Life 2.0

It last happened about 3.6 billion years ago. a tiny living cell emerged from the dust of the Earth. It replicated itself, and its progeny replicated themselves, and so on, with genetic twists and turns down through billions of generations. Today every living organism—every person, plant, animal and microbe—can trace its heritage back to that first cell. Earth's extended family is the only kind of life that we've observed, so far, in the universe.

This pantheon of living organisms is about to get some newcomers—and we're not talking about extraterrestrials. Scientists in the last couple of years have been trying to create novel forms of life from scratch. They've forged chemicals into synthetic DNA, the DNA into genes, genes into genomes, and built the molecular machinery of completely new organisms in the lab—organisms that are nothing like anything nature has produced.

The people who are defying Nature's monopoly on creation are a loose collection of engineers, computer scientists, physicists and chemists who look at life quite differently than traditional biologists do. Harvard professor George Church wants "to do for biology what Intel does for electronics"—namely, making biological parts that can be assembled into organisms, which in turn can perform any imaginable biological activity. Jay Keasling at UC Berkeley received $42 million from Bill Gates to create living microfactories that manufacture a powerful antimalaria agent. And then there's Craig Venter, the legendary biotech entrepreneur who made his name by decoding the human genome for a tenth of the predicted cost and in a tenth of the predicted time. Venter has put tens of millions of dollars of his own money into Synthetic Genomics, a start-up, to make artificial organisms that convert sunlight into biofuel, with minimal environmental impact and zero net release of greenhouse gases. These organisms, he says, will "replace the petrochemical industry, most food, clean energy and bioremediation."

The notion of creating life in the lab has plenty of detractors. Some scientists aren't convinced it can be done, and religious leaders and environmentalists have expressed their dismay at the idea of tinkering with life (even if it's artificial). Despite the opposition, the researchers who work in the field, which is known as Synthetic Biology, have a disarming casualness about their work—almost as though they were building machines, rather than living things. Indeed, the guiding principle of the field is a conceptualization of living cells as complex computing machines that have the capacity to replicate themselves. The computing analogy for what goes on inside living cells isn't new. Ever since James Watson and Francis Crick discovered the DNA double helix in 1953, molecular biologists have found it useful to imagine genes as software controlling hardware (the cell itself). But SynBio practitioners take the comparison to a new level: they are creating new hardware and software where none existed. SynBio is "oriented to the intentional design, modeling, construction, debugging and testing of artificial living systems," says Tom Knight, a professor at MIT's Artificial Intelligence Lab who now focuses his engineering on microbes. "The genetic code is 3.6 billion years old. It's time for a rewrite."

Such a rewrite is now feasible because the original code—contained within the genomes of naturally evolved organisms (which SynBio practitioners call Life 1.0)—is being deciphered at an accelerating rate. This doesn't mean that we understand everything there is to know about living organisms. But SynBio engineers think they can take what we know and design and construct novel forms of life that are programmed to do practical things that couldn't otherwise be done. "We can now regard cells as 'programmable matter'," says Ron Weiss, a Princeton computer scientist who now writes genetic software for cells. Weiss is convinced that he will soon be able to "program cell behaviors as easily as we program computers."

In the past, genetic wizardry has been confined to tinkering and tweaking what nature has already produced—taking a gene from a bacterium, say, and inserting it into the chromosomes of corn or pigs. What we're talking about is producing life that is wholly new—not in any way a genetic descendant of the primordial Mother Cell. The initial members of each newly created breed will have no ancestors at all.