Nothing really prepared the world for the 1997 announcement
that a group of Scottish scientists had created a cloned
sheep named Dolly. There's little doubt that within the
next decade, we will hear a more shocking announcement of the
first cloned human. Several groups have developed plans to be
the first to do so, and the research is already underway to
make it happen.
Talking to yourself will take on a whole new
meaning when cloning is made
possible.
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Until now, the idea of human cloning has only been possible
through movie magic, but the natural progression of science is
making human cloning a true possibility. We've cloned sheep,
mice and cows, so what's to stop scientists from cloning a
human? Some countries have set up laws banning cloning, but it
is still legal in many countries. It will cost tens of
thousands to hundreds of thousands of dollars, but there will
always be people willing to spend that type of money to be a
part of history.
Critics, backed by studies, say cloning is still a
dangerous technology that can cause serious defects in the
clones. The low success rates of cloning efforts of about 3
percent has also raised questions about the morality of
cloning a human. In this edition of How
Stuff WILL Work, we will look at the process that
could be used to clone humans, why we would want to clone
ourselves and the controversy surrounding cloning.
Me, Myself and My Clone
In January 2001, a
small consortium of scientists led by Panayiotis Zavos,
a former University of Kentucky professor, and Italian
researcher Severino Antinori said that they planned
to clone a human in the next two years. At about the same
time, the New
York Post reported a story about an American couple who
planned to pay $500,000 to Las Vegas-based Clonaid
for a clone of their deceased infant daughter.
These scientists may be chasing glory in the name of
science. Whatever their motivation, it's likely that we will
see the first cloned human baby appear on the evening news
perhaps as soon as 2005. Scientists have shown that current
cloning techniques work, but only rarely do they succeed in
creating a cloned embryo that makes it through birth.
If human cloning proceeds, scientists plan to use
somatic cell nuclear transfer, which is the same
procedure that was used to create Dolly the sheep. Somatic
cell nuclear transfer begins when doctors take the egg from a
donor and remove the nucleus of the egg, creating an
enucleated egg. A cell, which
contains DNA, is then taken from the person who is being
cloned. The enucleated egg is then fused together with the
cloning subject's cell using electricity. This creates an
embryo, which is implanted into a surrogate mother through
in vitro fertilization. If the procedure is successful,
then the surrogate mother will give birth to a baby that is a
clone of the cloning subject at the end of a normal gestation
period. Of course, the success rate is only about one or two
out of 100 embryos. It took 277 attempts to create Dolly. Take
a look at the graphic below to see how the somatic cell
nuclear transfer cloning process works.
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Some scientists seem to think that human cloning is
inevitable, but why would we want to clone people? There are
many reasons that would make people turn to cloning. Let's
explore a few of these reasons.
Who Will Clone?
Not all cloning would
involve creating an entirely new human being. Cloning is seen
as a possible way to aid some people who have severe
medical problems. One potential use of cloning technology
would involve creating a human repair kit. In other
words, scientists could clone our cells and fix mutated genes
that cause diseases. In January 2001, the British government
passed rules to allow cloning of human embryos to combat
diseases such as Parkinson's and Alzheimer's.
While it may take time for cloning to be fully accepted,
therapeutic cloning will likely be the first step in
that direction. Therapeutic cloning is the process by which a
person's DNA is used to grow an embryonic clone. However,
instead of inserting this embryo into a surrogate mother, its
cells are used to grow stem
cells. These stem cells can be used as a human repair kit.
They can grow replacement organs, such as hearts,
livers and skin. They can also be used to grow neurons to cure
those who suffer from Alzheimer's, Parkinson's or Rett
Syndrome.
Here's how therapeutic cloning works:
- DNA is extracted from a sick person.
- The DNA is then inserted into an enucleated donor egg.
- The egg then divides like a typical fertilized egg and
forms an embryo.
- Stem cells are removed from the embryo.
- Any kind of tissue or organ can be grown from these stem
cells to treat the sick.
Others see cloning as a way to aid couples with
infertility problems, but who want a child with at
least one of the parent's biological attributes. Zavos and
Antinori say that helping these couples is the goal of their
research. Zavos said that there are hundreds of couples
already lined to to pay approximately $50,000 for the service.
The group said that the procedure would involve injecting
cells from an infertile male into an egg, which would be
inserted into the female's uterus. Their child would look the
same as the father.
Another use for human cloning could be to bring deceased
relatives back to life. Imagine using a piece of your
great-grandmother's DNA to create a clone of her. In a sense,
you could be the parent of your great-grandmother. This opens
the door to many ethical problems, but it's a door that could
soon be opened. One American couple, who has had difficulty
dealing with the death of their infant daughter, is paying
$500,000 to Clonaid to clone their daughter using preserved
skin cells.
To Clone or Not to Clone
Critics of cloning
repeat the question often associated with controversial
science: "Just because we can, does it mean we should?" The
closer we come to being able to clone a human, the hotter the
debate over it grows. For all the good things cloning may
accomplish, opponents say that it will do just as much harm.
Another question is how to regulate cloning procedures.
There is no federal law banning cloning in the United
States, but several states have passed their own laws to ban
the practice. The U.S.
Food and Drug Administration (FDA) has also said that
anyone in the United States attempting human cloning must
first get its permission. In Japan, human cloning is a crime
that is punishable by up to 10 years in prison. England has
allowed cloning human embryos, but is working to pass
legislation to stop total human cloning.
While laws are one deterrent to pursuing human cloning at
this time, some scientists believe the technology is not ready
to be tested on humans. Ian Wilmut, one of co-creators
of Dolly, has even said that human cloning projects would be
criminally irresponsible. Cloning technology is still in its
early stages, and nearly 98 percent of cloning efforts end in
failure. The embryos are either not suitable for implanting
into the uterus or they die sometime during gestation or
shortly after birth.
Those clones that do survive wind up suffering from fatal
or problematic genetic abnormalities. Some clones have been
born with defective hearts, lung problems, diabetes, blood
vessel problems and malfunctioning immune systems. One of the
more famous cases was a cloned sheep that was born but
suffered from chronic hyperventilation caused by malformed
arteries leading to the lungs.
Opponents of cloning will point out that we can euthanize
these defective clones of other animals, but they ask what
happens if a human clone is born with these same problems.
Advocates of cloning respond that it is now easier to pick out
defective embryos even before they are implanted into the
mother. The debate over human cloning is just beginning, but
as science advances, it could be the biggest ethical dilemma
of the 21st century.
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