Biology Reference
In-Depth Information
Weiss supported his theory with empirical observations.
Territories in an embryo can be defined in the knowledge of exactly
what they will become at a later stage of its development. In any
embryo the same territory will become the same part, but there is
a lack of determination as to what the parts (the cells) inside this
territory will become (SL pp. 21-22). A particular part in one
embryo does not have exactly the same future inside the territory
as that same part in another embryo. This phenomenon would be
found at every level of organisation, e.g. in cells as regards their
molecular constituents. Cells of the same type are globally identical
but there is microscopic variability between them. For Weiss, these
observations reveal a general principle “
… of determinacy in the
gross despite demonstrable indeterminacy in the small for practi-
cally any level and area of the life sciences
” (SL pp. 21-22). Macro-
determinism of the global structure of the organism would
progressively constrain the lower levels without their being totally
determined in detail (SL pp. 23-24). In this process, the macro-
determinism would not be reduced to the properties of the parts of
the organism (the tissues, cells, molecules): on the contrary, the
macroscopic structures and properties would emerge during a self-
organisation process (SL pp. 29-35).
To explain what he means by self-organisation, Weiss uses the
photograph of a vast beach taken one sunny Sunday when there
were a lot of people bathing there (Fig.13). The beach is marked at
the top of the photo by the edge of the sea which is slightly wavy
and at the bottom by a straight road. The people look like dots
which are denser near the water's edge and in various places corre-
sponding to restaurants or different attractions. If the same photo
were taken on another Sunday that was just as sunny, the picture
would appear to be identical although in detail each dot (each
bather) would be different and would not be strictly in the same
place. The same structure would therefore be produced although
the individual behaviour of the bathers would be different.
According to Weiss, this is a phenomenon of self-organisation. It is
characterised by the emergence of a type of collective behaviour
