. Molecular Biology and General Philosophy of ScienceIn addition to analyzing key concepts in the field, philosophers have employed case studies from molecular biology to address more general issues in the philosophy of science. The issue of reduction was addressed by considering whether classical genetics had been reduced to molecular biology. Cases from molecular biology have also been used to analyze the relationship between laws and explanation (see also the entry on philosophy of biology). For each of these philosophical issues, it will be argued, evidence from molecular biology directs philosophical attention toward understanding the concept of a mechanism for addressing the topic.
Theory Reduction and Integration of FieldsReflecting on the historical origins of molecular biology discussed above, it should come as no surprise that the field appeared to many philosophers of science to offer an ideal case of reduction. Molecular biology emerged out of the search for the structure and function of the gene, so might the older field of classical genetics be (or have been) simply reduced to a successor—molecular biology?
Classical genetics had two laws, which, at first, seemed likely candidates for reduction to (derivation from) molecular laws. Based on patterns of inheritance of characters during breeding experiments, classical geneticists inferred regularities in the behavior of genes. These regularities were captured in Mendel's laws of segregation and independent assortment of genes in different linkage groups (as described in Section 1.1 above). The formal reduction of classical genetics to molecular biology required that these classical laws be logically deduced from laws of molecular biology. However, it was not possible to identify anything in molecular biology that was called a “law” or that played a role sufficient to allow logical derivation of Mendel's laws. Alternative analyses of the relation between classical genetics and molecular biology have included claims of replacement, informal reduction, explanatory extension, relations among practices, as well analysis of different mechanisms investigated in the two fields.