This week's issue of Nature features a welcome discovery for those of us enthralled, mystified and frustrated by the study of the origins of life.
John Sutherland, a chemist at the University of Manchester, and his colleagues claim to have figured out how ribose, phosphate and the nitrogenous (nitrogen-bearing) molecules known as nucleobases first came together to form nucleotides—the building blocks of the RNA world from which life is thought to have emerged.
"My assumption is that we are here on this planet as a fundamental consequence of organic chemistry," Sutherland told The New York Times. His secret was running the experiment in stages, only adding phosphate in the final step. So far, the team has succeeded in building two of the four nucleotides; the molecule pictured [left] is cytosine, the nucleobase that, until now, scientists were unable to combine with sugars and phosphates to form the RNA nucleotide ribocytidine phosphate.*
Is the latest discovery a real breakthrough or just another high-profile paper to tease the navel-gazers of the science world? Jack Szostak of the Massachusetts General Hospital wrote in a commentary that the new discovery "will stand for years as one of the great advances in prebiotic chemistry."
The findings also serve as a reminder that the pace of scientific discovery does not always move as quickly as scientists would like. In 1871 Darwin first postulated that life began in a "warm little pond, with all sorts of ammonia and phosphoric salts."
Almost a century later, Stanley Miller conducted the great-grandaddy of origin-of-life studies at the University of Chicago with his colleague Harold Urey, experiments which left scientists with more questions than they answered.
In 1994 Leslie Orgel wrote in the pages of Scientific American that growing evidence was supporting the theory that life emerged from RNA, but he despaired, "how that RNA came into being remains unknown." Last year, scientists got perhaps a little bit too giddy when some minor results were published in Science based on forgotten vials from the original Miller–Urey studies.
Chemist Robert Shapiro of New York University, who wrote about his alternative theory on the origin of life for Scientific American in 2007, told Chemistry World that Sutherland's results "have nothing to do with the origin of life on Earth whatsoever."
*Correction (5/15/09): This sentence was changed after posting. It originally incorrectly identified cytosine as a nucleotide.
Cytosine image via Wikimedia Commons