Terms loaded with informational connotations are often employed to refer to genes and their dynamics. Indeed, genes are usually perceived by biologists as basically ‘the carriers of hereditary information.’ Nevertheless, a number of researchers consider such talk as inadequate and ‘just metaphorical,’ thus expressing a skepticism about the use of the term ‘information’ and its derivatives in biology as a natural science. First, because the meaning of that term in biology is not as precise as it is, for instance, in (...) the mathematical theory of communication. Second, because it seems to refer to a purported semantic property of genes without theoretically clarifying if any genuinely intrinsic semantics is involved. Biosemiotics, a field that attempts to analyze biological systems as semiotic systems, makes it possible to advance in the understanding of the concept of information in biology. From the perspective of Peircean biosemiotics, we develop here an account of genes as signs, including a detailed analysis of two fundamental processes in the genetic information system (transcription and protein synthesis) that have not been made so far in this field of research. Furthermore, we propose here an account of information based on Peircean semiotics and apply it to our analysis of transcription and protein synthesis. (shrink)

The present thesis explores some metaphysical issues concerning biochemical kinds and the relations between chemical and biological properties and phenomena. The main result of this thesis is that there is something sui generis about biochemical kinds. This result is motivated by two theoretical steps. The first is characterising biochemical functions as weakly emergent from the chemical structure [Chapter 3, Chapter 6]. The second is via an account for which biochemical kinds are natural categories [Chapter 4, Chapter 7]. The thesis comprises (...) four parts. Part I [Chapter 1, Chapter 2] aims to offer the methodological and conceptual tools that underpin this research. Chapter 1 presents the debate on the unity of science and the motivation of the research. Chapter 2 presents the account of natural kinds that will be used throughout the thesis. Part II [Chapter 3, Chapter 4] offers a detailed metaphysical analysis of the molecular gene. Chapter 3 argues that molecular genes are weakly emergent from nucleic acids. Chapter 4 argues that the category "molecular gene" can be deemed a natural kind, following the account presented in Chapter 2. Part III [Chapter 5, Chapter 6, Chapter 7] explores some of the themes related to biochemical kinds and generalises some of the results from Part II. Chapter 5 considers biochemical functions and how functional attribution should be interpreted for biochemical molecules. Chapter 6 considers the relation between biochemical functions and structure, spelt in terms of weak emergence and explores unity in biochemistry. Chapter 7 considers the topic of biochemical kinds per se and argues that biochemical kinds are natural categories. Part IV [Chapter 8] elucidates the main outcome and the implications that this research can have for future discussion in the philosophy and metaphysics of biochemistry and the unity of science. (shrink)

What is a gene? Does it represent a natural kind, or is it just a tool for genomics? A clear answer to these questions has been challenged by postgenomic discoveries. In response, I will argue that the gene can be deemed a natural kind as it satisfies some requirements for genuine kindhood. Specifically, natural kinds are projectible categories in our best scientific theories, and they represent nodes in the causal network of the world (as in Khalidi. Natural Categories and Human (...) Kinds: Classification in the Natural and Social Sciences. Cambridge University Press, Cambridge, 2013; Khalidi. Synthese 195: 1379–1396, 2018; Khalidi. Are Sexes Natural Kinds, In: Dasgupta S, Weslake B (eds) Current Controversies in Philoso-phy of Science. Routledge, New York, 2020; Khalidi. Philos Sci 88:1–21, 2021). In Sect. 2, I will present a brief history of the gene and the controversy over its status. In Sect. 3, I will introduce the account of natural kinds considered in this paper. In Sect. 4, I will first present the relevant definition of genes and how they can be classified. Then, I will argue that the gene can be considered a natural kind as it satisfies the criteria for natural kindhood. Section 5 concludes. (shrink)

This paper evaluates and criticises the developmental systems conception of evolution and develops instead an extension of the gene's eye conception of evolution. We argue (i) Dawkin's attempt to segregate developmental and evolutionary issues about genes is unsatisfactory. On plausible views of development it is arbitrary to single out genes as the units of selection. (ii) The genotype does not carry information about the phenotype in any way that distinguishes the role of the genes in development from that other factors. (...) (iii) There is no simple and general causal criterion which distinguishes the role of genes in development and evolution. (iv) There is, however, an important sense in which genes but not every other developmental factor represent the phenotype. (v) The idea that genes represent features of the phenotype forces us to recognise that genes are not the only, or almost the only, replicators. Many mechanisms of replication are involved in both development and evolution. (vi) A conception of evolutionary history which recognises both genetic and non-genetic replicators, lineages of replicators and interactors has advantages over both the radical rejection of the replicator/interactor distinction and the conservative restriction of replication to genetic replication. (shrink)

The identity and the existence of genes has been challenged by postgenomic discoveries. Specifically, the consideration of molecular and cellular phenomena in which genes are embedded has proved relevant for their understanding. In response to these challenges, I will argue that the complexity of genetic phenomena supports the weak emergence of genes from the DNA. In Section 2, I will expose what genes are taken to be in the postgenomic world. In Section 3, I will present the relevant account of (...) emergence. I consider weak emergence as in Franklin and Knox, for which a phenomenon is emergent when it displays novelty and robustness. In Section 4, I will argue that genes are weakly emergent since they are novel, improving explanations, and robust in respect to some perturbations. Then, I will conclude in Section 5 that genes’ emergence is a way to allow genes’ flexibility and context dependency, without compromising their existence. (shrink)

The purpose of this study is to interpret and qualitatively characterise the content in some research articles and evaluate cases of possible difference in meanings of the gene concept used. Using a reformulation of Hirst’s criteria of forms of knowledge, articles from five different sub-disciplines in biology were characterised according to knowledge project, methods used and conceptual contexts. Depending on knowledge project, the gene may be used as a location of recombination, a target of regulatory proteins, a carrier of regulatory (...) sequences, a cause in organ formation or a basis for a genetic map. Methods used range from catching wild birds and dissecting beetle larvae to growing yeast cells in 94 small wells as well as mapping of recombinants, doing statistical calculations, immunoblotting analysis of protein levels, analysis of gene expression with PCR, immunostaining of embryos and automated constructions of multi-locus linkage maps. The succeeding conceptual contexts focused around concepts as meiosis and chromosome, DNA and regulation, cell fitness and production, development and organ formation, conservation and evolution. These contextual differences lead to certain content leaps in relation to different conceptual schemes. The analysis of the various uses of the gene concept shows how differences in methodologies and questions entail a concept that escapes single definitions and “drift around” in meanings. These findings make it important to ask how science might use concepts as tools of specific inquiries and to discuss possible consequences for biology education. (shrink)

A hypothesis of genome structural evolution is explored. Rapid and cohesive alterations in genome organization are viewed as resulting from the dynamic and constrained interactions of chromosomal subsystem components. A combination of macromolecular boundary conditions and DNA element involvement in far-from-equilibrium reactions is proposed to increase the complexity of genomic subsystems via the channelling of genome turnover; interactions between subsystems create higher-order subsystems expanding the phase space for further genetic evolution. The operation of generic constraints on structuration in genome evolution (...) is suggested by i) universal, homoplasic features of chromosome organization and ii) the metastable nature of genome structures where lower-level flux is constrained by higher-order structures. Phenomena such as ‘genomic shock’, bursts of transposable element activity, concerted evolution, etc., are hypothesized to result from constrained systemic responses to endogenous/exogenous, micro/macro perturbations. The constraints operating on genome turnover are expected to increase with chromosomal structural complexity, the number of interacting subsystems, and the degree to which interactions between genomic components are tightly ordered. (shrink)

The beanbag genetics controversy can be traced from the dispute between Fisher and Wright, through Mayr''s influential promotion of the issue, to the contemporary units of selection debate. It centers on the claim that genic models of natural selection break down in the face of epistatic interactions among genes during phenotypic development. This claim is explored from both a conceptual and a quantitative point of view, and is shown to be defective on both counts.Firstly, an analysis of the controversy''s theoretical (...) origins demonstrates that this claim derives from a misinterpretation of the conceptual foundations of Fisher''s genetical theory of natural selection, and confounds his fundamentally different concepts of the average excess and average effect of a gene. Secondly, an extension of the genic approach is proposed which models the dynamics of selection among epistatically interacting complexes of many genes. Paradoxically, this preliminary, but fundamentally genic model provides quantitative support for some controversial qualitative claims regarding the evolutionary consequences of strong gene interactions made by opponents of genic selectionism, including Mayr''s theory of peripartric speciation. These findings foster hope that the proposed approach may eventually nudge the beanbag controversy out of its conceptual trenches into a more empirically oriented dialogue. (shrink)

Amidst the progress being made in the various (sub-)disciplines of the behavioural and brain sciences a somewhat neglected subject is the problem of how everything fits into one world and, derivatively, how the relation between different levels of discourse should be understood and to what extent different levels, domains, approaches, or disciplines are autonomous or dependent. In this paper I critically review the most recent proposals to specify the nature of interdiscourse relations, focusing on the concept of supervenience. Ideally supervenience (...) is a relation between different discourses which has all the advantages of reduction, but without its disadvantages. I apply the more abstract considerations to two concrete cases: schizophrenia and colour. Usually an interlevel or interdiscourse relation is seen as asymmetrical: the overlaying discourse depends on the underlying discourse (and not vice versa), where the out- or un-spoken assumption is that the ultimate underlying discourse is physical. Instead I argue that scientific categories referred to in interdiscourse relations are, ultimately, dependent on common sense categories and common sense normative criteria. It is the manifest categories and common sense ideas about what is reasonable and what is right that determine the relevant categorisations at the deeper, underlying levels. I suggest that the implications of this are not merely methodological or epistemological. (shrink)

In his critical notice, Rosenberg (1991) raises three objections to my evolutionary account of science: whether it is more than a week metaphor, the compatibility of my past objections to reduction and my current advocacy of viewing selection in terms of replication and interaction, and finally, the feasibility of identifying appropriate replicators and interactors in biological evolution, let alone conceptual evolution. I discuss each of these objections in turn.