Sample text for Redesigning humans : our inevitable genetic future / Gregory Stock.

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The Last Human

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
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
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
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
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.

Copyright © 2002 by Gregory Stock. Reprinted by permission of
Houghton Mifflin Company.

Library of Congress subject headings for this publication: Human genetics Moral and ethical aspects, Human reproductive technology Moral and ethical aspects, Genetic engineering Moral and ethical aspects