"Life as we know it is universally based on some combination of carbon compounds, but what if life exists based on another element? For instance, silicon," Spock says in an episode of the original series of Star Trek (series one, episode 25 "The Devil in the Dark"). Spock was not far wrong.
Scientists have discovered a life form that can substitute phosphorus, one of the building blocks of life on earth, with arsenic. The research was funded by NASA and it changes the definition of life. Both on earth and elsewhere in the universe. It means life in the universe is no longer dependent on carbon, hydrogen, nitrogen, oxygen, phosphorus and sulphur. These six building blocks are, or should I say were, the basic elements used to build cells in all known life forms on earth. Now a microbe has been discovered that builds parts of itself out of
arsenic. Arsenic is a toxic element to most living organisms. Not to GFAJ-1, a strain of the Gammaproteobacteria. In a lab it was fed on arsenic instead of phosphorus and not only did it survive but it thrived. It incorporated arsenic as part of its biochemistry and happily lived ever after.
"The idea of alternative biochemistries for life is common in science fiction," Carl Pilcher, director of the NASA Astrobiology Institute said. As a writer of many a science fiction story I can not help but feel a slight sensation of vindication. So many discoveries and developments have been predicted by science fiction writers. Yet, still we are often regarded as the dirt under the boot of literature. That will not change with this discovery I think but at least it shows science fiction is a thinking author's game. The imagination we use to create our stories is often based upon that which could be true. That is the root of the popularity of science fiction: no matter how outrageous the idea may seem, somewhere, some day, it might become reality. Apart from the apparent excitement of the story there is an inherent anticipation in science fiction that makes us think ahead about what may be.
The definition of life just changed. This means that life as we don't know it may exist elsewhere in the universe. It means all research done into the chemical make up of planets has to be re-evaluated. Some planets that were deemed not to contain atmospheres conducive to life may on second thoughts be teeming with little green creatures. Creatures that are chuckling at our narrow minds for thinking that life could only be defined by the narrow bounds we put upon it. Only six elements to build with? Pfah! Science has just received yet another lesson in the amount of 'thinking outside the box' nature is capable of. Once again Mother Nature showed us that to define and categorise may be a human hobby, it has nothing to do with her. I bet that Mother Nature loves
science fiction
stories.
