Scientists have taken a significant step toward creating artificial life by transplanting computer-designed genetic material into a bacteria cell, forming a new strain of the bacteria.
The work, while a significant scientific breakthrough, touches on profound questions regarding the origins and nature of life, some analysts say.
One of the ultimate goals of the project, the scientists say, is to develop the ability to design microbes from scratch to perform functions ranging from converting carbon-dioxide into oil and cleaning up pollution to serving as tiny machines for speeding the manufacture of vaccines.
The effort, reported in Friday's issue of the journal Science, does not represent a complete from-scratch organism.
Instead, the team used computer data on an existing bacterial genome as a template. Then they digitally modified the genome, adding their own formulations – including genetic material that encoded the researchers' names and three literary quotes in a kind of artist's signature that verified the genetic material the bacterial cell took up was the synthetic form.
So the effort remains a proof of principle, says J. Craig Venter, who heads the J. Craig Venter Institute in Rockville, Md., and led the research effort. Much work remains before researchers attain the ability to design and make fully custom microbes.
Still, the first colony of synthetic cells represents a biological and philosophical watershed.
"This is the first self-replicating species on the planet whose parent is a computer," Dr. Venter said during a press briefing Thursday announcing the results. "The cell started with a digital code in a computer."
The team used that information to build a bacterial chromosome essentially from four bottles of chemicals. They used yeast as a factory for assembling smaller segments of the chromosome into ever-larger segments. Then they transferred the entire new chromosome into a recipient cell, whose internal chemistry activated this assembly of genes.
Beyond the technical accomplishment – and the inevitable concerns about the safety and ethics of this fledgling technology – lies what may be a more profound implication of the work, according to University of Pennsylvania bioethicist Arthur Caplan.
Since Aristotle, he explains, scientists, philosophers, and theologians have argued over whether life involves more than chemical components – some have called it a "soul," others élan vital, a vital force that distinguishes the living from the nonliving.
Venter's team has shown that with the right mix of inanimate chemicals to build DNA sequences, and the right soup within the cell receiving the DNA, the result is a living organism, Dr. Caplan says.
The concept isn't alien to biologists, particularly those probing the origins of life on Earth. Yet Venter's work could be seen as the "final word in favor of mechanistic reductionism" of organic life, he says. "That's the enormous significance of this work."
Indeed, the work highlights a broad trend in the physical and biological sciences – one that over the past several decades has evolved to give humanity the ability to manipulate inanimate, and now animate, matter at its most fundamental levels and in forms of uniquely human design.
Even as the science of synthetic biology has evolved, so has the discussion of implications of this field, notes Gregory Kaebnick, an research scholar at the Hastings Center, a bioethics think tank in Garrison, N.Y.
Yet at this stage, he says, the nascent technology may raise hackles unnecessarily.
"I'm very sympathetic about concerns over how biotechnology may change the human relationship with nature," he says. "Synthetic biology can look like the culmination of the threat biotechnology can pose" to this relationship.
"But to my lights it doesn't pose a serious threat," he adds. Up to now, synthetic biology has focused on microbes, not complex organisms like plants or cows. "And the things we are doing to them are restricted to industrial uses," he adds.
Moreover, the aim is to simplify the genomes so that organisms spend most of their energy on producing the products -- fuels, pharmaceuticals, pollution-clean-up agents, for instance. Removing all but the most essential genes makes the organisms less adaptable to stress, and so less able to survive outside of a carefully controlled environment, Dr. Kaebnick says.
Still, taking advantage of any benefits from crossing the threshold from swapping "natural" genes among living organisms to designing synthetic genomes will require that scientists pay close attention to public concerns, according to David Ropeik, a risk-management consultant and former instructor on risk at the Harvard School of Public Health.
Because many of the developments leading to Thursday's announcement have remained fairly low on the public's radar screen, he says he anticipates that Venter's latest results could trigger the kind of public outcry that led researchers in the 1970s to place a temporary moratorium on gene-splicing research, then in its infancy. Leaders in the field met to work out a set of "how we need to be careful" protocols for conducting the work, Mr. Ropeik recalls.
That act alone, he says, signaled that researchers recognized and respected public concerns about the work they were undertaking.
The same is needed today, he says.
"What's really important for all the progress this work promises is that people's concerns be taken seriously and get factored in to how scientists behave and proceed," he says.
Venter notes that his group has been briefing politicians and regulators along the way, and the work has been reviewed by ethicists, including Dr. Caplan.
But the efforts may now have to be played out on a larger stage, and the work may need some self-imposed limits.
A report on synthetic biology produced by the University of Nottngham's Institute for Science and Society in Britain noted that "it must be recognised that ... some ethically problematic scientific projects and potentially controversial technologies may have to be abandoned in order to maintain trust."