Biology Reference
In-Depth Information
since there are social groups which are not human (insects, pri-
mates etc.). From the moment we recognise the human level,
social groups can no longer be placed above it. If we place them
below it, that means that the human emerged from a property
common to all social groups (ants and primates for example). On
the other hand, owing to their composition or properties, many
organisms cannot occupy a sole level. Mammals are composed of
cells and circulating molecules. They therefore arise from both
these levels. Above which of them should we place mammals in
the hierarchy? The blood system is a collection of cells and circu-
lating molecules that ensure immune, nutritive, endocrine or
respiratory functions. Should it be considered as cells, tissues, an
organ, or as several organs? What about viruses? Are they living
or non-living beings? Where should they be classified? Syncitia
are multinucleated cells arising from the fusion of several cells:
should they be put with cells or with multicellular organisms?
Certain inanimate objects such as computers and robots are capa-
ble of remembering and calculating, even of demonstrating intel-
ligence, characteristics which are usually considered as indicating
a brain. Where are they to be placed in the layered model? These
examples are only a minute sample from the multitude of prob-
lems that are encountered when the layered model is confronted
with concrete cases. They just go on to show that we can legiti-
mately doubt the ontological reality of the layered model. Far from
representing the intrinsic organisation of the world, its different
variants seem rather to indicate a mode of subjectively dividing
up reality depending on the observer. Noble arrived at a very sim-
ilar conclusion from his work on cardiac physiology, and has put
forward what he calls a theory of biological relativity. Without
formally denying the existence of levels of organisation, he thinks
that none of them has any privileged causal role. They can all be
used as a starting point for analysing the living organism (Noble,
2006, 2008), which suggests that they are of epistemological rather
than ontological value.
