Philosophers and historians of biology have argued that genes are conceptualized differently in different fields of biology and that these differences influence both the conduct of research and the interpretation of research by audiences outside the field in which the research was conducted. In this paper we report the results of a questionnaire study of how genes are conceptualized by biological scientists at the University of Sydney, Australia. The results provide tentative support for some hypotheses about conceptual differences between different (...) fields of biological research. (shrink)

In 1936, Frank Macfarlane Burnet published a paper entitled "Induced lysogenicity and the mutation of bacteriophage within lysogenic bacteria," in which he demonstrated that the introduction of a specific bacteriophage into a bacterial strain consistently and repeatedly imparted a specific property – namely the resistance to a different phage – to the bacterial strain that was originally susceptible to lysis by that second phage. Burnet's explanation for this change was that the first phage was causing a mutation in the bacterium (...) which rendered it and its successive generations of offspring resistant to lysogenicity. At the time, this idea was a novel one that needed compelling evidence to be accepted. While it is difficult for us today to conceive of mutations and genes outside the context of DNA as the physico-chemical basis of genes, in the mid 1930s, when this paper was published, DNA's role as the carrier of hereditary information had not yet been discovered and genes and mutations were yet to acquire physical and chemical forms. Also, during that time genes were considered to exist only in organisms capable of sexual modes of replication and the status of bacteria and viruses as organisms capable of containing genes and manifesting mutations was still in question. Burnet's paper counts among those pieces of work that helped dispel the notion that genes, inheritance and mutations were tied to an organism's sexual status. In this paper, I analyze the implications of Burnet's paper for the understanding of various concepts – such as "mutation," and "gene," – at the time it was published, and how those understandings shaped the development of the meanings of these terms and our modern conceptions thereof. (shrink)

William Bateson vigorously objected to the assumptions within the chromosome theory of heredity proposed by T. H. Morgan because he perceived inadequate experimental data that could substantiate the theory. Those objections were largely resolved by 1921, and Bateson reluctantly accepted the basic assumption that chromosomes carried the genetic factors from one generation to the next. Bateson's own research at that time on developmental genetics seemed out of touch with the general tone of the genetics field, and the chromosome theory did (...) not provide illuminating mechanisms that elucidated phenomena such as plant variegations or chimeras. Bateson imagined a general theory of heredity and development based on vortices and waves, concepts he borrowed from contemporary physics. For decades he sought to devise an intellectually and aesthetically satisfying theory to eventually explain evolution in genetic terms, but his aspirations remained unfulfilled when he died in 1926. (shrink)

Resumo: A partir de uma análise sobre a utilização das biotecnologias médicas, este artigo pretende compreender como a disseminação de uma lógica e um discurso "informacional", na área de saúde, mascaram as intervenções médicas efetuadas no corpo humano. Argumenta-se que frequentemente as práticas biotecnológicas são tratadas como meras relações linguísticas, como se não fossem operações de carne e sangue realizadas nos corpos. Para abordar a forma como essa lógica se processa, será feita, neste texto, uma breve discussão sobre como as (...) disputas em torno do que são, e como operam os genes, acabam por reforçar um paradigma informacional, ainda que tal resolução não seja amparada pelas evidências empíricas, mas em metáforas bem-sucedidas.: Starting with an analysis of the use of medical biotechnology, this article aims to understand how medical interventions in the human body are masked by a certain logic and by an "informational" discourse on health care. We argue that biotechnological practices are often treated as linguistic relations, as if they were not flesh and blood operations on bodies. To address how this logic is processed, we discuss how disputes over the nature and functioning of genes end up strengthening an informational paradigm that is not based on empirical evidence, but rather on successful metaphors. (shrink)

According to a recent suggestion, the names of gene taxa should be conceived of as referring to individuals with concrete genes as their parts, just as the names of biological species are often understood as denoting individuals with organisms as their parts. Although prima facie this suggestion might advance the debate on gene concepts in a similar way as the species-are-individuals thesis advanced the debate on species concepts, I argue that the principal arguments in support of the gene-individuality thesis are (...) much less compelling than the parallel arguments in the species case. In addition, I argue that the notion of biological function invoked in the gene-individuality thesis (selected effect) is not the one that biologists actually use when individuating genes. Contra the gene-individuality thesis, I argue that gene names refer to kinds, defined primarily (though not exclusively) by causal-role functions. (shrink)

Extrapolation from a well-understood base population to a less-understood target population can fail if the base and target populations are not sufficiently similar. Differences between laboratory mice and humans, for example, can hinder extrapolation in medical research. Mice that carry a partial or complete human physiological system, known as humanized mice, are supposed to make extrapolation more reliable by simulating a variety of human diseases. But what justifies our belief that these mice are similar enough to their human counterparts to (...) simulate human disease? I argue that, unless three requirements are met in the process of humanizing mice, very little does. My requirements are not meant to provide necessary and sufficient conditions that guarantee a particular outcome. Instead, they serve as a heuristic for guiding scientific judgments involving extrapolation. In developing each requirement, I engage with philosophical issues concerning the nature of model-based science and the mechanistic approach (and its limits) to making generalizations in the life sciences. (shrink)

While the definition of the ‘genotype’ has undergone dramatic changes in the transition from classical to molecular genetics, the definition of the ‘phenotype’ has remained for a long time within the classical framework. In addition, while the notion of the genotype has received significant attention from philosophers of biology, the notion of the phenotype has not. Recent developments in the technology of measuring gene-expression levels have made it possible to conceive of phenotypic traits in terms of levels of gene expression. (...) We demonstrate that not only has this become possible but it has also become an actual practice. This suggests a significant change in our conception of the phenotype: as in the case of the ‘genotype’, phenotypes can now be conceived in quantitative and measurable terms on a comprehensive molecular level. We discuss in what sense gene expression profiles can be regarded as phenotypic traits and whether these traits are better described as a novel concept of phenotype or as an extension of the classical concept. We argue for an extension of the classical concept and call for an examination of the type of extension involved. (shrink)

Advocates of an ‘extended evolutionary synthesis’ have claimed that standard evolutionary theory fails to accommodate epigenetic inheritance. The opponents of the extended synthesis argue that the evidence for epigenetic inheritance causing adaptive evolution in nature is insufficient. We suggest that the ambiguity surrounding the conception of the gene represents a background semantic issue in the debate. Starting from Haig’s gene-selectionist framework and Griffiths and Neumann-Held’s notion of the evolutionary gene, we define senses of ‘gene’, ‘environment’, and ‘phenotype’ in a way (...) that makes them consistent with gene-centric evolutionary theory. We argue that the evolutionary gene, when being materialized, need not be restricted to nucleic acids but can encompass other heritable units such as epialleles. If the evolutionary gene is understood more broadly, and the notions of environment and phenotype are defined accordingly, current evolutionary theory does not require a major conceptual change in order to incorporate the mechanisms of epigenetic inheritance. _1_ Introduction _2_ The Gene-centric Evolutionary Theory and the ‘Evolutionary Gene’ _2.1_ The evolutionary gene _2.2_ Genes, phenotypes, and environments _3_ Epigenetic Inheritance and the Gene-Centred Framework _3.1_ Treating the gene as the sole heritable material? _3.2_ Epigenetics and phenotypic plasticity _4_ Conclusion. (shrink)

Genetic information is becoming increasingly used in modern life, extending beyond medicine to familial history, forensics and more. Following this expansion of use, the effect of genetic information on people’s identity and ultimately people’s quality of life is being explored in a host of different disciplines. While a multidisciplinary approach is commendable and necessary, there is the potential for the multidisciplinarity to produce conceptual misconnection. That is, while experts in one field may understand their use of a term like ‘gene’, (...) ‘identity’ or ‘information’ for experts in another field, the same term may link to a distinctly different concept. These conceptual misconnections not only increase inefficiency in complex organisational practices, but can also have important ethical, legal and social consequences. This paper comes at the problem of conceptual misconnection by clarifying different uses of the terms ‘gene’, ‘identity’ and ‘information’. I start by looking at three different conceptions of the gene; the Instrumental, the Nominal and the Postgenomic Molecular. Secondly, a taxonomy of four different concepts of identity is presented; Numeric, Character, Group and Essentialised, and their use is clarified. A general concept of Information is introduced, and finally three distinct kinds of information are described. I then introduce Concept Creep as an ethical problem that arises from conceptual misconnections. The primary goal of this paper is to reduce the potential for conceptual misconnection when discussing genetic identity and genetic information. This is complimented by three secondary goals—1) to clarify what a conceptual misconnection is, 2) to explain why clarity of use is particularly important to discussions of genes, identity and information and 3) to show how concept creep between different uses of genetic identity and genetic information can have important ethical outcomes. (shrink)

We outline three very different concepts of the gene—instrumental, nominal, and postgenomic. The instrumental gene has a critical role in the construction and interpretation of experiments in which the relationship between genotype and phenotype is explored via hybridization between organisms or directly between nucleic acid molecules. It also plays an important theoretical role in the foundations of disciplines such as quantitative genetics and population genetics. The nominal gene is a critical practical tool, allowing stable communication between bioscientists in a wide (...) range of fields grounded in well-defined sequences of nucleotides, but this concept does not embody major theoretical insights into genome structure or function. The post-genomic gene embodies the continuing project of understanding how genome structure supports genome function, but with a deflationary picture of the gene as a structural unit. This final concept of the gene poses a significant challenge to conventional assumptions about the relationship between genome structure and function, and between genotype and phenotype. (shrink)

Experimental philosophy of science gathers empirical data on how key scientific concepts are understood by particular scientific communities. In this paper we briefly describe two recent studies in experimental philosophy of biology, one investigating the concept of the gene, the other the concept of innateness. The use of experimental methods reveals facts about these concepts that would not be accessible using the traditional method of intuitions about possible cases. It also contributes to the study of conceptual change in science, which (...) we understand as the result of a form of conceptual ecology, in which concepts become adapted to specific epistemic niches. (shrink)

In earlier work I have claimed that emotion and some emotions are not `natural kinds'. Here I clarify what I mean by `natural kind', suggest a new and more accurate term, and discuss the objection that emotion and emotions are not descriptive categories at all, but fundamentally normative categories.

Definitions of the term gene typically superimpose molecular genetics onto Mendelism. What emerges are persistent attempts to regard the gene as a unit of structure and/or function, language that creates multiple meanings for the term and fails to acknowledge the diversity of gene architecture. I argue that coherence at the molecular level requires abandonment of the classical unit concept and recognition that a gene is constructed from an assemblage of domains. Hence, a domain set (1) conforms more closely to empirical (...) evidence for genetic organization of DNA regions capable of transcription and (2) has ontological properties lacking in the traditional unit definition. (shrink)

The dialectic discourse of the ‘gene’ as the unit of heredity deduced from the phenotype, whether an intervening variable or a hypothetical construct, appeared to be settled with the presentation of the molecular model of DNA: the gene was reduced to a sequence of DNA that is transcribed into RNA that is translated into a polypeptide; the polypeptides may fold into proteins that are involved in cellular metabolism and structure, and hence function. This path turned out to be more bewildering (...) the more the regulation of products and functions were uncovered in the contexts of integrated cellular systems. Philosophers struggling to define a unified concept of the gene as the basic entity of genetics confronted those who suggested several different ‘genes’ according to the conceptual frameworks of the experimentalists. Researchers increasingly regarded genes de facto as generic terms for describing their empiric data, and with improved DNA-sequencing capacities these entities were as a rule bottom-up nucleotide sequences that determine functions. Only recently did empiricists return to discuss conceptual considerations, including top-down definitions of units of function that through cellular mechanisms select the DNA sequences which comprise ‘genomic-footprints’ of functional entities. (shrink)

Mendel's work in hybridization is ipso facto a study in inheritance. He is explicit in his interest to formulate universal generalizations, and at least in the case of the independent segregation of traits, he formulated his conclusions in the form of a law. Mendel did not discern, however, the inheritance of traits from that of the potential for traits. Choosing to study discrete non-overlapping traits, this did not hamper his efforts.

The encounter between the Darwinian theory of evolution and Mendelism could be resolved only when reductionist tools could be applied to the analysis of complex systems. The instrumental reductionist interpretation of the hereditary basis of continuously varying traits provided mathematical tools which eventually allowed the construction of the Modern Synthesis of the theory of evolution.When genotypic as well as environmental variance allow the isolation of parts of the system, it is possible to apply Mendelian reductionism, that is , to treat (...) the phenotypic trait as if ti causally determined by discrete genes for the trait. howeverm such a beanbag genetics approach obscures the system's eye-view. The concept of heritability, defined as the proportion of the total phenotypic variance due to (additive) hereditary variation, asserts that genetic elements have discrete effects; but by relating to the genotypic variance, it avoids the trap of reffering to genes for characters. (shrink)

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 discussion presents a framework of concepts that is intended to account for the rationality of semantic change and variation, suggesting that each scientific concept consists of three components of content: 1) reference, 2) inferential role, and 3) the epistemic goal pursued with the concept’s use. I argue that in the course of history a concept can change in any of these components, and that change in the concept’s inferential role and reference can be accounted for as being rational relative (...) to the third component, the concept’s epistemic goal. This framework is illustrated and defended by application to the history of the gene concept. It is explained how the molecular gene concept grew rationally out of the classical gene concept despite a change in reference, and why the use and reference of the contemporary molecular gene concept may legitimately vary from context to context. (shrink)

The purpose of this article is to update and defend syntax-based gene concepts. I show how syntax-based concepts can and have been extended to accommodate complex cases of processing and gene expression regulation. In response to difficult cases and causal parity objections, I argue that a syntax-based approach fleshes out a deflationary concept defining genes as genomic sequences and organizational features of the genome contributing to a phenotype. These organizational features are an important part of accepted molecular explanations, provide the (...) theoretical basis for a large number of experimental techniques and practical applications, and play a crucial role in in annotating the genome, deriving predictions and constructing bioinformatics models. (shrink)

Ongoing empirical discoveries in molecular biology have generated novel conceptual challenges and perspectives. Philosophers of biology have reacted to these trends when investigating the practice of molecular biology and contributed to scientific debates on methodological and conceptual matters. This article reviews some major philosophical issues in molecular biology. First, philosophical accounts of mechanistic explanation yield a notion of explanation in the context of molecular biology that does not have to rely on laws of nature and comports well with molecular discovery. (...) Second, reductionism continues to be debated and increasingly be rejected by scientists. Philosophers have likewise moved away from reduction toward integration across fields or integrative explanations covering several levels of organization. Third, although the gene concept has undergone substantial transformation and even fragmentation, it still enjoys widespread use by molecular biologists, which has prompted philosophers to understand the empirical reasons for this. At the same time, it has been argued the notion of ‘genetic information’ is largely an empty metaphor, which generates the illusion of explanatory understanding without offering an adequate explanation of molecular and developmental mechanisms. (shrink)

The historian Raphael Falk has described the gene as a ‘concept in tension’ (Falk 2000) – an idea pulled this way and that by the differing demands of different kinds of biological work. Several authors have suggested that in the light of contemporary molecular biology ‘gene’ is no more than a handy term which acquires a specific meaning only in a specific scientific context in which it occurs. Hence the best way to answer the question ‘what is a gene’, and (...) the only way to provide a truly philosophical answer to that question is to outline the diversity of conceptions of the gene and the reasons for this diversity. In this essay we draw on the extensive literature in the history of biology to explain how the concept has changed over time in response to the changing demands of the biosciences . Finally, we outline some of the conceptions of the gene current today. The seeds of change are implicit in many of those current conceptions and the future of the gene concept looks set to be at as turbulent as the past. (shrink)

The paper describes the change from molecular genetics to postgenomic biology. It focuses on phenomena in the regulation of gene expression that provide a break with the central dogma, according to which sequence specificity for a gene product must be template derived. In its place we find what is called here ‘constitutive molecular epigenesis’. Its three classes of phenomena, which I call sequence ‘activation’, ‘selection’ and ‘creation’, are exemplified by processes such as transcriptional activation, alternative cis- and trans-splicing, and RNA (...) editing. These phenomena support the following main theses of the paper: 1. Other molecular resources share the causal role of ‘genes’: the ‘causal specificity’ for the linear sequence of any gene product is distributed between the coding sequence, cis-acting sequences, trans-acting factors, environmental signals, and the contingent history of the cell (the cellular code) (thesis of distributed causal specificity). 2. These multiple and overlapping processing and targeting mechanisms amplify the repertoire of RNA and protein products specified through the eukaryotic genome, expanding the possibilities specified by the literal code of DNA (thesis of genetic underdeterminism). 3. These mechanisms of gene expression change the focus of postgenomic research from single molecules and their molecular, biochemical and intrinsic function to their cellular, constituent, component or contextual function due to their recruitment and organization in complex cellular networks. In other words, all agents involved in the regulation of gene expression, including DNA, must interact with other agents to achieve full specificity, which is imposed by regulated recruitment and combinatorial control (theses of regulated recruitment and of system analysis). I conclude from these three main theses that the complexity of higher organisms lies not in its number of genes but in the flexibility, versatility and reactivity of its whole genome. (shrink)