| |
 hy
are we concerned about human cloning and stem cell research?
First, without wanting to be guilty of exaggeration, we believe
the human race has faced few decisions of greater significance
than how we will choose to address the issues surrounding human
cloning. One the one hand, the research community has in effect
said, “Stop us if you can!” On the other hand, the
breakthroughs in cloning technology have been so rapid and the
“advertised” potential benefits of stem cell research
so mind boggling that it has left many struggling to understand
the issues. Few if any issues highlight the fundamental frailty
of humanity more strikingly than the facts and implications
of human cloning and stem cell research. Although the biochemical
techniques may be sophisticated, the moral choices that have
to be made are clear, and the associated details are within
the grasp of our society and, perhaps most importantly, our
current generation of young people. In addition, because the
issues under consideration are moral and ethical, they are an
inescapable part of the Christian’s walk before God. For
both of these reasons, we believe the Christian community needs
to be informed so that they can be “salt” and “light”
wherever we live.
What’s a Stem Cell?
Before the issues surrounding human cloning and embryonic stem
cell research can be discussed and then evaluated from a Biblical
perspective, it is necessary to arrive at an understanding of
the science involved. The journey begins with the miracle of
development and the fact that all of the marvelous complexities
seen in living organisms originate with a single cell. This
unicellular beginning is the result of a merger between two
cells, a maternal egg and a paternal sperm. Individually, neither
egg nor sperm can lead to life, in that as haploid germ tissue,
they are reproductive cells containing only half the number
of chromosomes necessary for a new organism. The rest of the
cells in the body are known as diploid somatic tissue, referring
to the fact that they are non-reproductive tissues containing
the full number of chromosomes, half contributed from the maternal
line and half from the paternal line. In humans, the diploid,
or complete, state refers to a cell containing 46 chromosomes—so
then it follows, that the haploid egg and sperm each contain
23 chromosomes. (The statements of this paper apply specifically
to higher mammalian biology. Stem cell and cloning issues are
directly related to human beings, and associated research species,
and thus will be discussed in this context).
Once
an egg has been fertilized by a sperm, it contains the complete
genetic blueprint for a unique organism. This newly diploid
cell is now known as a zygote and is in the first stages of
the irreversible and complex process of embryogenesis. The first
developmental step is known as cleavage and is marked by a rapid
series of cell divisions creating a ball of cells known as a
morula. Approximately four days post-fertilization, the morula
develops further into a blastocyst, a structure composed of
two defined regions. The first is an outer cell mass, or trophoblast,
that will eventually become the chorion, a part of the placenta.
The second region lies within the trophoblast and is known as
the inner cell mass. It is this inner cell mass that becomes
the developing embryo. Approximately twelve days post-fertilization
the inner cell mass of the blastocyst begins to transform again,
into a state known as the gastrula. Gastrulation leads to three
identifiable tissues: the mesoderm, endoderm, and ectoderm,
which are the precursors of all adult tissues. Development continues
from this point as tissue and organ systems begin to take shape.
|
|
