  Given this context-dependence in what genes are considered to be and do, it seems that pluralism has become the order of the day, for genes as for species. Along these lines, John Dupré (2004) advocates “an atheoretical pluralism” that abandons any pretence to a “theoretical core to the concept”: simply, “a gene is any bit of DNA that anyone has reason to name and keep track of” (pp.  332–333).[15] Keller (2000) agrees that the theoretical importance of genes has faded; she writes: “it seems evident that the primacy of the gene as the core explanatory concept of biological structure and function is more a feature of the twentieth century than it will be of the twenty-first” (p. 9). She forecasts the emergence of new language; this is a situation for which Philip Kitcher believed molecular biology was ripe even 15 years ago when he wrote: “it is hard to see what would be lost by dropping talk of genes from molecular biology and simply discussing the properties of various interesting regions of nucleic acid” (1992, p. 130). Keller believes that gene-talk has served a purpose though, providing a flexibility which permits communication across those specific experimental practices within which “gene” attains precision. Hans-Jörg Rheinberger (2000) takes this argument one step further: gene concepts are not merely useful in spite of their ambiguity, they are useful in virtue of their ambiguity because, as “tools of research, they must reach out into the realm of what we do not yet know” (p. 223). He reminds us that this is nothing new: “The spectacular rise of molecular biology has come about without a comprehensive, exact, and rigid definition of what a gene is” (p. 222). Keller's and Rheinberger's views present an evident challenge to philosophical intuitions that scientific practice is furthered by arriving at precise definitions of basic concepts.