The Questions of Developmental Biology

federal proscription of human cloning. Some of the reasons cited by scientists and ethicists
against Robertson's human cloning arguments are:
1. Cloning is not a good technique for giving couples a chance to have genetically related
children,* for scientific reasons that include the following: (a) The resulting child would be
genetically related to only one member of the couple (which could cause enormous problems with
divorce and custody laws). (b) With a success rate so far from 100%, a woman could not produce
enough oocytes for the procedure to have a good chance of success. (c) This high failure rate
predicts that many cloned fetuses would abort or be born malformed. As Marie DiBerardino and
Robert McKinnell, two of the pioneers of cloning, have pointed out, "In nearly 100% of the cases,
[human cloning] would give rise to abnormal embryos and fetuses, almost all of which would
abort. And what an atrocity if an abnormal child were born!" (DiBerardino and McKinnell 1997).
2. Moral issues loom tremendous against the "spare parts" argument. A person cannot "own"
another person; a clone might not wish to be used for spare parts. Scenarios that involve the
creation of "brain-dead" clones kept "in storage" for spare parts are not acceptable to most of us
(see Krauthammer 1998). In addition, using cloning in this manner would extend the already
great social inequalities caused by differential access to medical care. Those with enough
resources could use cloned body parts to extend their lives to an unprecedented duration, creating
a situation wherein economic advantage becomes an overwhelming biological advantage.
3. No one knows the community or personal harm in being raised by a genetically identical
parent. Genetic uniqueness has always been assumed. (Or, as one student remarked, it's bad
enough being told what to do by a regular parent.)
4. Biologically speaking, clones are not "late-born twins." First, they fail the genetic definition of
identical twins, since their mitochondrial genes (derived from the eggs of different women) would
be different. Second, they fail the embryological criteria for twins in that they are not derived
from the same zygote and do not share the same uterus.
5. The government already sets limits on procreation rights. (You cannot legally marry your
sibling or your child, for instance.) It does so by consent of the government. A ban on human
cloning would not be a new role for the government.
The Society for Developmental Biology and other scientific societies have taken the stand that
researchers should be allowed to study the early human embryo in attempts to understand
diseases and development and to enhance fertility. They also do not wish to block pharmaceutical
companies from developing their products. However, these groups feel that we are not technically
or morally prepared to start cloning human beings.
*In earlier times, adoption of a niece or nephew was a fairly common means of raising a genetically related child. K. E.
von Baer, for instance, was raised by his childless aunt and uncle.
The Exception to the Rule: Immunoglobulin Genes
While the rule is that the genome is the same in every cell in the body, some white blood
cells that function as part of the immune system provide exceptions to that rule. The B
lymphocyte ("B cell") is able to synthesize proteins called immunoglobulins that can function as
antibodies. For decades, immunologists puzzled over how the immune system could possibly
generate so many different types of antibodies. Could all the 10 7 different types of antibody
proteins be encoded in the genome?