ABSTRACT

Taken as a composite, the meaning of the composite term genetic program — offered (or taken for granted) as the name of an explanatory theory of developmental biology — simultaneously depends upon and underwrites the particular presumption that a “plan of procedure” for development is itself written in the sequence of nucleotide bases. Is this presumption correct? Certainly, it is almost universally taken for granted, but I want to argue that, at best, it is misleading, and at worst, simply false: To the extent that we may speak at all of a developmental program, or of a set of instructions for development, in contradistinction to the data or resources for such a program, current research obliges us to acknowledge that these instructions are not written into the DNA itself (or at least, are not all written in the DNA), but rather are distributed throughout the fertilized egg. Indeed, if the distinction between program and data is to have any meaning in biology, it has become abundantly clear that it does not align (as had earlier been assumed) either with a distinction between “genetic” and “epigenetic,” or with the precursor distinction between nucleus and cytoplasm. I want to suggest that the notion of genetic program depends upon, and sustains, a fundamental category error in which two independent distinctions, one between genetic and epigenetic, and the other, between program and data, are pulled into mistaken alignment. The net effect of such alignment is to reinforce two outmoded associations: on the one hand, between genetic and active, and, on the other, between epigenetic and passive.