Monday, February 4, 2008

Did Life Begin in Ice?

Remember my post about an icy origin of life? Well, I just found the full article over at Discover Magazine's website. Be sure to check it out, and read the whole thing (it is four pages but worth it).

Some Quotes:

"Miller had filled the vial in 1972 with a mixture of ammonia and cyanide, chemicals that scientists believe existed on early Earth and may have contributed to the rise of life. He had then cooled the mix to the temperature of Jupiter’s icy moon Europa—too cold, most scientists had assumed, for much of anything to happen. Miller disagreed. Examining the vial in his laboratory at the University of California at San Diego, he was about to see who was right.

As Miller and his former student Jeffrey Bada brushed the frost from the vial that morning, they could see that something had happened. The mixture of ammonia and cyanide, normally colorless, had deepened to amber, highlighting a web of cracks in the ice. Miller nodded calmly, but Bada exclaimed in shock. It was a color that both men knew well—the color of complex polymers made up of organic molecules. Tests later confirmed Miller's and Bada’s hunch. Over a quarter-century, the frozen ammonia-cyanide blend had coalesced into the molecules of life: nucleobases, the building blocks of RNA and DNA, and amino acids, the building blocks of proteins. The vial’s contents would support a new account of how life began on Earth and would arouse both surprise and skepticism around the world."

"Biebricher sealed small amounts of RNA nucleobases—adenine, cytosine, guanine—with artificial seawater into thumb-size plastic tubes and froze them. After a year, he thawed the tubes and analyzed them for chains of RNA.
For decades researchers had tried to coax RNA chains to form under all sorts of conditions without using enzymes; the longest chain formed, which Orgel accomplished in 1982, consisted of about 40 nucleobases. So when Biebricher analyzed his own samples, he was amazed to see RNA molecules up to 400 bases long. In newer, unpublished experiments he says he has observed RNA molecules 700 bases long. Biebricher’s results are so fantastic that some colleagues have wondered whether accidental contamination played a role. Orgel defended the work. “It’s a remarkable result,” he said. “It’s so remarkable that everyone wants better evidence than they would for an unremarkable result. But I think it’s right.”"


Narrow said...

Wow, that was a great article. A very interesting perspective on the actual origins of life. It's a real shame he was never able to fully complete his work.

Baal's Bum said...

Absolutely fascinating