| This
project makes a science-philosophical study of the behavior and the evolution
of the genome, seen as a dynamic networksystem, and implies to analyse
the impact of self-organization and selection in these processes. Especially,
epigenetics and its relation to evolution is investigated via (1) a theoretical
analysis of the relevant literature in molecular genetics and evolutionary
theory and (2) an experimental study of transgenerational gene-expression
of an epigenetic regulated transgene in Arabidopsis thaliana. Further,
the historical-conceptual shift from 'epigenesis' to 'epigenetics' is
investigated in relation to the preformationist-debate during the 16th
-18th century. Whereas genetics refers to the study and mapping of linear
nucleotide sequences, 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 the DNA base sequence. In this sense, epigenetics -
as the term indicates - goes beyond genetics, thereby (1) leaving behind
the gene-centered view from within molecular biology itself, and (2) urging
bio-philosophers to change their focus from criticizing the central dogma
to evaluating new developments in molecular research. In the epigenetic
approach, a hierarchy of genomic contexts can be revealed, consisting
basically of an intracellular, an intercellular, and an organismic level.
The first explorations on the organismic 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 constitution. 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 genome and its consequences
for development and evolution. This "organism in the world" view fits
well with the philosophical tradition of Developmental Systems Theory,
although epigeneticists seek to enlarge the genetic picture of biology
by gradually expanding the range of molecular processes which influence
the genome, thereby decentralizing the sovereign role of the genome, without
loosing track of experimental demands. |
