March 2019 Lunchtime Abstracts & Details

Should We Take Alternative Genetic Codes Seriously?
Janella Baxter, Center Postdoctoral Fellow
University Minnesota
Friday, March 1, 2019
12:05 pm
1117 Cathedral of Learning

Abstract: Our understanding of the genetic code – the precise assignment between nucleic acid triplets and amino acids – has always been characterized by an internal tension. Shortly after “decoding” the genetic code biologists discovered that some mitochondria and chloroplast genomes have diverse nucleic acid triplet-amino acid assignments. Nevertheless, biologists widely dismiss this diversity as being unrepresentative of the majority of life. The received approach has been to presuppose that the standard genetic code is relatively universal. That is from bacterium to elephant, the assignment between nucleic acid triplet and amino acid is the same. In this talk, I wish to argue that recent developments in both the genome sequencing of wild populations and development of synthetic genetic codes add to this tension. The sequencing of microbial genomes in the wild has revealed that alternative assignments between some nucleic acid triplets and natural amino acids have not only evolved from the standard assignment, but that these assignments are much more common than had previously been thought (Ivanova et al. 2014). The ubiquity of alternative genetic codes in microbial populations puts tension on two distinct hypotheses about the origin and evolution of the genetic code. One hypothesis is that a single genetic code emerged as a consequence of competition between communal organisms (Vetsigian et al. 2006). The prevalence of diverse genetic codes in communal organisms, however, shows that multiple genetic codes can be sustained in some environments. Another hypothesis is that once the standard genetic code was established, selection pressures “froze” it in place (Sella et al. 2006). Yet, discovery of alternative codes adds further evidence that the standard genetic code is not “frozen,” but allows for some degree of evolvability. Finally, I wish to highlight some ways synthetic genetic codes might enable the testing of some hypotheses about the origin and evolution of the standard genetic code. Synthetic genetic codes have recently been treated merely as evidence of how unlikely alternative genetic codes are to evolve in nature (Koonin 2017). Yet, some of the methods employed by synthetic biologists to expand the genetic code might be treated as analogous to what has happened in wild microbial populations. Furthermore, this technology might be useful for studying how robust life can be with an expanded genetic code. In the end, biologists should take alternative genetic codes into account.

Engaged Philosophy of Science - And Beyond
Kelli Barr
University of N. Texas
Tuesday, March 5, 2019
12:05 pm, 1117 Cathedral of Learning

Abstract: Scientists in the US increasingly are asked to account for the societal impact of their research. Science funders, elected officials, and members of the general public are asking serious questions about the public value of science. At the same time, universities in the US, especially public ones, seem to grow less hospitable to the pursuit of humanistic inquiry for its own sake. These developments suggest a shift both in the societal expectations of science and in the future prospects for academic philosophy. In response, some philosophers of science have proposed models for engaging with non-academic audiences interested in the public role of science. This presentation offers a characterization and analysis of the practical, conceptual, and normative challenges of such a task – how engaged philosophic work can be done, and what it looks like to do it well. After surveying existing models of “engaged philosophy,” I present a taxonomy of typical challenges to doing such work, chief among which are those rooted in disciplinary norms and practices that developed over the course of the 20th century. I then explore what lessons we can learn from two sources of experience grappling with these questions: (1) scientists seeking to understand and account for the impact of scientific research, and (2) fellow philosophers working in applied philosophy, environmental philosophy, and bioethics.

Quantum Correlations Analyzed Modally — in the branching space-times framework
Tomasz Placek, Jagiellonian University, Krakow, Poland, visiting at Columbia, NY
Thomas Müller, University of Konstanz, Germany
Tuesday, March 19, 2019
12:05 pm, 1117 Cathedral of Learning

Abstract: Quantum correlation experiments can give rise to puzzling correlations, as already remarked by Einstein, Podolsky and Rosen in their landmark 1935 paper. Such experiments are intricate spatio-temporal set-ups in which there is, as it were, a mismatch between local and global possibilities. Belnap’s branching space-times theory allows for analyzing the interplay of local and global possibilities, with probabilities understood as degrees of possibility. In this framework we will describe a class of non-local correlations, and its proper sub-species: quantum correlations. We will provide formal definitions of different classes of hidden variable models, and link these classes to the notion of signaling.

The History and Philosophical Significance of the Analog/Digital Distinction
Zed Adams, The New School for Social Research
Tuesday, March 26, 2019
12:05 pm, 1117 Cathedral of Learning

Abstract: The analog/digital distinction pervades contemporary discourse. According to the received view of this distinction, analog representations are continuous, whereas digital representations are discrete. The received view originates in mid-twentieth century computing (Von Neumann 1958; Small 2001; Kline 2015), but finds its clearest articulation and development in a series of influential philosophical accounts (Goodman 1968; Haugeland 1981; Dretske 1982). The received view is not without its critics, however: some have argued that it miscategorizes paradigmatic examples of analog representations as digital and vice versa. According to the contrarian view of this distinction, analog representations systematically covary with what they represent, whereas digital representations represent integers via a positional notation (Lewis 1971; Fodor and Block 1972; Maley 2011). In this paper, I argue that close attention to the historical context in which the distinction first emerged, as well as how it was subsequently invoked in contexts as diverse as biology, psychology, and metaphysics, helps to resolve the debate between the received and contrarian views, as well as helping us to appreciate what is philosophically at stake in such debates more generally.