copyright 2004
From a systems view, the cell, the basic unit
of biological life, resembles a computer. This resemblance provides a possible
explanation for how life could have developed.
Any scientific theory to explain biological
life should begin with a systematic explanation of what biological life
is. The basic unit of biological life is the cell. Individual life forms
consist of one or more cells. In complex life forms a variety of different
cells operate in a coordinated fashion to maintain the functions of the
life form.
The cell itself is a system that receives inputs
and produces outputs. Individual cells may pass through certain cycles
such as changing shape, but during normal operation each cell remains the
same much like a mechanical device.
In its internal operation, the cell receives
an input, accesses its memory for the appropriate instruction, acts on
that instruction to produce an output and then looks for the next input.
Memory consists of chains of DNA molecules, or chromosomes, organized in
a series of links composed of two molecules each. The number of links required
for each instruction, or gene, varies.
The molecules that comprise each link consist
of one of two different sets of two bases each. Thus each link consists
of one set of bases(0) or the other(1) with one member of the set(0) or
the other(1) attached to a specified side. Biologists refer to the bases
by four letters, but from a logical viewpoint the arrangement of the bases
can be portrayed with zeros and ones.
Thus, the cell can be described as a biochemical
computer with molecular memory. Most people think of computers as electromechanical
devices. However, a computer is actually a logical device rather than a
physical one. Physically a computer may use vacuum tubes or integrated
circuits. It is the logical operation rather than the physical makeup that
makes a machine a computer.
The zeros and ones a computer uses may indicate
a switch being opened or closed or the presence or absence of a hole on
a punched card. The terms "zero" and "one" merely refer to a dichotomous
physical condition. The arrangement of molecules in the DNA molecule can
be portrayed as dichotomous conditions.
If the cell is a computer, then it is possible
to suggest a way in which the cell and biological life could develop. Modern
computers are so easy to use that most people don't bother to think about
what happens to make computers work.
Early computers didn't know what to do when
they were turned on except to read a punched card or maybe a piece of paper
tape. This card contained something called a bootstrap loader that contained
the necessary instructions to read the contents of the card into memory
and begin loading a more sophisticated loader.
Modern science indicates that viruses can exist
separately from biological organisms and may even arrive on earth via meteorites.
A virus can contain a form of bootstrap loader that allows it to load itself
into a cell's memory and cause the cell to begin executing the instructions
contained in the virus.
Each cell contains the necessary instructions
to build a new cell, usually by duplicating the cell. Thus the DNA in the
cell would seem to contain the necessary blueprint to make a cell. A virus
like molecule containing such a blueprint could build a cell and then begin
operating by incorporating viruses with other instructions. Complexity
would increase with the addition of more viruses.
The arrival of new viruses on a meteorite could
explain development of groups of new species in the past. Mutations cannot
provide an adequate explanation for many new species because a mutation
would add a new feature by changing an old one. The old feature would cease
to exist without the addition of new DNA.
Experiments involving artificial life demonstrate
the possibility this approach could establish life on earth or another
planet. Some experiments involving simple organisms have used random assignment
of instructions to various computer programs with some surviving and some
not.
Those computer "organisms" that receive a set of workable instructions survive. Early cells would have had to have a set of functional instructions to survive. Viruses could have provided such instructions to a cell computer.
You can donate money to me through PayPal.