Advances in molecular biological research in the latter half of the twentieth century have made the story of the gene vastly complicated: the more we learn about genes, the less sure we are of what a gene really is. Knowledge about the structure and functioning of genes abounds, but the gene has also become curiously intangible. This collection of essays renews the question: what are genes? Philosophers, historians and working scientists re-evaluate the question in this volume, treating the gene as (...) a focal point of interdisciplinary and international research. It will be of interest to professionals and students in the philosophy and history of science, genetics and molecular biology. (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)

In recent years geneticists have witnessed many significant observations which have seriously shaken the traditional concept of the gene. These specifically include the facts that (1) the boundaries of transcriptional units are far from clear; in fact, whole chromosomes if not the whole genome seem to be continuums of genetic transcription, (2) many examples of gene fusion are known, (3) likewise many examples of so-called encrypted genes are known in the organelle genomes of microbial eukaryotes and in prokaryotes, and (4) (...) in addition to the structure of the gene, its functional status can also be inheritable, and, further, (5) epigenetic extra-genomic modes of inheritance, called genetic restoration, seem to be a rather common phenomenon, meaning that organisms can sometimes rewrite their DNA on the basis of RNA messages inherited from generations past. I will briefly review these observations and discuss the difficulties of defining the gene, and then formulate a new view, which is called the relational or systemic concept of the gene. It has to be noted that genes assume their information content characteristics in the Shannonian sense as nucleotide sequences of DNA (or RNA). However, on the basis of this we cannot say anything about their information content in the semantic sense. The semantic information content of genes is context-dependent. Genes namely assume their biochemical characteristics usually only within living cells, their developmental characteristics only within living organisms, and their evolutionary characteristics only within populations of living organisms. (shrink)

A historical and critical analysis of the concept of the gene that attempts to provide new perspectives and metaphors for the transformation of biology and its philosophy.