Scientists say they've gained new insights into a famous experiment that attempted to create in a laboratory the conditions that may have led to the creation of life on Earth.
In that celebrated experiment at the University of Chicago, performed in 1953, an electrical charge was passed through a chamber containing gases believed to have dominated Earth's atmosphere between 3,000 million and 4,500 million years ago.
The gases, hydrogen, methane, ammonia and water vapor, when exposed to the charge, yielded long chain amino acids, considered the basic building blocks of life.
In a new study recreating the original work known as the Miller-Urey experiment and examining it in closer detail than ever before, researchers say they may have discovered an important and previously intermediate state on the path from molecules to acids.
The scientists from Italy and France used computer models of quantum mechanical effects to simulate behavior of atoms and electrons in a strong electric field such as was used in the original experiment to "observe" the chain of events occurring in the reactions.
"We are doing this on a picosecond timescale, looking at the very early steps of Miller-like reactions," says researcher A. Marco Saitta of the Université Pierre et Marie Curie in Paris.
The new model yields the same results at the Miller-Urey work, but suggests the products formed out of it come about in ways significantly different than previously thought, the researchers say.
Formaldehyde was previously believed to be the intermediate product between the gases and the formation of the amino acid glycine, but their simulation suggests a different intermediate, formamide, is in fact involved.
Because formamide has been seen in space linked with the icy bodies of comets, it raises new questions about the origin of life on Earth -- and possible elsewhere, the researchers say.
"The possibility of new routes to make amino acids without a formaldehyde intermediate is novel and gaining ground, especially in extra-terrestrial contexts," they say in a report of their study published in the Proceedings of the National Academy of Sciences in the U.S.
"The presence of formamide might be a most telling fingerprint of abiotic terrestrial and extra-terrestrial amino acids."
Other scientists say they welcome a new look at a classic experiment on the possible early creation of life on Earth.
Saitta and his partner Franz Saija of the Institute for Chemical and Physical Processes in Italy have provided "new insights into the idea that electrical discharges, for example lightning, could have played a role in the formation of prebiotic molecules on early Earth," says Nir Goldman of the Lawrence Livermore National Laboratory in California.
