Causality, Complexity and Computers
H. r'ACSER, and J. A. BURNS
With 6 Figures
Abstract
Biological systems containing many components and complex interactions
between them require a different approach than is customary when dealing with
simpler situations. In particular, analytical procedures reveal mainly the structure
of the system. The behaviour of the system, however, is equally dependent on
the quantitative values of the parameters which may determine the type of response.
Experimental and theoretical questions must therefore take account of the system
as a whole. Some of the difficulties and possible solutions are discussed.
The problem of complexity has been facing biologists right from the
beginnings of the scientific studv of their subject. The recent advances in the
understanding of some of the molecular mechanisms operating,in organisms
has, in some circles, tended to the view that we are nearing a solution. It is
our view that, on the contrary, a close examination has revealed far greater
complexity than was evident before. More importantly, it has become clear
that a new methodological and conceptual approach is necessary if we are
to make progress hevond the mere cataloguing of an even greater number of
hiochemical details.
Structure and Quantity
To explain the difficulties which we have in relating the properties of an
organism to its fundamental biochemical events it is instructive to analyse
very briefly how we proceed in our studies. We can resolve our activities
broadly into a series of steps. The first step is essentially analytical. It
consists of the specification and sometimes the 'discovery' of the elements
in terms of which the investigation is to proceed. Thus, the anatomist
'dissects' the organism into organs, the physiologist into tissues, the
geneticist into characters, the chemist into molecules. Naturally there is
considerahle overlap between the fields but each field, or perhaps more
accurateh, each investigator, deals with a chosen set of elements which he
considers appropriate.
The specification of the elements is followed by and often closely
linked up with the establishment of the relations between them. The
establishment of which elements are coupled to each other and what the
H. r'ACSER, and J. A. BURNS
With 6 Figures
Abstract
Biological systems containing many components and complex interactions
between them require a different approach than is customary when dealing with
simpler situations. In particular, analytical procedures reveal mainly the structure
of the system. The behaviour of the system, however, is equally dependent on
the quantitative values of the parameters which may determine the type of response.
Experimental and theoretical questions must therefore take account of the system
as a whole. Some of the difficulties and possible solutions are discussed.
The problem of complexity has been facing biologists right from the
beginnings of the scientific studv of their subject. The recent advances in the
understanding of some of the molecular mechanisms operating,in organisms
has, in some circles, tended to the view that we are nearing a solution. It is
our view that, on the contrary, a close examination has revealed far greater
complexity than was evident before. More importantly, it has become clear
that a new methodological and conceptual approach is necessary if we are
to make progress hevond the mere cataloguing of an even greater number of
hiochemical details.
Structure and Quantity
To explain the difficulties which we have in relating the properties of an
organism to its fundamental biochemical events it is instructive to analyse
very briefly how we proceed in our studies. We can resolve our activities
broadly into a series of steps. The first step is essentially analytical. It
consists of the specification and sometimes the 'discovery' of the elements
in terms of which the investigation is to proceed. Thus, the anatomist
'dissects' the organism into organs, the physiologist into tissues, the
geneticist into characters, the chemist into molecules. Naturally there is
considerahle overlap between the fields but each field, or perhaps more
accurateh, each investigator, deals with a chosen set of elements which he
considers appropriate.
The specification of the elements is followed by and often closely
linked up with the establishment of the relations between them. The
establishment of which elements are coupled to each other and what the