept of individuality to accommodate molecular genes.

Gene regulatory models with evolutionary genetics models: Two cases

Steve Elliott (Arizona State University, United States)

Researchers have developed gene regulatory network (GRN) models partly to explain how major novelties arise within evolving lineages. Now biologists and philosophers debate about how those models will impact evolutionary theory. Some say that extant formal models of evolution can usefully accommodate GRN models. Others say that the GRN models are so different and powerful that they require us to drastically rethink how we model the causes of any variation within populations, and thus they require us to build a new formal structure for evolutionary mathematics. At the core of the debate is the status of formal models of evolutionary genetics, and as proponents of both sides have entrenched themselves, it’s doubtful that current argumentative strategies will settle anything. Often lost in the debate, however, is the actual work of recent biologists who work to incorporate GRN models with evolutionary genetic models. I present two case studies of recent research groups, one that uses simulated populations and the other that uses actual populations. The case studies show the epistemic aims of each research group, their integrated models, and the limits of their research. Given those results, I encourage the construction of similar studies, and I suggest how we might use those cases to help adjudicate the debate about the status of evolutionary genetics.

Biological individuality and the evolutionary contingency thesis

Alison McConwell (University of Calgary, Canada)

John Beatty (1995; 1982) cites the dynamic nature of evolution as responsible for the contingency of biological generalizations. Beatty’s Evolutionary Contingency Thesis (ECT) is originally discussed within the context of laws, but I wish to explore implications it may have for individuals relevant to natural selection. I will suggest that the impermanent character of evolution indicates a framework to think about individuals in biology, particularly evolutionary individuality. If biological laws and the mechanisms they govern are dependent on the outcomes of evolution, then it makes sense to ascribe contingency to mechanisms that underpin evolutionary individuality. In other words, if genetically-grounded mechanisms described and explained by biological laws are contingent and biological individuals emerge and are maintained by such mechanisms, then it follows that individuals are contingent too. Mutatis Mutandis for evolutionary individuality specifically. Examining evolutionary individuality through the lens of Beatty’s ECT may provide insight into the viability of pluralism and evolutionary individuals. For evolutionary individuality to be highly contingent, not only would individuals be subject to change over time, but the individual visible to selection could have been otherwise. This yields pluralism in the form of a temporal succession. It implies that a given definition of evolutionary individuality may no longer hold true at a later time. Thus, the coupling of pluralism with the notion of individuality may be supported by what one finds in nature, which suggests that a more open-ended view of individuality is required.