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)

There is a paradox lying at the heart of the study of heredity. To understand the ways in which features are passed down from one generation to the next, we have to dig deeper and deeper into the ultimate nature of things - from organisms, to genes, to molecules. And yet as we do this, increasingly we find we are out of focus with our subjects. What has any of this to do with the living, breathing organisms with which we (...) started? Organisms are living. Molecules are not. How do we relate one to the other? In Genetic Analysis, one of the most important empirical scientists in the field in the twentieth century attempts, through a study of history and drawing on his own vast experience as a practitioner, to face this paradox head-on. His book offers a deep and innovative understanding of our ways of thinking about heredity. (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)

The ArgumentWhereas eugenics aspired to redeem the human species by forcing it to face the realities of its biological nature, Zionism aspired to redeem the Jewish people by forcing it to face the realities of its biological existence. The Zionists claimed that Jews maintained their ancient distinct “racial” identity, and that their regrouping as a nation in their homeland would have profound eugenic consequences, primarily halting the degeneration they fell prey to because of the conditions imposed on them in the (...) past. Some Zionists believed in a Lamarckian driven eugenics that expected the “normalization” of Jewish life styles to change their constitution. Others believed that transforming conditions would shift selective pressures exerted on the Jewish gene pool. (shrink)

Developments in the sequencing of whole genomes and in simultaneously surveying many thousands of transcription and translation products of specific cells have ushered in a conceptual revolution in genetics that rationally introduces top-down, holistic analyses. This emphasized the futility of attempts to reduce genes to structurally discrete entities along the genome, and the need to return to Johannsen's definition of a gene as 'something' that refers to an invariant entity of inheritance and development. We may view genes either as generic (...) terms for units of inheritance whose referents are pragmatic ad hoc and context-dependent, or as (epistemologically) representing entities of cell functions. It is cellular functions that determine the structural referents along the DNA. Structures that happened to secure specific functions that were essential for or conducive to the survival of cells were selected for. With natural selection being the etiological background of genes as functions, genes obtain again their theoretical role as intervening variables, abstractive variables that purely 'summarize' characters. The importance of DNA sequences is that of all possible phenotypes these are the most basic ones from which we can read off the genotype directly. (shrink)

This book offers a unique perspective on Zionism. The author, a geneticist by training, focuses on science, rather than history. He looks at the claims that Jews constitute a people with common biological roots. An argument that helps provide justification for the aspirations of this political movement dedicated to the return of the Jewish people to their homeland. His study explores two issues. The first considers the assertion that there is a biology of the Jews. The second deals with attempts (...) to integrate this idea into a consistent history. Both issues unfolded against the background of a romantic national culture of Western Europe in the 19th century: Jews, primarily from Eastern Europe, began to believe these notions and soon they took the lead in the re-formulation of Jewish and Zionist existence. The author does not intend to present a comprehensive picture of the biological literature of the origins of a people and the blood relations between them. He also recognizes that the subject is emotionally-loaded. The book does, however, present a profound mediation on three overlapping questions: What is special or unique to the Jews? Who were the genuine Jews? And how can one identify Jews? This volume is a revised and edited English version of Tzionut Vehabiologia shel Hayehudim, published in 2006. (shrink)

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)

In 1941/42 Konrad Lorenz suggested that Kant's transcendental categories ofa priori knowledge could be given an empirical interpretation in Darwinian material evolutionary terms: a priori propositional knowledge was an organ subject to natural selection for adaptation to its specific environments. D. Campbell extended the conception, and termed evolution a process of knowledge. The philosophical problem of what knowledge is became a descriptive one of how knowledge developed, the normative semantic questions have been sidestepped, as if the descriptive insights would automatically (...) resolve them. This came at a time when the traditional concept of knowledge as universally true, justified beliefs had been challenged by subjectivist, intercommunicative coherence frameworks. Much of the literature on evolutionary epistemology claimed that knowledge in general, and science as its epitome in particular, evolved along lines analogous to organic biological evolution. I refer here only to the view of knowledge as an extension of material biological evolution. These theories of evolutionary epistemology, contrary to the relativist notions of naturalized epistemology, adopted strict realist positions.Although there is no contention with the claim that biological evolution provided the raw material and the constraints for human knowledge, cognition is not knowledge and knowledge is not constrained by it beyond some trivial truisms. The view that sees evolution as a knowledge/cognition process is coercing a loosely defined term into the status of a phenotypic trait on which selection could act. This disregards the intricate many-to-many relationship between correlates of knowledge and biological capacities. But even if we grant the correlates of knowledge the status of selectable traits, the heritability of alternative phenotypes would be low and unpredictable due to the high, open-ended environmental malleability of such complex characters in the course of development. Such concepts are therefore biologically inconsequential. (shrink)

Contrary to Mendel, who introduced hybridization as a methodology for the study of selected discrete traits, de Vries conceived of organisms to be composed of discrete traits. This introduced into genetic research the dialectics of reductive analysis of genes as instrumental variables versus that of genes as the material atoms of heredity. The latter conception gained support with the analysis of mutations and eventually with high resolution analysis at the genetic and biochemical levels, as achieved in fungi and later in (...) bacteria and their viruses. Attempts to reduce "classical" genetics to "molecular" genetics turned out to be futile. However, this did not necessarily imply that these were two distinct theoretical approaches. On the contrary, it is argued that molecular genetics is an extension of phenomenological deduction, rather than being induction from molecular (DNA) causes to effects. Although conceptually systems direct development, methodologically individual inputs must be studied. (shrink)

Genetics was established on a strict particulate conception of heredity. Genetic linkage, the deviation from independent segregation of Mendelian factors, was conceived as a function of the material allocation of the factors to the chromosomes, rather than to the multiple effects (pleiotropy) of discrete factors. Although linkage maps were abstractions they provided strong support for the chromosomal theory of inheritance. Direct Cytogenetic evidence was scarce until X-ray induced major chromosomal rearrangements allowed direct correlation of genetic and cytological rearrangements. Only with (...) the discovery of the polytenic giant chromosomes in Drosophila larvae in the 1930s were the virtual maps backed up by physical maps of the genetic loci. Genetic linkage became a pivotal experimental tool for the examination of the integration of genetic functions in development and in evolution. Genetic mapping has remained a hallmark of genetic analysis. The location of genes in DNA is a modern extension of the notion of genetic linkage. (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.