It's a strong possibility. Some scientists are convinced that the
developments in DNA technology that are already being used in animals
will, in time, be applied to humans. Parents could then pick and choose
their children's genes to guarantee they grow up to be unusually healthy,
or maybe just better looking and more intelligent than mum or dad.
If scientists discover which genes are responsible for these characteristics
and others such as sporting ability or musical talent, all will go
on the menu. Parents will be able to have their very own 'designer'
It's already possible to use genetic testing on very early embryos
to help a sick person. A child may have leukaemia - a serious disease
that can be cured by a bone-marrow transplant - but no donor is available.
The parents may fertilise several eggs outside the body, test to see
which embryo carries the right genes to help its sibling, and then
implant only the one that does. This has already happened, more than
once. Parents may want to go one step beyond and use the same technique
to choose an embryo with desirable characteristics such as hair colour
or intelligence. Once the genes responsible for these things are known,
it will be scientifically possible. But do you think techniques like
this should be allowed?
In animals such as mice, it's been possible for quite some time to
inject extra genes into a one-cell embryo. If fact, in many labs it
is almost routine. But it's not an easy technique: only a small percentage
of the attempts actually succeed, and the inserted gene can mess up
other genes by not landing in the right place. To use this technique
in humans would be too risky.
Mouse scientists have another more efficient way of re-engineering
the embryo. It is a targeted 'cut and paste' approach in which the
original gene is replaced by an upgraded one. Others envisage using
artificial chromosomes that could be engineered with desirable genes
and inserted into the early embryo with few drawbacks.
Eventually the technology will be smoothed out, but even when it
is, should we use it? What concerns most scientists is that inserting
genes into the early embryo means changing genes in the sperm and
eggs which will then be passed on to the next generations. Some people
argue that tinkering with the human genome in this way, changing the
genes of our children, ought to be forbidden.
These are mind-boggling possibilities but they won't be happening
any time soon. We are far from understanding what determines most
human characteristics, let alone being able to engineer them into
cloning and genetic engineering
National Centre for Biotechnology
Two American scientists are already planning to do so. In October
2002, Dr Hamilton Smith, a Nobel prize-winning scientist, and Dr Craig
Venter, famous for sequencing the human
genome, said they could soon
have the ability to create a completely synthetic life form in the
Smith and Venter are proposing to create a very
simple microbe. But it won't be exactly from
scratch. They plan to strip down the genome of
the smallest existing bacterium - Mycoplasma
genitalium - synthesise a new set of genes, drop
them into the bug, and see if the new instructions
bring the bug to life. The scientists acknowledge
that trying to create a synthetic genome will
be intellectually challenging, but they are convinced
they will succeed. The work will be carried out
at the Institute of Biological Energy Alternatives
in Maryland, US.
Why do it? There are some very good reasons
for building artificial bugs. Smith's and Venter's
goal is to turn raw materials into hydrogen to
solve the world's energy problems. These tiny
microbes could also be given the right properties
to produce new drugs, new vaccines, even new
materials for industry. If they succeed, this
will bring extraordinary new possibilities for
scientists to alter and enhance the natural world,
together with difficult ethical security and
philosophical questions about the nature of life.
The risk, of course, is the unforeseen. Some
worry that something might escape from the lab
could cause havoc out in the real world. Others
think the technology might be stolen by terrorists
and used against us. These are valid fears. As
this project pushes ahead, we should get busy
making the rules and setting safeguards in place.
But the ultimate question will be: is it alive?
If that bug divides and copies itself, it's hard
to deny it's alive.
The Institute for Genomic
for Biological Energy Alternatives
One of the most exciting things about sequencing our genome is its
medical potential. We all want to live long, healthy lives, and understanding
how genes contribute to many common
diseases is likely to make this
wish come true.
Scientists are looking for small variations in our genome that can
make some of us more susceptible to common diseases. They are busy
collecting all the variant spellings of our genes in order to investigate
whether having a C instead of a G in a certain position, for example,
can make one person more likely to get an illness such as Alzheimer's
Disease or diabetes.
Once scientists discover which changes make a person more susceptible
to these diseases, people could be screened to find out whether they
are at risk. This would help because a person can make changes to
their lifestyle eating less sugar and taking more exercise, for example,
to avoid getting ill, or take preventative medicine.
Doctors will also use genetic screening to discover the best drug
for a patient. The fact about drugs is that they work well in some
people but not in others (for example, steroids help treat some people's
asthma but not everyone's) and some people experience side-effects.
How well you respond depends on your genetic predisposition. In the
future, a doctor may be able to screen a person's genes to find the
best drug treatment. People will no longer be prescribed drugs with
the 'one size fits all' approach we have at present, but instead,
each individual will receive the treatment that best fits their genetic
And as scientists understand more about the genome, and which proteins
a gene makes, drugs will become more powerful and more targeted. If,
for example, researchers find that a protein is missing in a certain
disease, a drug company can design a compound that mimics the supply;
if there is too much protein, they might find ways of switching off
the gene or blocking the receptor. With the new knowledge provided
by the sequence, we can expect more and better drugs to treat diseases
like Alzheimer's Disease and cancer for which, at present, there are
But the human genome will not have all the answers. There are environmental
factors, which are obviously important. Take schizophrenia - a mental
illness which makes people hear voices and suffer delusions. A person's
genetic make-up makes it more likely that they will develop the disease
but it's not the whole story. The environment is crucial. Researchers
know that things like recreational drugs and suffering a viral illness
as a foetus, can all trigger the problems. For most diseases, the
impact of the environment still needs to be clarified and this will
be a long, difficult job.
www.nature.com Nature Genetics
www.ornl.gov/hgmis/ Human Genome Project Information
No one doubts that hair and eye colour, or diseases like cystic fibrosis
are passed on through our genes. But what about our personality? Are
violent, aggressive people born that way? Is being gay or intelligent
in our genes? Nobody has the answers, although the human genome is
helping scientists ask more detailed questions about what is more
important: our genes or our experiences during childhood.
The classical way to study whether nature or nurture shape our personality
or behaviour is by studying twins. Since identical twins share all
their genes, the differences will be down to the environment. So far,
scientists have found that half of our personality traits, such as
neurotic behaviour or whether you are an introvert or an extrovert
are, hard-wired into our genes.
But behavioural geneticists are still finding it difficult to figure
out exactly which genes make you smart or slow, aggressive or laid
back. This is probably because it's not just one gene that turns you
into any of these things but a bunch of them. Scientists first have
to work out what these genes are, and then how they interact to make
us the way we are.
Yet of all the many thousands of genes in the human genome, the ones
involved in our personality and behaviour are the most controversial.
People fear that one day our genetic profile could reveal what sort
of person you are, even your tendency to behave in a certain way.
Many are anxious that genetic arguments might incite intolerance or
excuse criminal acts. But it's worth remembering that even though
genes play an important role in behaviour, we are much more than the
product of our genes. We will always need to look at the environment
to explain our behaviour.
Human Genome Project
http://www.kcl.ac.uk/depsta/law/research/cmle/ Centre of Medical Law and Ethics
The Institute of Psychiatry,
King's College, London
Stem cells are hailed by many scientists as the therapeutic tool
of the future. These cells could fix all sorts of health problems,
from curing brain diseases such as Parkinson's Disease to repairing
hearts and growing new teeth. A lot of hope is pinned on stem cells.
The power of stem cells lies in their potential to turn into a wide
variety of specialised cells. The embryo is full of stem cells, and
so is the umbilical cord of a new-born baby. Scientists isolate and
study them to work out what turns them into a particular type of cell,
be it a nerve cell, a muscle cell or a liver cell.
The aim is to cure different diseases by transplanting the right
kind of stem cell. For example, Parkinson's Disease is caused by a
lack of certain nerve cells in the brain, while diabetes is due to
a lack of specialised pancreatic cells. Clinical trials in patients
with Parkinson's Disease have already gone ahead and, although the
results are promising, there are still many technical wrinkles that
need to be ironed out.
Stem cells could also allow scientists to grow new organs for transplant.
This would be a great plus since thousands of people die each year
waiting for a donor. For it to be possible, scientists must first
understand and control the huge amount of signals that tell stem cells
to make specific tissues.
But there are those who object strongly to the use of stem cells
in medical research. The ethical dilemma revolves around the source
of stem cells. Some people argue that all research on stem cells is
unacceptable because they can only be harvested from embryos, which,
they claim, are potential human beings and therefore have the same
rights as human beings. Once again, as with much of genetic research,
there are no easy answers.
Nuffield Council on Bioethics