According to Kuhn's speciation analogy, scientific specialisation is fundamentally analogous to biological speciation. In this paper, we extend Kuhn's original language-centred formulation of the speciation analogy, to account for episodes of scientific specialisation centred around methodological differences. Building upon recent views in evolutionary biology about the process of speciation by genetic divergence, we will show how these methodology-centred episodes of scientific specialisation can be understood as cases of specialisation driven by value divergence. We will apply our model of specialisation by (...) value divergence to an episode of methodology-centred scientific specialisation: the emergence of molecular biology. (shrink)

Philosophers have proposed various kinds of relations between Mendelian genetics and molecular biology: reduction, replacement, explanatory extension. This paper argues that the two fields are best characterized as investigating different, serially integrated, hereditary mechanisms. The mechanisms operate at different times and contain different working entities. The working entities of the mechanisms of Mendelian heredity are chromosomes, whose movements serve to segregate alleles and independently assort genes in different linkage groups. The working entities of numerous mechanisms of molecular biology are larger (...) and smaller segments of DNA plus related molecules. Discovery of molecular DNA mechanisms filled black boxes that were noted, but unilluminated, by Mendelian genetics. (shrink)

An assessment is offered of the recent debate on information in the philosophy of biology, and an analysis is provided of the notion of information as applied in scientific practice in molecular genetics. In particular, this paper deals with the dependence of basic generalizations of molecular biology, above all the ‘central dogma’, on the so-called ‘informational talk’ (Maynard Smith [2000a]). It is argued that talk of information in the ‘central dogma’ can be reduced to causal claims. In that respect, the (...) primary aim of the paper is to consider a solution to the major difficulty of the causal interpretation of genetic information: how to distinguish the privileged causal role assigned to nucleic acids, DNA in particular, in the processes of replication and protein production. A close reading is proposed of Francis H. C. Crick's On Protein Synthesis (1958) and related works, to which we owe the first explicit definition of information within the scientific practice of molecular biology. Introduction 1.1 The basic questions of the information debate 1.2 The causal interpretation (CI) of biological information and Crick's ‘central dogma’ Crick's definitions of genetic information The main requirement for (CI) Types of causation in molecular biology 4.1 Structural causation in molecular biology 4.2 Nucleic acids as correlative causal factors The ‘central dogma’ without the notion of information Concluding remarks This is a new version of this article as there were errors in the abstract and full text in the previous version. (shrink)

A notion of experimental series is developed, in which experiments or experimental sets are connected through experimental suggestions arising from previous experimental outcomes. To that end, the justification of Howard Temin’s DNA provirus hypothesis is examined. The hypothesis originated with evidence from two exploratory experimental sets on an oncogenic virus and was substantiated by including evidence from three additional experimental sets. Collectively these sets comprise an experimental series and the accumulative evidence from the series was adequate to justify the hypothesis (...) by persuading the virology community of its veracity. The notion of crucial experiment is also discussed in terms of experimental series. (shrink)

In 1958, Francis Crick distinguished the flow of information from the flow of matter and the flow of energy in the mechanism of protein synthesis. Crick’s claims about information flow and coding in molecular biology are viewed from the perspective of a new characterization of mechanisms and from the perspective of information as holding a key to distinguishing work in molecular biology from that of biochemistry in the 1950s–1970s . Flow of matter from beginning to end does not occur in (...) the protein synthesis mechanism; flow of information does. The flow of information and coding in molecular biological mechanisms are distinguished, on the one hand, from formal information theory, and, on the other, from information as used in cognitive neuroscience, where information and representation are often coupled. (shrink)

During the 1960s, Howard M. Temin (1934-1994), dared to advocate a "heretical" hypothesis that appeared to be at variance with the central dogma of molecular biology, understood by many to imply that information transfer in nature occurred only from DNA to RNA. Temin's provirus hypothesis offered a simple explanation of both virus replication and viral-induced cancer and stated that Rous sarcoma virus, an RNA virus, is replicated via a DNA intermediate. Popular accounts of this scientific episode, written after the discovery (...) of an RNA-directed DNA polymerase in 1970, tend to describe the reaction to his proposition as ardent opposition. Typically these accounts use a 'molecular biology' standpoint emphasizing the central dogma's part in its rejection. In this article, however, this episode will be examined from a joint perspective of virology and experimental cancer research. From this perspective it is clear that Temin's work was well within the epistemological and methodological boundaries of virology and cancer research. Still, scientists did have reasons to doubt the provirus hypothesis, but these do not seem to be good enough to either justify an account that portrays Temin as a renegade or his ideas as heretical. (shrink)