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The Last Human
We are on the cusp of profound biological change, poised to transcend our current form and character on a journey to destinations of new imagination. The arrival of safe, reliable germline technology will signal the beginning of human self-design. Progressive self-transformation could change our descendants into something sufficiently different from our present selves to not be human in the sense we use the term now. But the ultimate question of our era is whether the cutting edge of life is destined to shift from its present biological substrate — the carbon and other organic materials of our flesh — to that of silicon and its ilk, as proposed by leading artificial-intelligence theorists such as Hans Moravec and Ray Kurzweil.
Originally published April
2002. Excerpt from Redesigning
Humans: Our Inevitable Genetic Future. Published on KurzweilAI.net
June 5, 2002.
God and Nature first made us what we are, and then out of our
own created genius we make ourselves what we want to be . .
.Let the sky and God be our limit and Eternity our measurement.
-Marcus Garvey (1887-1940)
We know that Homo sapiens is not the final word in primate evolution,
but few have yet grasped that we are on the cusp of profound biological
change, poised to transcend our current form and character on a
journey to destinations of new imagination.
At first glance, the very notion that we might become more than
"human" seems preposterous. After all, we are still biologically
identical in virtually every respect to our cave-dwelling ancestors.
But this lack of change is deceptive. Never before have we had the
power to manipulate human genetics to alter our biology in meaningful,
predictable ways.
Bioethicists and scientists alike worry about the consequences
of coming genetic technologies, but few have thought through the
larger implications of the wave of new developments arriving in
reproductive biology. Today in vitro fertilization is responsible
for fewer than 1 percent of births in the United States; embryo
selection numbers only in the hundreds of cases; cloning and human
genetic modification still lie ahead. But give these emerging technologies
a decade and they will be the cutting edge of human biological change.
These developments will write a new page in the history of life,
allowing us to seize control of our evolutionary future. Our coming
ability to choose our children's genes will have immense social
impact and raise difficult ethical dilemmas. Biological enhancement
will lead us into unexplored realms, eventually challenging our
basic ideas about what it means to be human.
Some imagine we will see the perils, come to our senses, and turn
away from such possibilities. But when we imagine Prometheus stealing
fire from the gods, we are not incredulous or shocked by his act.
It is too characteristically human. To forgo the powerful technologies
that genomics and molecular biology are bringing would be as out
of character for humanity as it would be to use them without concern
for the dangers they pose. We will do neither. The question is no
longer whether we will manipulate embryos, but when, where, and
how.
We have already felt the impact of previous advances in reproductive
technology. Without the broad access to birth control that we take
so for granted, the populations of Italy, Japan, and Germany would
not be shrinking; birth rates in the developing world would not
be falling. These are major shifts, yet unlike the public response
to today's high-tech developments, no impassioned voices protest
birth control as an immense and dangerous experiment with our genetic
future. Those opposing family planning seem more worried about the
immorality of recreational sex than about human evolution.
In this book, we will examine the emerging reproductive technologies
for selecting and altering human embryos. These developments, culminating
in germline engineering -- the manipulation of the genetics of egg
or sperm (our "germinal" cells) to modify future generations
-- will have large consequences. Already, procedures that influence
the germline are routine in labs working on fruit flies and mice,
and researchers have done early procedures on nonhuman primates.
Direct human germline manipulations may still be a decade or two
away, but methods of choosing specific genes in an embryo are in
use today to prevent disease, and sophisticated methods for making
broader choices are arriving every year, bringing with them a taste
of the ethical and social questions that will accompany comprehensive
germline engineering.
The arrival of safe, reliable germline technology will signal the
beginning of human self-design. We do not know where this development
will ultimately take us, but it will transform the evolutionary
process by drawing reproduction into a highly selective social process
that is far more rapid and effective at spreading successful genes
than traditional sexual competition and mate selection.
Human cloning has been a topic of passionate debate recently, but
germline engineering and embryo selection have implications that
are far more profound. When cloning becomes safe and reliable enough
to use in humans -- which is clearly not yet the case -- it will
be inherently conservative, if not extremely so. It will bring no
new genetic constitutions into being, but will create genetic copies
of people who already exist. The idea of a delayed identical twin
is strange and unfamiliar, but not earthshattering. Most of us have
met identical twins. They are very similar, yet different.
Dismissal of technology's role in humanity's genetic future is
common even among biologists who use advanced technologies in their
work. Perhaps the notion that we will control our evolutionary future
seems too audacious. Perhaps the idea that humans might one day
differ from us in fundamental ways is too disorienting. Most mass-media
science fiction doesn't challenge our thinking about this either.
One of the last major sci-fi movies of the second millennium was
The Phantom Menace, George Lucas's 1999 prequel to Star Wars. Its
vision of human biological enhancement was simple: there won't be
any. Lucas reveled in special effects and fantastical life forms,
but altered us not a jot. Despite reptilian sidekicks with pedestal
eyes and hard-bargaining insectoids that might have escaped from
a Raid commercial, the film's humans were no different from us.
With the right accent and a coat and tie, the leader of the Galactic
Republic might have been the president of France.
Such a vision of human continuity is reassuring. It lets us imagine
a future in which we feel at home. Space pods, holographic telephones,
laser pistols, and other amazing gadgets are enticing to many of
us, but pondering a time when humans no longer exist is another
story, one far too alien and unappealing to arouse our dramatic
sympathies. We've seen too many apocalyptic images of nuclear, biological,
and environmental disaster to think that the path to human extinction
could be anything but horrific.
Yet the road to our eventual disappearance might be paved not by
humanity's failure but by its success. Progressive self- transformation
could change our descendants into something sufficiently different
from our present selves to not be human in the sense we use the
term now. Such an occurrence would more aptly be termed a pseudoextinction,
since it would not end our lineage. Unlike the saber-toothed tiger
and other large mammals that left no descendants when our ancestors
drove them to extinction, Homo sapiens would spawn its own successors
by fast-forwarding its evolution.
Some disaster, of course, might derail our technological advance,
or our biology might prove too complex to rework. But our recent
deciphering of the human genome (the entirety of our genetic constitution)
and our massive push to unravel life's workings suggest that modification
of our biology is far nearer to reality than the distant space travel
we see in science fiction movies. Moreover, we are unlikely to achieve
the technology to flit around the galaxy without being able to breach
our own biology as well. The Human Genome Project is only a beginning.
Considering the barrage of press reports about the project, we
naturally wonder how much is hype. Extravagant metaphor has not
been lacking. We are deciphering the "code of codes,"
reading the book of life," looking at the "holy grail
of human biology." It is reminiscent of the enthusiasm that
attended Neil Armstrong's 1969 walk on the moon. Humanity seemed
poised to march toward the stars, but 2001 has come and gone, and
there has been no sentient computer like HAL, no odyssey to the
moons of Jupiter. Thirty years from now, however, I do not think
we will look back at the Human Genome Project with a similar wistful
disappointment. Unlike outer space, genetics is at our core, and
as we learn to manipulate it, we are learning to manipulate ourselves.
Well before this new millennium's close, we will almost certainly
change ourselves enough to become much more than simply human. In
this book, I will explore the nature and meaning of these coming
changes, place them within the larger context of our rapid progress
in biology and technology, and examine the social and ethical implications
of the first tentative steps we are now taking.
Many bioethicists do not share my perspective on where we are heading.
They imagine that our technology might become potent enough to alter
us, but that we will turn away from it and reject human enhancement.
But the reshaping of human genetics and biology does not hinge on
some cadre of demonic researchers hidden away in a lab in Argentina
trying to pick up where Hitler left off. The coming possibilities
will be the inadvertent spinoff of mainstream research that virtually
everyone supports. Infertility, for example, is a source of deep
pain for millions of couples. Researchers and clinicians working
on in vitro fertilization (IVF) don't think much about future human
evolution, but nonetheless are building a foundation of expertise
in conceiving, handling, testing, and implanting human embryos,
and this will one day be the basis for the manipulation of the human
species. Already, we are seeing attempts to apply this knowledge
in highly controversial ways: as premature as today's efforts to
clone humans may be, they would be the flimsiest of fantasies if
they could not draw on decades of work on human IVF.
Similarly, in early 2001 more than five hundred gene-therapy trials
were under way or in review throughout the world. The researchers
are trying to cure real people suffering from real diseases and
are no more interested in the future of human evolution than the
IVF researchers. But their progress toward inserting genes into
adult cells will be one more piece of the foundation for manipulating
human embryos.
Not everything that can be done should or will be done, of course,
but once a relatively inexpensive technology becomes feasible in
thousands of laboratories around the world and a sizable fraction
of the population sees it as beneficial, it will be used.
Erewhon, the brilliant 1872 satire by Samuel Butler, contains a
scene that suggests what would be needed to stop the coming reworking
of human biology. Erewhon is a civilized land with archaic machines,
the result of a civil war won by the "anti-machinists"
five centuries before the book's story takes place. After its victory,
this faction outlawed all further mechanical progress and destroyed
all improvements made in the previous three centuries. They felt
that to do otherwise would be suicide. "Reflect upon the extraordinary
advance which machines have made during the last few hundred years,"
wrote their ancient leader, "and note how slowly the animal
and vegetable kingdoms are advancing . . . I fear none of the existing
machines; what I fear is the extraordinary rapidity at which they
are becoming something very different to what they are at present
. . . Though our rebellion against their infant power will cause
infinite suffering . . . we must [otherwise see] ourselves gradually
superseded by our own creatures until we rank no higher in comparison
with them, than the beasts of the field with ourselves."
Butler would no doubt have chuckled at his own prescience had he
been able to watch the special-purpose IBM computer Deep Blue defeat
world chess champion Garry Kasparov in May 1997.We are at a similar
juncture with our early steps toward human genetic manipulation.
To "protect" ourselves from the future reworking of our
biology would require more than an occasional restriction; it would
demand a research blockade of molecular genetics or even a general
rollback of technology. That simply won't occur, barring global
bio- catastrophe and a bloody victory by today's bio-Luddites.
One irony of humanity's growing power to shape its own evolution
is the identity of the architects. In 1998, I spoke at a conference
on mammalian cloning in Washington, D.C., and met Ian Wilmut, the
Scottish scientist whose cloning of Dolly had created such a furor
the previous year. Affronted by my relative lack of concern about
the eventual cloning of humans, he vehemently insisted that the
idea was abhorrent and that I was irresponsible to say that it would
likely occur within a decade. His anger surprised me, considering
that I was only speaking about human cloning, whereas he had played
a role in the breakthrough that might bring it about. Incidentally,
patent attorneys at the Roslin Institute, where the work occurred,
and PPL Therapeutics, which funded the work, did not overlook the
importance of human applications, since claims on their patent specifically
cover them.
We cannot hold ourselves apart from the biological heritage that
has shaped us. What we learn from fruit flies, mice, or even a cute
Dorset ewe named Dolly is relevant to us. No matter how much the
scientists who perform basic research in animal genetics and reproduction
may sometimes deny it, their work is a critical part of the control
we will soon have over our biology. Our desire to apply the results
of animal research to human medicine, after all, is what drives
much of the funding of this work.
Over the past hundred years, the trajectory of the life sciences
traces a clear shift from description to understanding to manipulation.
At the close of the nineteenth century, describing new biological
attributes or species was still a good Ph.D. project for a student.
This changed during the twentieth century, and such observations
became largely a means for understanding the workings of biology.
That too is now changing, and in the first half of the twenty-first
century, biological understanding will likely become less an end
in itself than a means to manipulate biology. In one century, we
have moved from observing to understanding to engineering. Early
Tinkering The best gauge of how far we will go in manipulating our
genetics and that of our children is not what we say to pollsters,
but what we are doing in those areas in which we already can modify
our biology. On August 2, 1998, Marco Pantani cycled along the Champs
Élysées to win the eighty-fifth Tour de France, but
the race's real story was the scandal over performance enhancement
-- which, of course, means drugs.
The banned hormone erythropoietin was at the heart of this particular
chapter in the ongoing saga of athletic performance enhancement.
By raising the oxygen-carrying capacity of red blood cells, the
drug can boost endurance by 10 to 15 percent. Early in the race,
a stash of it was found in the car of the masseur of the Italian
team Festina -- one of the world's best -- and after an investigation
the entire team was booted from the race. A few days later, more
erythropoietin was found, this time in the possession of one of
the handlers of the Dutch team, and several of its cyclists were
kicked out. As police raids intensified, five Spanish teams and
an Italian one quit in protest, leaving only fourteen of the original
twenty-one teams.
The public had little sympathy for the cheaters, but a crowd of
angry Festina supporters protested that their riders had been unfairly
singled out, and the French minister of health insisted that doping
had been going on since racing began. Two years later in a courtroom
in Lille, the French sports icon Richard Virenque, five- time winner
of the King of the Mountains jersey in the Tour de France, seemed
to confirm as much when the president of the court asked him if
he took doping products. "We don't say doping," replied
Virenque. "We say we're 'preparing for the race.'"
The most obvious problem with today's performance-enhancing drugs
-- besides their being a way of cheating -- is that they're dangerous.
And when one athlete uses them, others must follow suit to stay
competitive. But more than safety is at issue. The concern is what
sports will be like when competitors need medical pit crews. As
difficult as the problem of doping is, it will soon worsen, because
such drugs will become safer, more effective, and harder to detect.
Professional sports offers a preview of the spread of enhancement
technology into other arenas. Sports may carry stronger incentives
to cheat, and thus push athletes toward greater health risks, but
the nonsporting world is not so different. A person working two
jobs feels under pressure to produce, and so does a student taking
a test or someone suffering the effects of growing old. When safe,
reliable metabolic and physiological enhancers exist, the public
will want them, even if they are illegal. To block their use will
be far more daunting than today's war on drugs. An antidrug commercial
proclaiming "Dope is for dopes!" or one showing a frying
egg with the caption "Your brain on drugs" would not persuade
anyone to stop using a safe memory enhancer.
Aesthetic surgery is another budding field for enhancement. When
we try to improve our appearance, the personal stakes are high because
our looks are always with us. Knowing that the photographs of beautiful
models in magazines are airbrushed does not make us any less self-conscious
if we believe we have a smile too gummy, skin too droopy, breasts
too small, a nose too big, a head too bald, or any other such "defects."
Surgery to correct these nonmedical problems has been growing rapidly
and spreading to an ever-younger clientele. Public approval of aesthetic
surgery has climbed some 50 percent in the past decade in the United
States. We may not be modifying our genes yet, but we are ever more
willing to resort to surgery to hold back the most obvious (and
superficial) manifestations of aging, or even simply to remodel
our bodies. Nor is this only for the wealthy. In 1994, when the
median income in the United States was around $38,000, two thirds
of the 400,000 aesthetic surgeries were performed on those with
a family income under $50,000, and health insurance rarely covered
the procedures. Older women who have subjected themselves to numerous
face-lifts but can no longer stave off the signs of aging are not
a rarity. But the tragedy is not so much that these women fight
so hard to deny the years of visible decline, but that their struggle
against life's natural ebb ultimately must fail. If such a decline
were not inevitable, many people would eagerly embrace pharmaceutical
or genetic interventions to retard aging.
The desire to triumph over our own mortality is an ancient dream,
but it hardly stands alone. Whether we look at today's manipulations
of our bodies by face-lifts, tattoos, pierced ears, or erythropoietin,
the same message rings loud and clear: if medicine one day enables
us to manipulate our biology in appealing ways, many of us will
do so -- even if the benefits are dubious and the risks not insignificant.
To most people, the earliest adopters of these technologies will
seem reckless or crazy, but are they so different from the daredevil
test pilots of jet aircraft in the 1950s? Virtually by definition,
early users believe that the possible gains from their bravado justify
the risks. Otherwise, they would wait for flawed procedures to be
discarded, for technical glitches to be worked through, for interventions
to become safer and more predictable.
In truth, as long as people compete with one another for money,
status, and mates, as long as they look for ways to display their
worth and uniqueness, they will look for an edge for themselves
and their children.
People will make mistakes with these biological manipulations.
People will abuse them. People will worry about them. But as much
could be said about any potent new development. No governmental
body will wave some legislative wand and make advanced genetic and
reproductive technologies go away, and we would be foolish to want
this. Our collective challenge is not to figure out how to block
these developments, but how best to realize their benefits while
minimizing our risks and safeguarding our rights and freedoms. This
will not be easy.
Our history is not a tale of self-restraint. Ten thousand years
ago, when humans first crossed the Bering Strait to enter the Americas,
they found huge herds of mammoths and other large mammals. In short
order, these Clovis peoples, named for the archaeological site in
New Mexico where their tools were first identified, used their skill
and weaponry to drive them to extinction. This was no aberration:
the arrival of humans in Australia, New Zealand, Madagascar, Hawaii,
and Easter Island brought the same slaughter of wildlife. We may
like to believe that primitive peoples lived in balance with nature,
but when they entered new lands, they reshaped them in profound,
often destructive ways. Jared Diamond, a professor of physiology
at the UCLA School of Medicine and an expert on how geography and
environment have affected human evolution, has tried to reconcile
this typical pattern with the rare instances in which destruction
did not occur. He writes that while "small, long- established
egalitarian societies can evolve conservationist practices, because
they've had plenty of time to get to know their local environment
and to perceive their own self-interest," these practices do
not occur when a people suddenly colonizes an unfamiliar environment
or acquires a potent new technology.
Our technology is evolving so rapidly that by the time we begin
to adjust to one development, another is already surpassing it.
The answer would seem to be to slow down and devise the best course
in advance, but that notion is a mirage. Change is accelerating,
not slowing, and even if we could agree on what to aim for, the
goal would probably be unrealistic. Complex changes are occurring
across too broad a front to chart a path. The future is too opaque
to foresee the eventual impacts of important new technologies, much
less whole bodies of knowledge like genomics (the study of genomes).
No one understood the powerful effects of the automobile or television
at its inception. Few appreciated that our use of antibiotics would
lead to widespread drug resistance or that improved nutrition and
public health in the developing world would help bring on a population
explosion. Our blindness about the consequences of new reproductive
technologies is nothing new, and we will not be able to erase the
uncertainty by convening an august panel to think through the issues.
No shortcut is possible. As always, we will have to earn our knowledge
by using the technology and learning from the problems that arise.
Given that some people will dabble in the new procedures as soon
as they become even remotely accessible, our safest path is to not
drive early explorations underground. What we learn about such technology
while it is imperfect and likely to be used by only a small number
of people may help us figure out how to manage it more wisely as
it matures. Genes and Dreams James Watson, codiscoverer of the structure
of DNA, cowinner of the Nobel Prize, and first director of the Human
Genome Project, is arguably the most famous biologist of our times.
The double-helical structure of DNA that he and Francis Crick described
in 1953 has become the universally recognized symbol of a scientific
dawn whose brightness we have barely begun to glimpse. In 1998,
I was the moderator of a panel on which he sat with a half-dozen
other leading molecular biologists, including Leroy Hood, the scientist
who developed the first automated DNA sequencer, and French Anderson,
the father of human gene therapy. The topic was human germline engineering,
and the audience numbered about a thousand, mostly nonscientists.
Anderson intoned about the moral distinction between human therapy
and enhancement and laid out a laundry list of constraints that
would have to be met before germline interventions would be acceptable.
The seventy-year-old Watson sat quietly, his thinly tufted head
lolled back as though he were asleep on a bus, but he was wide awake,
and later shot an oblique dig, complaining about "fundamentalists
from Tulsa, Oklahoma," which just happens to be where Anderson
grew up. Watson summed up his own view with inimitable bluntness:
"No one really has the guts to say it, but if we could make
better human beings by knowing how to add genes, why shouldn't we?"
Anderson, a wiry two-time national karate champion in the over-sixty
category, is unused to being attacked as a conservative. Too often
he has been the point man for gene therapy, receiving death threats
for his pioneering efforts in the early 1990s and for a more recent
attempt to win approval for fetal gene therapy. But the landscape
has shifted. When organizing this symposium, a colleague and I worried
about disruptive demonstrators, and could find only an occasional
article outside academia on human germline therapy. A year later,
stories about "designer children" were getting major play
in Time and Newsweek, and today I frequently receive e-mail from
high school students doing term papers on the subject.
Watson's simple question, "If we could make better humans
. . . why shouldn't we?" cuts to the heart of the controversy
about human genetic enhancement. Worries about the procedure's feasibility
or safety miss the point. No serious scientists advocate manipulating
human genetics until such interventions are safe and reliable.
Why all the fuss, then? Opinions may differ about what risks are
acceptable, but virtually every physician agrees that any procedure
needs to be safe, and that any potential benefit needs to be weighed
against the risks. Moreover, few prospective parents would seek
even a moderately risky genetic enhancement for their child unless
it was extremely beneficial, relatively safe, and unobtainable in
an easier way. Actually, some critics, like Leon Kass, a well-known
bioethicist at the University of Chicago who has long opposed such
potential interventions, aren't worried that this technology will
fail, but that it will succeed, and succeed gloriously.
Their nightmare is that safe, reliable genetic manipulations will
allow people to substantively enhance their biology. They believe
that the use -- and misuse -- of this power will tear the fabric
of our society. Such angst is particularly prevalent in western
Europe, where most governments take a more conservative stand on
the use of genetic technologies, even banning genetically altered
foods. Stefan Winter, a physician at the University of Bonn and
former vice president of the European Committee for Biomedical Ethics,
says, "We should never apply germline gene interventions to
human beings. The breeding of mankind would be a social nightmare
from which no one could escape."
Given Hitler's appalling foray into racial purification, European
sensitivities are understandable, but they miss the bigger picture.
The possibility of altering the genes of our prospective children
is not some isolated spinoff of molecular biology but an integral
part of the advancing technologies that culminate a century of progress
in the biological sciences. We have spent billions to unravel our
biology, not out of idle curiosity, but in the hope of bettering
our lives. We are not about to turn away from this.
The coming advances will challenge our fundamental notions about
the rhythms and meaning of life. Today, the "natural"
setting for the vast majority of humans, especially in the economically
developed world, bears no resemblance to the stomping grounds of
our primitive ancestors, and nothing suggests that we will be any
more hesitant about "improving" our own biology than we
were about "improving" our environment. The technological
powers we have hitherto used so effectively to remake our world
are now potent and precise enough for us to turn them on ourselves.
Breakthroughs in the matrixlike arrays called DNA chips, which may
soon read thirty thousand genes at a pop; in artificial chromosomes,
which now divide as stably as their naturally occurring cousins;
and in bio-informatics, the use of computer-driven methodologies
to decipher our genomes -- all are paving the way to human genetic
engineering and the beginnings of human biological design.
The birth of Dolly caused a stir not because of any real possibility
of swarms of replicated humans, but because of what it signified.
Anyone could see that one of the most intimate aspects of our lives
-- the passing of life from one generation to the next -- might
one day change beyond recognition. Suddenly the idea that we could
hold ourselves apart and remain who we are and as we are while transforming
the world around us seemed untenable.
Difficult ethical issues about our use of genetic and reproductive
technologies have already begun to emerge. It is illegal in much
of the world to test fetal gender for the purpose of sex selection,
but the practice is commonplace. A study in Bombay reported that
an astounding 7,997 out of 8,000 aborted fetuses were female, and
in South Korea such abortions have become so widespread that some
65 percent of thirdborn children are boys, presumably because couples
are unwilling to have yet a third girl. Nor is there any consensus
among physicians about sex selection. In a recent poll, only 32
percent of doctors in the United States thought the practice should
be illegal. Support for a ban ranged from 100 percent in Portugal
to 22 percent in China. Although we may be uncomfortable with the
idea of a woman aborting her fetus because of its gender, a culture
that allows abortion at a woman's sole discretion would require
a major contortion to ban this sex selection.
Clearly, these technologies will be virtually impossible to control.
As long as abortion and prenatal tests are available, parents who
feel strongly about the sex of their child will use these tools.
Such practices are nothing new. In nineteenth-century India, the
British tried to stop female infanticide among high-caste Indians
and failed. Modern technology, at least in India, may merely have
substituted abortion for infanticide.
Sex selection highlights an important problem that greater control
over human reproduction could bring. Some practices that seem unthreatening
when used by any particular individual could become very challenging
if they became widespread. If almost all couples had boys, the shortage
of girls would obviously be disastrous, but extreme scenarios of
this sort are highly suspect because they ignore corrective forces
that usually come into play.
Worry over potential sex imbalances is but one example of a general
unease about embryo selection. Our choices about other aspects of
our children's genetics might create social imbalances too -- for
example, large numbers of children who conform to the media's ideals
of beauty. Such concerns multiply when we couple them with visions
of a "slippery slope," whereby initial use, even if relatively
innocuous, inevitably leads to ever more widespread and problematic
future applications: as marijuana leads to cocaine, and social drinking
to alcoholism, gender selection will lead to clusters of genetically
enhanced superhumans who will dominate if not enslave us. If we
accept such reasoning, the only way to avoid ultimate disaster is
to avoid the route at the outset, and we clearly haven't.
The argument that we should ban cloning and human germline therapy
because they would reduce genetic diversity is a good example of
the misuse of extrapolations of this sort. Even the birth of a whopping
one million genetically altered children a year -- more than ten
times the total number of IVF births during the decade following
the first such procedure in 1978 -- would still be less than 1/100
of the babies born worldwide each year. The technology's impact
on society will be immense in many ways, but a consequential diminution
of biological diversity is not worth worrying about.
To noticeably narrow the human gene pool in the decades ahead,
the technology would have to be applied in a consistent fashion
and used a hundred times more frequently than even the strongest
enthusiasts hope for. Such widespread use could never occur unless
great numbers of people embraced the technology or governments forced
them to submit to it. The former could happen only if people came
to view the technology as extraordinarily safe, reliable, and desirable;
the latter only if our democratic institutions had already suffered
assaults so grave that the loss of genetic diversity would be the
least of our problems. While there are many valid philosophical,
social, ethical, scientific, and religious concerns about embryo
selection and the manipulation of the human germline, the loss of
genetic diversity is not one of them. Flesh and Blood As we explore
the implications of advanced reproductive technologies, we must
keep in mind the larger evolutionary context of the changes now
under way. At first glance, human reproduction mediated by instruments,
electronics, and pharmaceuticals in a modern laboratory seems unnatural
and perverted. We are flesh and blood; this is not our place. But
by the same token, we should abandon our vast buzzing honeycombs
of steel, fiber optics, and concrete. Manhattan and Shanghai bear
no resemblance to the African veldt that bore us.
Cocooned in the new environments we have fashioned, we can easily
forget our kinship to our animal ancestors, but roughly 98 percent
of our gene sequences are the same as a chimpanzee's, 85 percent
are the same as a mouse's, and more than 50 percent of a fruit fly's
genes have human homologues. The immense differences between us
and the earth's other living creatures are less a result of our
genetic and physiological dissimilarities than of the massive cultural
construct we inhabit. Understanding this is an important element
in finding the larger meaning of our coming control of human genetics
and reproduction. And if we are to understand the social construction
that is the embodiment of the human enterprise and the source of
its technology, we need to see its larger evolutionary context.
A momentous transition took place 700 million years ago when single
cells came together to form multicellular life. All the plants and
animals we see today are but variations on that single theme --
multicellularity. We all share a common origin, a common biochemistry,
a common genetics, which is why researchers can ferry a jellyfish
gene into a rabbit to make the rabbit's skin fluoresce under ultraviolet
light, or use a mammalian growth-hormone gene to make salmon grow
larger.
Today we are in the midst of a second and equally momentous evolutionary
transition: the human-led fusion of life into a vast network of
people, crops, animals, and machines. A whir of trade and telecommunications
is binding our technological and biological creations into a vast
social organism of planetary dimensions. And this entity's emergent
powers are expanding our individual potentials far beyond those
of other primates.
This global matrix has taken form in only a few thousand years
and grows ever tighter and more interconnected. The process started
slowly among preliterate hunter-gatherers, but once humans learned
to write, they began to accumulate knowledge outside their brains.
Change began to accelerate. The storage capacity for information
became essentially unlimited, even if sifting through that information
on the tablets and scrolls where it resided was hard. Now, however,
with the advent of the computer, the power to electronically manipulate
and sort this growing body of information is speeding up to the
point where such processing occurs nearly as easily as it previously
did within our brains. With the amount of accessible information
exploding on the Internet and elsewhere, small wonder that our technology
is racing ahead.
The social organism we have created gives us not only the language,
art, music, and religion that in so many ways define our humanity,
but the capacity to remake our own form and character. The profound
shifts in our lives and values in the past century are not some
cultural fluke; they are the child of a larger transformation wrought
by the diffusion of technology into virtually every aspect of our
lives, by trade and instantaneous global telecommunications, and
by the growing manipulation of the physical and biological worlds
around us.
Critical changes, unprecedented in the long history of life, are
under way. With the silicon chip we are making complex machines
that rival life itself. With the space program we are moving beyond
the thin planetary film that has hitherto constrained life. With
our biological research we are taking control of evolution and beginning
to direct it.
The coming challenges of human genetic enhancement are not going
to melt away; they will intensify decade by decade as we continue
to unravel our biology, our nature, and the physical universe. Humanity
is moving out of its childhood and into a gawky, stumbling adolescence
in which it must learn not only to acknowledge its immense new powers,
but to figure out how to use them wisely. The choices we face are
daunting, but putting our heads in the sand is not the solution.
Germline engineering embodies our deepest fears about today's revolution
in biology. Indeed, the technology is the ultimate expression of
that revolution because it may enable us to remake ourselves. But
the issue of human genetic enhancement, challenging as it is, may
not be the most difficult possibility we face. Recent breakthroughs
in biology could not have been made without the assistance of computerized
instrumentation, data analysis, and communications. Given the blistering
pace of computer evolution and the Hollywood plots with skin-covered
cyborgs or computer chips embedded in people's brains, we naturally
wonder whether cybernetic developments that blur the line between
human and machine will overshadow our coming ability to alter ourselves
biologically.
The ultimate question of our era is whether the cutting edge of
life is destined to shift from its present biological substrate
-- the carbon and other organic materials of our flesh -- to that
of silicon and its ilk, as proposed by leading artificial-intelligence
theorists such as Hans Moravec and Ray Kurzweil. They believe that
the computer will soon transcend us. To be the "last humans,"
in the sense that future humans will modify their biology sufficiently
to differ from us in meaningful ways, seems tame compared to giving
way to machines, as the Erewhonians so feared. Before we look more
deeply at human biological enhancement and what it may bring, we
must consider what truth these machine dreams contain.
"The Last Human" from Redesigning
Humans: Our Inevitable Genetic Future by Gregory Stock. Copyright
© 2002 by Gregory Stock. Reprinted by permission of Houghton
Mifflin Company.
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