A Critique of Pure (Genetic) Information

Genesis of the Gene 31
solved problematics of embryology to fare for themselves (Allen 1985,
Darden 1991). As embryologists fractured the cell into nucleus and cytoplasm,
so the life sciences fractured into a center and periphery, with
genetics becoming the center and with the legacy of developmentally (and
organizationally) oriented biology relegated to the periphery. Philosophically,
it will be important to see how many central problems were
banished to the margins and yet naively thought to be solved (or almost
solved) in the name of the gene. Johannsen, with much perspicuity, anticipated
the likely misconstrual of the genetic perspective. After reconstructing
this tortuous journey I will return to take a closer look at
Johannsen’s insightful perspective.
The earliest experimental attempt to locate the Anlagen at a subcellular
level began not with the chromosome or even nucleus but rather with
the nineteenth-century hypothesis of “cytoplasmic anlagen” put forward
by Wilhelm His (Gilbert 1978). C. O. Whitman, following His, believed
organismal development could be analyzed by tracing the path of cell
lineages from their origins in cytoplasmic Anlagen. Not long after His,
Nägeli proposed the existence of an “idioplasm,” later elaborated by
Weismann, consisting of nested, hierarchically organized, particulate
units that directed development. Nägeli was nonconmittal, however, as
to where the idioplasm would be located. With the accumulated cytological
work on chromosomes and the strong impression made by the
observation that chromosome number and morphology remain constant
across generations, Oscar Hertwig, Weismann, Kölliker, and others postulated
that the chromosomes were the site of the putative idioplasm
(Sapp 1987).
That party lines among embryologists in the 1890s were partitioned
along the boundary of the cell nucleus was largely contingent. Surely
some form of nucleocytoplasmic egalitarianism could also have found a
place within the logical space of possibilities. However, the nucleus
versus cytoplasm divide came to define a rather intractable opposition
over what was going to count as the proper stuff of heredity.
Wilhelm Roux, following Weismann, championed a “mosaic hypothesis,”
which, had it been successful, would have enabled the nuclearidioplasm
theory to unite development and inheritance within a
single, particulate-preformationistic model. According to the mosaic