Acid) copies segments of the
DNA; that is, it makes a copy of the base pair sequences through a process
called transcription. This messenger RNA then physically conveys this
template from a cell nucleus to cellular structures called ribosomes. Ribosomes
attach to the end of the messenger RNA molecule and travel down the template,
translating the information encoded in its base sequence and incorporating
specified amino acids into a growing protein molecule. Multiple ribosomes will
attach to a single messenger RNA molecule, simultaneously translating the
information contained in the template into multiple growing protein molecules,
all of which have an identical amino acid sequence that defines its form and
function. The ultimate result is the physical construction of cell components
according to the DNA blueprint.
Our
consideration of the DNA replication process is not nearly of sufficient detail
to provide a significant insight into the molecular chemistry involved; and,
that is not our intent. Rather, what is interesting is how modifications to
just the right molecules at just the right times within the replication process
can have pronounced effects on the resultant, replicated DNA. A change in a
single base pair can perhaps have an effect in the cell construction and
operation that derives from the DNA. More likely, however, such a change will
be compensated for by the fact that only relatively small sections of the DNA
are actually utilized for these processes in a typical cell. That is, within
the cell the higher probability is that a random DNA change will impact a
neutral segment of the DNA molecule. However, if for example the change results
in a modification of the attachment point for the protein molecule that
delimits a section of the DNA being replicated, then the resultant DNA contains
a much more significant change.
The individual
members of Homo sapiens sapiens emerge from a single cell; the result of
the initial conception of the individual. Historically, there have been
at least two central questions that revolve around this point; one
philosophical and one technical. The philosophical question is, “Does a person
come into being at the point of conception, or does the person emerge at some
later point in the development process?” Fully understanding the metaphorical
reference to person is obviously central to answering this question. This is,
of course, a central point of intersection and conflict among social systems
today. While we might contribute some technical information around the edges,
we are certainly unable to offer an answer to this question. The second
question is related, but can be couched as a technical rather than
philosophical consideration. Specifically, “Is the entity that derives from
conception complete from the point of conception, or is there a development
process that essentially builds up a new, complete human over time?” This
latter concept was given the designation of epigenesis and more
accurately reflects the biological development process of a person. The result
is the specialization of cells to form the many constituent components of a
living organism and to facilitate the special services provided by these
various components; germ cells, then specialized differentiated cells, then
organs and then the complete organism.
Our extremely
elementary rendition of how DNA replicates and guides the specialization of
form and function of cells is aimed at a couple of basic points. First, at its
most basic, life appears to be about mass. To replicate or reproduce is to
increase the mass of comparable life; this defines good within the
policy process evoked by the basic physical processes of life. Failure to reproduce
does not increase mass and, in the extreme results in the total absence of comparable
life. This defines bad. The terms good and bad apply an
anthropomorphic and more specifically moral view to essentially
mechanical and chemical functions, but they at least give us a sense of
direction in the consideration of evolutionary mechanisms. They provide the
guidelines and goalposts of a process called natural selection. If sufficient new constituent components are
available, if sufficient energy is available to drive the alignment and
recombination mechanisms and if the processes themselves are allowed to proceed
unhindered, then life continues. If either sufficient energy or new
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