Cybernatic cloning - a new approach
In biological research
by DEBRUP SENGUPTA
Indian Institute of Science
Bangalore - 560 012
During
the last decade biological science has been going through a
transition phase. Scientists have been able to amass a great
deal of knowledge, it may be in form of various genome projects
or may be in form of protein database or by understanding various
dynamic physiological processes. Inspite of this increase in
information regarding various biological phenomena in logarithmic
scale, there lies a very fundamental question that remains to
be answered: what are the basic principles or rules that can
be generalized for all life forms? To put this in a different
way, what are the principles that define life or a principle
that unifies all biological phenomena? As man's knowledge has
evolved, definition of life has changed from time to time.
Presently different people define life, based on different phenomena
like reproduction, respiration, and digestion. These definitions
give some generalization about life; they do not give anything
concrete to work upon. The basic problem encountered in formulating
such principle is, lack of different type of life form. If
there would had been a parallel evolution on earth itself or
on any other planet in close proximity, this may have generated
two distinct life forms, say carbon based life and silicon based
life. Different life forms would have helped in formulating
generalized principles of life. In order to formulate such
generalized principle of life, attempts are being made to design
artificial life form or system that could mimic the functional
scheme of any biological phenomena; one approach that is being
worked out in order to design such a model is based on the principle
of cybernetics. Cybernetic approach redefines life on the basis
of the vastness of controls operating in living system and the
information flow that brings about this control.
Cybernetics
is classically defined as the study of basic principles of "control"
that takes place in any type of dynamic process: machine, computer,
biological system, economics. Cybernetics gives mathematical
and logical interpretation of any control system, controlling
the dynamic process. Computer scientists and engineers have
always aspired to design better control system having high level
of automation. In order to design such system engineers turned
their attention toward biological controls and designed models
that mimicked these controls operating in biological system.
Designing of any control system is based on logical interpretation
and analysis of control flow, that is flow of information through
various components of control system. The trajectory that the
information takes is termed as loops. Mimicking this information
flow plays an important role in reducing the error, where the
error is the difference in the desired output and output that
is actually obtained during any dynamic process.
In
order to design cybernetic model of life, we have to interpret
life based on a principles of cybernetics. In order to do so,
we have to take different perspectives of living forms. First
of all we have to remember that any living system is an open
system, meaning that there is a continuous exchange of matter
and energy between the system and the surrounding. As there
exists continuous variation in the surrounding of a living system
with time and space, uncontrolled exchange of matter and energy
can take place along the potential gradient. Such uncontrolled
exchange may lead to thermodynamic disturbances. As a result,
system shifts to a state of increased entropy or randomness.
As per the information entropy equivalence theory, the sum of
information and entropy is always constant. For example, if
there are number of different nucleotides in a solution, then
the system has high entropy, but when they are arranged as polynucleotide
sequence, then they have less entropy, but high level of information.
This brings us to a conclusion that controls are needed in a
biological system to maintain a high information content. Whenever
we talk of control, then certain desired output for any given
phenomenon has to be defined and criteria have to be laid down
that define error. Nature sets the criteria for error in the
controls operating in biological system. Any biological unit
that shows large error has been removed during the course of
evolution through natural selection. To simplify the idea of
control and information flow, it can be stated that control
systems in biological systems are needed for proper transfer
of information: on the other hand, transfer of information is
needed for proper control. Above discussion gives a logical
justification of cybernetic approach to life, based on the notion
that vast number of controls and enormous amount of information
transfer is a ubiquitous phenomenon in the living world, and
this may form the basis of redefining life.
Going
by the principle of cybernetics, if any two operations or dynamic
processes show similar functional scheme, they are regarded
as cybernetic model of each other. A cybernetic model may not
necessarily be a well defined object: abstract phenomenon with
identical functional scheme like mathematical expression, can
act as cybernetic model. Designing cybernetic model for a biological
phenomenon involves deriving mathematical operation and logical
interpretation of the controls operating in the phenomenon,
and secondly mimicking the information flow that takes place
in the regulation of the phenomenon. To illustrate the above
approach let us consider a particular cell in a group of cells
under consideration. If we desire to interpret a particular
phenomenon in the cell of our interest by applying the principles
of cybernetics, we need to derive a mathematical relationship
of the phenomenon based on the transformation that it brings
about in the cell. Let a biological parameter that is being
transformed during the phenomenon ‘x’ be ‘y’. The quantity of
y in a given cell will then depend on intracellular status of
the cell itself at the very moment in time as well as the intracellular
status of neighbouring cells in the previous instant of time.
To obtain mathematical interpretation of the above phenomenon,
y could be defined by a function of x in the cell itself at
the very instant of time t and a function of x in adjacent cell
in previous instant of time (t-1)
The
mathematical function which we get
Y = ft (x) + g(t-1) (x)
Ft (x) Þ cell
itself
g(t-1) (x) Þ adjacent
cell
The
operations f and g determine the ways the two cells depend on
each other: rather it could be considered as the information
flow between the cells. Using this mathematical interpretation
and information pathway, an algorithm could be formulated.
This algorithm could be used to simulate the functional scheme
of biological phenomenon. Such cybernetic embodiment of biological
phenomenon could be regarded as different life form, showing
functional scheme of a life process or it can be regarded as
cybernetic clone of particular biological process.
This
approach may help to formulate general principles of life.
Such principle can play a significant role in laying down the
basis for theoretical biology. Cybernetic approach can give
a means of studying those biological phenomena for which, till
date no proper approach has been devised, for example, information
processing in brain. This may also help in reducing animal
experimentation and may give a preliminary idea of the phenomenon
under study. For example, if vaccine has to be developed using
a particular antigen, mathematical models of immune system which
has been derived to certain extent is used to get an idea about
clonal proliferation and antibody production. This mathematical
data can give a preliminary idea about the response of an immune
system towards any particular antigen under study.
However,
there are number of hurdles in the process of designing such
cybernetic models for biological phenomenon. To design such
model it is needed to understand the actual biological phenomenon
completely. As far as biological controls are concerned, the
interrelationship between the controls are so enormous that
understanding them and then obtaining their accurate model is
difficult. In order to formulate such approach it is needed
that biologists, computer scientists and mathematicians come
to a common platform. Let us imagine that this century witnesses
scientists from different domains of science like physics, mathematics,
computer, will pour in the knowledge of their respective fields
to unravel the mysteries of life lying inside our body. Our
salute is due to such awesome interdisciplinary effort of the
scientists of today and tomorrow.