Carbon-silicon bonds: Is this a new model for alien life?

Silicon-based life? Scientists say that the directed evolution technique could open the door to interesting future discoveries. 

|
Mark Wilson/Roswell Daily Record/AP/File
Contestants prepare to take the stage during the 2013 UFO Festival Alien Costume contest in Roswell, N.M. in 2013.

Silicon-based life, a longtime staple of science fiction, just took a step closer to becoming reality.

In a paper published in the journal Science on Thursday, scientists revealed a revolutionary technique to urge silicon to bond naturally with carbon, opening the door to a wide range of possibilities for both human engineering and alien life.

"It's like breeding a racehorse," said Frances Arnold, study coauthor and chemical engineering professor at Caltech. "A good breeder recognizes the inherent ability of a horse to become a racer and has to bring that out in successive generations. We just do it with proteins."

Silicon has long intrigued scientists because it is so abundant, yet life on Earth is exclusively carbon based. While scientists have artificially bonded silicon and carbon, no living organism is known to put the two together.

“Poor silicon, abundant in the Earth, but rejected by the biosphere for its wondrous evolutionary tinkering,” said Cornell University chemist Roald Hoffmann in a press release.

Using a method called directed evolution, scientists mutated an enzyme called cytochrome c to catalyze a bonding reaction between silicon and carbon.

Cytochrome c, which comes from an extremophile bacterium that lives in Icelandic hot springs, can create chemical bonds between silicon and carbon fifteen times more efficiently than synthetic catalysts, proving that in this instance, natural is definitely better.

"This iron-based, genetically encoded catalyst is nontoxic, cheaper, and easier to modify compared to other catalysts used in chemical synthesis," said postdoctoral scholar and study lead author Jennifer Kan in a press release. "The new reaction can also be done at room temperature and in water."

Directed evolution itself is not a new idea. Dr. Arnold invented the technique in the 1990s, and has won the Millennium Technology Prize for her efforts. In the past, scientists have used directed evolution to create better enzymes for modifying plants or animals for commercial uses – better fuel or food supplies.

This is the first time, however, that chemists have used the method to bond silicon and carbon. Like carbon, silicon can form four bonds, making it an ideal potential building block of life, as it can form long chains of molecules.

The practical applications of their discovery are interesting to scientists, who say that the study opens the door to an exciting future.

Scientists say that the study could have interesting implications for the pharmaceutical industry.

Most importantly, however, researchers say that the study shows that natural silicon-carbon bonds are certainly possible. What this means for the possibility of silicon-based life forms elsewhere is yet to be seen, although scientists have long considered that alien life may not be carbon-based like life on Earth.

In the past, researchers studying the possibilities of silicon-based life forms have noted the difficulty of creating compounds that are completely analogous to carbon-based compounds.

Researchers say, however, that their new discovery is proof positive that nature is even more adaptable than we had previously imagined.

"This study shows how quickly nature can adapt to new challenges," Arnold said in a press release.

"The DNA-encoded catalytic machinery of the cell can rapidly learn to promote new chemical reactions when we provide new reagents and the appropriate incentive in the form of artificial selection," she said. "Nature could have done this herself if she cared to."

You've read  of  free articles. Subscribe to continue.
Real news can be honest, hopeful, credible, constructive.
What is the Monitor difference? Tackling the tough headlines – with humanity. Listening to sources – with respect. Seeing the story that others are missing by reporting what so often gets overlooked: the values that connect us. That’s Monitor reporting – news that changes how you see the world.

Dear Reader,

About a year ago, I happened upon this statement about the Monitor in the Harvard Business Review – under the charming heading of “do things that don’t interest you”:

“Many things that end up” being meaningful, writes social scientist Joseph Grenny, “have come from conference workshops, articles, or online videos that began as a chore and ended with an insight. My work in Kenya, for example, was heavily influenced by a Christian Science Monitor article I had forced myself to read 10 years earlier. Sometimes, we call things ‘boring’ simply because they lie outside the box we are currently in.”

If you were to come up with a punchline to a joke about the Monitor, that would probably be it. We’re seen as being global, fair, insightful, and perhaps a bit too earnest. We’re the bran muffin of journalism.

But you know what? We change lives. And I’m going to argue that we change lives precisely because we force open that too-small box that most human beings think they live in.

The Monitor is a peculiar little publication that’s hard for the world to figure out. We’re run by a church, but we’re not only for church members and we’re not about converting people. We’re known as being fair even as the world becomes as polarized as at any time since the newspaper’s founding in 1908.

We have a mission beyond circulation, we want to bridge divides. We’re about kicking down the door of thought everywhere and saying, “You are bigger and more capable than you realize. And we can prove it.”

If you’re looking for bran muffin journalism, you can subscribe to the Monitor for $15. You’ll get the Monitor Weekly magazine, the Monitor Daily email, and unlimited access to CSMonitor.com.

QR Code to Carbon-silicon bonds: Is this a new model for alien life?
Read this article in
https://www.csmonitor.com/Science/2016/1126/Carbon-silicon-bonds-Is-this-a-new-model-for-alien-life
QR Code to Subscription page
Start your subscription today
https://www.csmonitor.com/subscribe