May 27, 2010 | 20
Craig Venter is the Lady Gaga of science. Like her, he is a drama queen, an over-the-top performance artist with a genius for self-promotion. Hype is what Craig Venter does, and he does it extremely well, whether touting the decoding of his own genome several years ago or his construction of a hybrid bacterium this year. In a typical Venter touch sections of the bacterium’s DNA translate into portentous quotes, such as this one from James Joyce: "To live, to err, to fall, to triumph, and to re-create life out of life."
So I don’t fault Venter for hyping his recent achievement, but I do fault others who should know better, such as the bioethicist Arthur Caplan. "What seemed to be an intractable puzzle, with significant religious overtones, has been solved," Caplan proclaims on this Web site . Venter and his colleagues have "created a novel life-form from man-made parts." Caplan warns that "this hugely powerful technology does need oversight" (no doubt by bioethicists like Caplan).
Actually, Venter has taken just another incremental step in the human manipulation of life, which began millennia ago when our ancestors started breeding dogs and ducks and accelerated recently as a result of advances in biotechnology. In terms of scariness, the synthesis of a poliovirus in 2002 freaked me out much more than Venter’s work.
Venter’s team synthesized and modified DNA from one type of bacteria and inserted the artificial genome into another bacterial species whose own DNA had been extracted. "The form of life that was created was not new," Mark Bedau, a philosopher at Reed College and editor of the journal Artificial Life , said in Science . "What was essentially done was the re-creation of an existing bacterial form of life, except that it was given a prosthetic genome (synthesized in the laboratory), and except that the genome was put into the cytoplasm of a slightly different species."
As Bedau and others point out, scientists still have not come close to creating a living organism from nonbiological materials, especially ones that might have existed on Earth four billion years ago. In other words, scientists have not shown how life began, how inanimate materials become animate.
This problem of life’s origin appears harder today than in 1953, after a 23-year-old graduate student named Stanley Miller filled a glass chamber with methane, ammonia, hydrogen (representing the atmosphere) and water (the oceans). A spark-discharge device zapped the gases with simulated lightning while a heating coil kept the waters bubbling. Within a few days the water and gases were stained with a reddish goo rich in amino acids, the building blocks of proteins. (Jeffrey Bada, a biochemist and former student of Miller, recently reanalyzed Miller’s old samples and discovered that they contain even more amino acids than Miller had realized.)
Miller and other scientists thought that they would quickly demonstrate in detail how genesis unfolded, but that hasn’t happened. When I interviewed Miller in the early 1990s, he admitted that the problem of life’s origin had turned out to be much harder than he had imagined. He was nonetheless still confident that one day scientists would crack the riddle of life’s origin: "It will be in the nature of something that will make you say, ‘Jesus, there it is. How could you have overlooked this for so long?’ And everybody will be totally convinced." Miller died three years ago , his dream unfulfilled.
There are now almost as many theories of life’s origin as there are theorists. Perhaps the most popular is the "RNA world" theory, which posits ribonucleic acid as the first biomolecule. Whereas DNA cannot replicate without the help of enzymes, RNA can act as it own enzyme, snipping itself in two and splicing itself back together again. But RNA and its components are difficult to synthesize in a laboratory, let alone under plausible prebiotic conditions. Moreover, once RNA is synthesized it can make new copies of itself only with a great deal of coaxing by a chemist. Stanley Miller, among others, believed that some simpler—and possibly quite dissimilar—molecule must have paved the way for RNA, but no strong candidate has emerged.
Arthur Caplan declares that Venter and other scientists have dispelled the notion that life "is sacred, special, ineffable and beyond human understanding." Wrong. We still have no idea how life began, or whether life exists only here on our lonely planet or pervades the cosmos. One of the great ironies of modern science is that as we gain more power over life, it remains as fundamentally mysterious as ever.
ABOUT THE AUTHOR
John Horgan, a former Scientific American staff writer, directs the Center for Science Writings at Stevens Institute of Technology. (Photo courtesy of Skye Horgan.)
The views expressed are those of the author and are not necessarily those of Scientific American.