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Vol.
XXVII No. 25
June 22,
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Human Cloning A Distinct Possibility
Amit
Sen Gupta
RECENTLY, the
team that had cloned Dolly (the first large animal to be cloned) announced that
they are working on human cloning. A few months back, the whole world and
especially the scientific establishment was stunned by the claim of the first
succesful homan cloning in end December, last year.
The claim came from a rather obscure organisation called Clonaid.
Brigitte Boisselier, an industrial chemist, claimed on behalf of the
organisation that a thirty one year old American woman had given birth to the
first cloned human baby at a secret location outside the United States.
She refused to divulge any further details and only identified the baby as a
female by the name of Eve. The baby was claimed to be an exact replica of its
mother and formed by the fusion of genetic material taken from the mothers
skin cell and her ovum (egg cell). If true, that would make the baby her
mothers child as well as her twin!
Clonaid however
did promise that they would soon provide proof that such a cloned baby had
indeed been born. The announcement drew skepticism from a host of experts who
questioned whether Boisseliers company, Clonaid, has the know-how to pull off
the scientifically challenging feat. Within less than a week, however, with no
proof forthcoming, it started becoming clear that the announcement was actually
a gigantic and elaborate hoax.
Boisselier is a
leading member of the Raelian religion, which was formed by a French journalist
and race car driver, Claude Vorilhon, after he claimed to have been visited by
extraterrestrials in 1973. Clonaid was started in the Bahamas in 1997 after
Scottish scientists cloned Dolly the sheep. Its officials have declined to
disclose where its offices are located.
Clonaid claims
that they used knowledge that was supplied by space aliens. It is their belief
that the earth was colonised by humans who were clones left behind by
extraterrestrial beings who had visited the earth from a distant part of the
galaxy. They further claim that their plans are eventually to perpetuate
individuals by creating adult clones and downloading memories and personality
into the new, identical bodies. In other words create immortal beings whose
bodies are regularly replaced by clones. The idea sounds straight from a science
fiction novel, and has had scientists across the globe denouncing such claims as
figments of imagination.
Now it is clear
that the initial claim was actually a fraud. But through it, Brigitte Boisselier
(who is supposed to have led the team of scientists who performed the
feat) and Clonaid acquired near celebrity status as she flew across the
world and lectured about her feat. What this hoax has, however achieved,
is to focus once again on the debate on the ethics and utility of human cloning.
While Clonaids claim was obviously a hoax, it cannot be disputed that the
technology for human cloning, however imperfect, is already available. Let us
look at what human cloning really involves.
WHAT IS
CLONING?
Cloning is the
production of one or more individual plants or animals that are genetically
identical to another plant or animal. Nature itself is the greatest cloning
agent. In about one of every 75 human conceptions, the fertilized ovum splits
for some unknown reason and produces (identical) twins who have an identical
genetic make-up. Two very different procedures
have been
referred to as cloningembryo cloning and Adult DNA. cloning.
Embryo Cloning
might more accurately be called artificial twinning, because it simulates
the mechanism by which twins naturally develop. Cloning of embryos has been used
in animal breeding since the late 1980s, and in mice experiments since the late
1970s. The procedure split a single fertilized ovum into two or more clones,
each of which is then implanted into the wombs of receptive females. The methods
used have been understood for many years and actually used to clone embryos in
cattle and sheep.
Human embryo
cloning starts with a standard in vitro fertilization procedure — known in
common language as the test-tube baby technology. Sperm and an egg cell
are mixed together on a glass dish. After conception, the fertilized egg is
allowed to develop into a hollow mass of cells by dividing first into two cells,
then four, then eight, and so on. This mass of cell is divided into individual
cells which are deposited on individual dishes, where they are allowed to divide
and develop. After a stage each of these are implanted into the wombs of
separate females. Theoretically it is possible to obtain 32 separate cells from
a single fertilised egg by this technique. However this has never been tried and
laboratory experiments have dealt only with defective eggs and the process has
been aborted after a few days. But the experiments have established that this
manner of cloning is possible. A team of Australian doctors have admitted that
they accidentally used this process to actually produce twins while
producing a test-tube baby. Thus a kind of cloning technology has been known to
work for quite some time, though no one admits that it has been done
intentionally to produce separate individuals.
ADULT
DNA
CLONING
Cloning using
Adult DNA is more complex and involves
a larger number of ethical issues. In embryo cloning the resultant clones
have genetic material from both parents. In Adult DNA techniques, the
clones have genetic material from only one parent. This was assumed to be
impossible in all mammals, until it was achieved in
UK, by Dr Ian Wilmut of the Roslin Institute in Roslin, Scotland with the
successful production of Dolly in 1997. Dolly was the first large cloned animal
using DNA from another adult. Since
Dollys conception, the Institute has successfully cloned other sheeps of
different breeds. The technique that they developed can probably be applied to
other domesticated mammals and conceivably even to humans.
With the
exception of the sperm and egg, every cell in the body contains all the genetic material in its DNA to theoretically create an
exact clone of the original body. In Dollys case, a cell was taken from
breast tissue of a mature 6 year old sheep and fused with a sheep ovum (egg)
which had had its nucleus (with all the DNA material) removed. The
fertilized cell was then stimulated with an electric pulse. Out of 277
cell fusions, only 29 began to divide. These were all implanted in ewes. 13
became pregnant but only one lamb, Dolly, was born. It remains to be seen
whether Dolly is fertile. Some cloned frogs are infertile. Also, cells
seem to have an internal clock that causes them to die off after a normal life.
Since Dolly was conceived from a 6 year old cell, her life expectancy may be
reduced. But the important point is that once Dolly became a
possibility, human cloning was always on the cards.
While it is true
that failure rates were very high when trying to make Dolly, they will get
lower. And there might not be a shortage of human eggs to use for cloning in
future, if the ideas of the likes of Clonaid become a reality. In theory, it is
possible to harvest hundreds of thousands of eggs from a foetal ovary. In
cloning by DNA transfer technology, the egg does not provide any genetic
material and so the donor hardly matters.
Conceivably,
there would be no shortage of surrogate wombs, since clones are likely to be
carried by the women who want them
as their own children.
POTENTIAL USES
AND
ABUSES OF CLONING
Some scientists
believe that human embryo cloning and related research can have certain positive
results. It might produce greater understanding of the causes of miscarriages,
and might generate new, effective contraceptives that exhibit very few side
effects. Experience gained in cloning may add to our understanding of genetics
and lead to the creation of animals organs which have been genetically altered
so that they can be transplanted to
humans. The rapid growth of the human fertilised egg is similar to the rate at
which cancer cells propagate. Cancer researchers believe that if a method is
found to stop the division of a human ovum then a technique for terminating the
growth of cancerous cells might be found. Treatments for damage to the brain or
nervous system might be possible due to cloning.
Parents who are
known to be at risk of passing a genetic defect to a child could make use of
cloning. A fertilized ovum could be cloned, and the duplicate tested for
the disease or disorder. If the clone was free of genetic defects, then the
other clone would be as well. The latter could be implanted in the woman and
allowed to mature to term. In conventional in vitro fertilization, doctors
attempt to start with many ovums, fertilize each with sperm and implant all of
them in the womans womb in the hope that one will result in pregnancy. But
some women can only supply a single egg.
Through the use
of embryo cloning, that egg might be divisible into, say, 8 zygotes for
implanting. The chance of those women becoming pregnant more quickly would be
much greater. A couple in which the husband is completely sterile could use
adult DNA cloning to produce a child. An ovum from the woman would be coupled
with a cell from the mans bodyboth would thus contribute to the child.
At the same time
doubts have been expressed about the technology due to a number of potential
misuses. The genetic screening test described above could also be used to
eliminate zygotes of a particular gender, without requiring a later abortion
A country might finance a programme similar to that of Nazi Germany
whereby humans were bred to maximize certain traits.
Once the perfect human was developed, embryo cloning could be used
to replicate that individual and conceivably produce unlimited numbers of
clones. The same approach could be used to create a genetic underclass for
exploitation: e.g. individuals with sub-normal intelligence and above normal
strength.
Dolly was
conceived using an ewes egg and a cell from another ewes body. It is noteworthy that no semen from a ram was involved. If
the technique were perfected in humans, and came into general usage, then there
would be no genetic need for men. All of the human males could be allowed to die
off. Large scale cloning could
deplete genetic diversity. And it is diversity that drives evolution and
prevents an entire species from disappearing because of susceptibility to a
disease. Some people have expressed concern about the effects that cloning would
have on relationships. For example,
a child born of an adult DNA cloning from his father would be, in effect, a
delayed twin of one of his parents.
REDESIGNING
OUR FUTURE?
Cloning has
always caught the public imagination. We now have the technology to take a few
cells from a modern day Einstein, or a musical genius or a child prodigy and to
create hundreds of babies which have exactly the same genes. An
attractive proposition indeed for a powerful megalomaniac,
who fancies the idea of populating
the world with a new race of genetically superior people. But what people
fail to understand is that cloning will not produce identical individualsat
least not with the level of technology we have today. The individual clones
would all have different wombs to develop in and different environments in which
they would grow up in after birth. So even with the same genes, they would end
up with entirely different characteristics.
The lesson of
history is that whatever is possible will be tried somewhere by someone at some
timebut this is no excuse for sitting back. Those who split the atom were
excited about the immense potential of the process in providing an almost
unlimited energy source for mankind. They certainly did not bargain for the
nuclear holocaust at Hiroshima and the ensuing nuclear arms race. The choice is
ours. We cannot ignore gene technology, nor should we condemn all of it. But
if we do not control gene technology today, it may well redesign us by tomorrow.
