The organism: A crucial genomic context in molecular epigenetics?

Whereas genetics refers to the study and mapping of linear nucleotide seque nces, their mutations and inheritance, epigenetics refers to the structural organization and evolution of the genome. Epigenetic studies indicate that not all heritable information leading to the phenotype is "inscribed" in t he DNA base sequence. In this sense, epigenetics - as the term indicates - goes beyond genetics, thereby (1) leaving behind the gene-centered view fro m within molecular biology itself, and (2) urging bio-philosophers to chang e their focus from criticizing the central dogma to evaluating new developm ents in molecular research. In the epigenetic approach, a hierarchy of geno mic contexts can be revealed, consisting basically of an intracellular, an intercellular, and an organismic level. The first explorations on the organ ismic level suggest that under certain conditions the somatic constitution of the organism and how it stands in close interaction with its environment are to be taken into account as factors influencing the genomic constituti on. Depending on the specificity of these conditions, the organism and its history and actuality can be seen as a crucial genomic context - leading to a more complex perception of the local dynamics and the structure of the g enome and its consequences for development and evolution. This "organism in the world" view fits well with the philosophical tradition of Developmenta l Systems Theory, although epigeneticists seek to enlarge the genetic pictu re biology by gradually expanding the range of molecular processes which in fluence the genome, thereby decentralizing the sovereign role of the genome , without loosing track of experimental demands.