chshkt

Chances are, of course, that human enhancement will lead neither to
utopia nor to the end of humanity. More likely each new technology
will be debated, tested and, if useful and not directly harmful,
eventually assimilated into everyday life. Already there are people
among us who possess what once seemed like superpowers: vision more
acute than anything anyone was born with thanks to laser surgery,
superhuman powers of concentration or the ability to go for days
without sleep thanks to psychoactive drugs, and the ability to
perform astonishing feats of strength, speed and endurance thanks to
steroids.

Even technologies that seem morally questionable at first soon
become socially acceptable. In 1969, a poll found that a majority of
Americans believed that IVF "violated God's will"; by 1978 a
majority said they would use it. In the 1960s many US states
outlawed the contraceptive pill for fear that it would be too
socially disruptive; few would do the same now. Most experts agree
that human enhancement is coming, and that there is no off button
for what we have already started. But the outcome is not
predetermined. It's time to start choosing your future.

Towards immortality
Woody Allen once said: "I don't want to achieve immortality through
my work. I want to achieve it through not dying." It won't happen
for him, nor for anyone else alive today, but many researchers
believe that we are at the start of a revolution that could deliver
if not immortality, then something resembling it.

A century ago, life expectancy in the developed world was around 55
years. Today it is nudging 80. "We have made tremendous advances -
by accident," says Sarah Harper, director of the Oxford Institute of
Ageing at the University of Oxford. "We weren't actually planning to
extend lives."

That is all changing. Harper says there is now a widespread belief
that we can "effect radical change, extending both maximum lifespan
and normal healthy lifespan". It will be slow and painstaking, but
some gerontologists are willing to bet that there are people alive
today who will still be alive in 2150.

One of those is Aubrey de Grey, a theoretical gerontologist at the
University of Cambridge. He will tell anyone who is prepared to
listen that in 20 to 30 years it will be possible to deliver radical
increases in longevity, largely by repairing cellular and molecular
damage. "I think the first person to live to 1000 might be 60
already," he says.

Among gerontologists, De Grey is almost universally regarded as a
maverick and a nuisance, but even some of his fiercest critics agree
that it now appears possible to deliberately intervene to increase
longevity. Among them is Jay Olshansky of the University of Illinois
in Chicago, who with three colleagues recently called on the US
government to invest $3 billion a year into anti-ageing research
(The Scientist, vol 20, p 28). "The time has arrived to slow ageing
in humans," says Olshansky. His target: seven years.

HALVE YOUR RISK

Why seven? Olshansky says that the risk of death and age-related
diseases rises exponentially throughout your lifetime, starting at
puberty and with a doubling time of seven years. So if you could
delay ageing by seven years, you would halve everyone's risk of
dying at any given age. And when the end does come, he says, you
suffer a relatively short period of ill health and die quickly,
avoiding the nightmare scenario of a "nursing-home world" full of
decrepit old people.

Underpinning Olshansky's plan is animal research showing that mice
on severely calorie-restricted diets live around 40 per cent longer
than normal. They remain vigorous, healthy and alert deep into old
age, and then die quickly. According to Olshansky's colleague
Richard Miller of the University of Michigan in Ann Arbor, we now
know of 10 mutations in mice that accomplish the same effect as
caloric restriction, suggesting the possibility of anti-ageing drugs
that recreate these effects.

If the mouse results were translated into humans, Miller says, it
would mean a healthy lifespan of 112 years. "Learning how to do this
in humans would be a good idea," he says. Olshansky insists that
stopping or reversing ageing is not the issue. "We're not talking
about dramatic extension of life," he says. "The operative word is
delay. But if you want to achieve immortality, this is a good place
to start."

Designer children
In June 2003, Michelle Whitaker gave birth to a baby boy, James, in
a hospital in Sheffield, UK. During the birth doctors took a sample
of James's umbilical cord blood and banked it for later use. The
intended recipient wasn't James: it was his older brother Charlie,
who suffers from a rare form of anaemia and whose only hope of a
cure was an injection of tissue-matched stem cells.

James was a "designer baby", conceived by IVF and selected from
among many embryos to ensure that he would be a suitable donor for
Charlie, using a technology called pre-implantation genetic
diagnosis. PGD involves taking a single cell while the embryo is at
an early stage - just 4 to 10 cells - and scrutinising its genome.
It has been used thousands of times since its first success in 1990,
but the Whitakers' case broke new ground.

Until James, PGD had been almost exclusively used to reject embryos
carrying undesirable genes for diseases or disabilities including
Huntington's, cystic fibrosis, sickle cell anaemia and even a
predisposition to cancer. The Whitakers' case showed it can also be
used to positively select for desirable traits. And that, some
people believe, marks the beginning of a world where parents can
start to choose their children's genetic make-up.

SPECIFIC TRAITS

Of course, to select desirable traits you have to know which genes
you're looking for, and that is a big challenge. Even so, some
geneticists think it might soon be possible to specify relatively
uncomplicated traits such as height or leanness, and as our
understanding of the human genome improves, the possibilities are
going to expand.

Screening, however, is not the same as creating genuine designer
babies. To do that you would have to genetically engineer the
embryo. Some PGD researchers are already working on "embryo gene
therapy" to repair defective genes at a very early stage. Once you
can do that, it may be possible to alter perfectly healthy genes to
boost intelligence, height or other valued traits.

No one believes that will be easy, and many scientists think it is
unrealistic to expect anything like it. Traits such as intelligence
result from the interaction of hundreds, possibly thousands, of
genes, plus myriad environmental factors. Controlling the outcome
might prove to be nigh on impossible, as well as hugely expensive.
There are technical hurdles too, such as the need to create dozens
of embryos to have enough to screen. But as the President's Council
on Bioethics put it: "In this enormously fertile and rapidly
developing field, the future is unknowable... No one should
confidently bet against any form of scientific and technological
progress."

Smarter minds
In a lab at the University of Cambridge, Danielle Turner is turning
ordinary Joes into masterminds. She gets them to perform a test
called the one-touch Tower of London planning task, which measures
one aspect of intelligence (see Diagram). The harder the task, the
more mistakes her volunteers make, but when she gives them a dose of
the drug modafinil they suddenly find it easier. "You see quite a
dramatic improvement in their performance, particularly when the
problem gets more difficult," she says.

Modafinil was not developed to make people smarter. It is sold as a
prescription-only "wakefulness promoter" for people with narcolepsy
and other sleep disorders, but it has a remarkable effect on normal
cognition: it improves not only planning but also decision-making
and verbal and visual memory. This has made it the latest drug of
choice among people looking for a mental boost or competitive edge.

Barbara Sahakian, also at Cambridge, describes modafinil as
the "first true smart drug". It won't be the last. There are dozens
more "cognition enhancers" in the pipeline. Last year an expert
panel appointed by the UK government identified 15 molecular
pathways in the brain that are under active investigation as targets
for cognition enhancement. All are being developed to help people
with cognitive impairment such as memory loss due to Alzheimer's,
but many will turn out to have a positive effect on normal, healthy
brains, and end up being guzzled like coffee

__________________
Start An Online Business, FREE!