Silicon-Based Life on Earth Is Closer to Reality Than You Realize: Study
Life on Earth is rooted in carbon. Silicon-based life sounds like the stuff of science fiction, but a new research shows just how the evolution of nature could lead to the incorporation of silicon in carbon-based molecules. According to a report from Live Science, scientists have found a way to chemically bind carbon and silicon to each other.
In the 1990s, senior author Frances Arnold of the California Institute of Technology (Caltech) in Pasadena pioneered a method called "directed evolution," which includes manipulating microbes into creating unique molecules. For the recent research, Arnold and his team wanted to create enzymes that are able to generate organo-silicon compounds.
The group started by selecting enzymes that could potentially manipulate silicon chemically. Then, they mutated the DNA blueprints of these enzymes over and over again until they reached their desired results.
The researchers eventually focused on a heme protein cytochrome c from the bacterium Rhodothermus marinus. This heme protein is known to transfer electrons to other proteins in the microbe, but the team discovered that it could also produce low levels of organo-silicon compounds. Only three rounds of mutations are needed to transform cytochrome c into a catalyst that's able to generate carbon-silicon bonds more efficiently than synthetic techniques.
"The biggest surprise from this work is how easy it was to get new functions out of biology, new functions perhaps never selected for in the natural world that are still useful to human beings," Arnold explained. "The biological world always seems poised to innovate."
While these findings could take a while to analyze in the context of alien life, the successful laboratory experiment does raise the possibility of microbes creating these molecules naturally in the real world.
"In the universe of possibilities that exist for life, we've shown that it is a very easy possibility for life as we know it to include silicon in organic molecules," Arnold pointed out. "And once you can do it somewhere in the universe, it's probably being done."
The study is published in the journal Science.