Specifically, a borax-containing mineral known as colemanite helps convert organic molecules found in interstellar dust clouds into a sugar, known as ribose, central to the genetic material called RNA. This announcement provides a key step toward solving the 3-billion-year-old mystery of how life on Earth began. The findings will appear in Friday's issue of the journal Science. Steven Benner, Alonso Ricardo, Matthew Carrigan and Alison Olcott built on a famous experiment done 50 years earlier by Stanley Miller that is found in many textbooks. In 1953, Miller showed that electric sparks in a primitive atmosphere made amino acids, the building blocks of proteins.
Miller's experiment failed to identify sugars that were needed for genetic material, however. "The sugar ribose can be formed from interstellar precursors under prebiotic conditions," said Benner, who led the research funded by NASA, the National Science Foundation and The Agouron Institute in Pasadena, Calif. "But ribose is too unstable to survive under Miller's conditions." Ribose, like most sugars, turns into tar if not handled carefully. "It is like baking a cake too long," said Benner, a UF distinguished professor of chemistry and anatomy and cell biology. In 1995, Miller gave up trying to make ribose prebiotically, writing: "The first genetic material could not have contained ribose or other sugars because of their instability."
Benner, who also is a member of NASA's Astrobiology Institute, did the first experiments as an instructor at an international geobiology course last summer funded by the Agouron Institute and held at the University of Southern California Wrigley Institute for Environmental Studies.
"We asked two questions. First, what simple organic molecules might have been present on early Earth as st
Contact: Steven Benner
University of Florida