This paper surveys recent philosophy of biology. It aims to introduce outsiders to the field to the recent literature (which is reviewed in the footnotes) and the main recent debates. I concentrate on three of these: recent critiques of the replicator/vehicle distinction and its application to the idea of the gene as the unit of section; the recent defences of group selection and the idea that standard alternatives to group selection are in fact no more than a disguised form of (...) group selection; and recent ideas on the role of selection in evolution, especially the role of selection in structuring the large-scale history of life. The paper connects philosophy of biology to some more general problems in the philosophy of science, and concludes with a few suggestions about unfinished business. (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)

Molecular Weismannism is the claim that: “In the development of an individual, DNA causes the production both of DNA (genetic material) and of protein (somatic material). The reverse process never occurs. Protein is never a cause of DNA”. This principle underpins both the idea that genes are the objects upon which natural selection operates and the idea that traits can be divided into those that are genetic and those that are not. Recent work in developmental biology and in philosophy of (...) biology argues that an acceptance of Molecular Weismannism requires the tacit assumption that genetic causes are different in kind from other developmental causes. They argue that if this assumption proves to be unwarranted then we should abandon, not just gene selectionism and gene centred functional solutions to the units of selection problem, but also the very notion that there is any such thing as a “genetic trait”. A group of possible causal distinctions (proximity, ultimacy and specificity) are explored and found wanting. It is argued that an extended version of information theory, while not strong enough to support Molecular Weismannism, will support both the claim that traits can be divided into those that are genetic and those that are not as well as the claim that there is good reason to privilege genetic causes within evolutionary and developmental explanations. The outcome of this for the units of selection debate is explored. (shrink)

The Developmental Systems approach to evolution is defended against the alternative extended replicator approach of Sterelny, Smith and Dickison (1996). A precise definition is provided of the spatial and temporal boundaries of the life-cycle that DST claims is the unit of evolution. Pacé Sterelny et al., the extended replicator theory is not a bulwark against excessive holism. Everything which DST claims is replicated in evolution can be shown to be an extended replicator on Sterelny et al.s definition. Reasons are given (...) for scepticism about the heuristic value claimed for the extended replicator concept. For every competitive, individualistic insight the replicator theorist has a cooperative, systematic blindspot. (shrink)

The 'developmental systems' perspective in biology is intended to replace the idea of a genetic program. This new perspective is strongly convergent with recent work in psychology on situated/embodied cognition and on the role of external 'scaffolding' in cognitive development. Cognitive processes, including those which can be explained in evolutionary terms, are not 'inherited' or produced in accordance with an inherited program. Instead, they are constructed in each generation through the interaction of a range of developmental resources. The attractors which (...) emerge during development and explain robust and/or widespread outcomes are themselves constructed during the process. At no stage is there an explanatory stopping point where some resources control or program the rest of the developmental cascade. 'Human nature' is a description of how things generally turn out, not an explanation of why they turn out that way. Finally, we suggest that what is distinctive about human development is its degree of reliance on external scaffolding. (shrink)

The paper argues for a pragmatic account of genetic explanation. This is to say that when a disease or other trait is termed genetic, the reasons for singling out genes as causes over other, also necessary, genetic and nongenetic conditions are not wholly theoretical but include pragmatic dimensions. Whether the explanation is the presence of a trait in an individual or differences in a trait among individuals, genetic explanations are context-dependent in three ways: they are relative to a causal background (...) of genetic and nongenetic factors; they are relative to a population; and they are relative to the present state of knowledge. Criteria like causal priority, nonstandardness, and causal efficacy that purport to distinguish objectively between genetic causes and nongenetic conditions either incorporate pragmatic elements or fail for other reasons. When the pragmatic dimensions of genetic explanations are recognized, we come to understand the current phenomenon of geneticization to be a reflection of increased technological capacities to manipulate genes in the laboratory, and potentially the clinic, rather than theoretical progress in understanding how diseases and other traits arise. This calls into question the value of the search for theoretical definitions of designations like genetic disease or genetic susceptibility as directives for action. (shrink)

Sober (1992) has recently evaluated Brandon's (1982, 1990; see also 1985, 1988) use of Salmon's (1971) concept of screening-off in the philosophy of biology. He critiques three particular issues, each of which will be considered in this discussion.

The vagueness or imprecision of ‘the normal’ allows it to be exploited for various purposes and political ends. It is conspicuous in both medicine and athletics; I am going to try to say something about the normal in each of these areas. In medicine the idea of the normal is often deployed in understanding what constitutes disease and hence, as some see it, in determining the role of physicians, in determining what is or ought to be covered by insurance, and (...) in underwriting certain views on social justice. In athletics the use of performance enhancing substances raises different sorts of questions about the normal, especially when it comes to deciding what constitutes an enhancement and which enhancements, if any, are acceptable. (shrink)

How does a complex organism develop from a relatively simple, homogeneous mass? The usual answer is: through the execution of species-specific genetic instructions specifying the development of that organism. Commentators are sometimes sceptical of this usual answer, but of course not all commentators. Some biologists refer to master control genes responsible for the activation of all the genes responsible for every aspect of organismal development; and some philosophers, most notoriously Rosenberg, buy this claim hook, line, and sinker. Here I explore (...) both the seeming plausibility of the usual position, and also its ultimate inadequacy. (shrink)