Friday, December 03, 2010
Uh, Life is Cleverer
Than We Thought...
DREXELITES. All right. So space travel isn't about NASA anymore. NASA is about, uh, evolution. Come again? Exhibit III:
NASA-funded astrobiology research has changed the fundamental knowledge about what comprises all known life on Earth.
Researchers conducting tests in the harsh environment of Mono Lake in California have discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism substitutes arsenic for phosphorus in its cell components.
"The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. "As we pursue our efforts to seek signs of life in the solar system, we have to think more broadly, more diversely and consider life as we do not know it."
This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth. The research is published in this week's edition of Science Express.
Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur are the six basic building blocks of all known forms of life on Earth. Phosphorus is part of the chemical backbone of DNA and RNA, the structures that carry genetic instructions for life, and is considered an essential element for all living cells.
Phosphorus is a central component of the energy-carrying molecule in all cells (adenosine triphosphate) and also the phospholipids that form all cell membranes. Arsenic, which is chemically similar to phosphorus, is poisonous for most life on Earth. Arsenic disrupts metabolic pathways because chemically it behaves similarly to phosphate.
"We know that some microbes can breathe arsenic, but what we've found is a microbe doing something new -- building parts of itself out of arsenic," said Felisa Wolfe-Simon, a NASA Astrobiology Research Fellow in residence at the U.S. Geological Survey in Menlo Park, Calif., and the research team's lead scientist. "If something here on Earth can do something so unexpected, what else can life do that we haven't seen yet?"
So life isn't what they've been telling us it is. That's cool. But doesn't it make the whole subject a shade less deterministic and accidental than they've been insisting it is? Like, maybe life will find a way to be? And what the hell is life anyway? If it actually, uh, wants to be, independent of the rigid chemical rules organic chemists have been insisting on for two centuries, then shouldn't we be looking harder for some kind of intention or intelligence inside the chemistry?
Nah. I didn't mean to overspeak myself. I'm sure they have a perfect explanation for any deviations from orthodoxy up their sleeve. Intelligence cannot, will not, won't ever be involved in the basic life process. It's simply an emergent property of a certain freakish kind of mammalian brain.
Forget I said anything. I already have.