True to modern form, NASA has announced that a different for of life was discovered; But on Earth.
This is huge actually, because it opens up criteria in which alien life could be discovered in various extraterrestrial/extrasolar planets:
NASA-Funded Research Discovers Life Built With Toxic Chemical12.02.10
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?”
The newly discovered microbe, strain GFAJ-1, is a member of a common group of bacteria, the Gammaproteobacteria. In the laboratory, the researchers successfully grew microbes from the lake on a diet that was very lean on phosphorus, but included generous helpings of arsenic. When researchers removed the phosphorus and replaced it with arsenic the microbes continued to grow. Subsequent analyses indicated that the arsenic was being used to produce the building blocks of new GFAJ-1 cells.
The key issue the researchers investigated was when the microbe was grown on arsenic did the arsenic actually became incorporated into the organisms’ vital biochemical machinery, such as DNA, proteins and the cell membranes. A variety of sophisticated laboratory techniques was used to determine where the arsenic was incorporated.
The team chose to explore Mono Lake because of its unusual chemistry, especially its high salinity, high alkalinity, and high levels of arsenic. This chemistry is in part a result of Mono Lake’s isolation from its sources of fresh water for 50 years.
The results of this study will inform ongoing research in many areas, including the study of Earth’s evolution, organic chemistry, biogeochemical cycles, disease mitigation and Earth system research. These findings also will open up new frontiers in microbiology and other areas of research.
“The idea of alternative biochemistries for life is common in science fiction,” said Carl Pilcher, director of the NASA Astrobiology Institute at the agency’s Ames Research Center in Moffett Field, Calif. “Until now a life form using arsenic as a building block was only theoretical, but now we know such life exists in Mono Lake.”
The research team included scientists from the U.S. Geological Survey, Arizona State University in Tempe, Ariz., Lawrence Livermore National Laboratory in Livermore, Calif., Duquesne University in Pittsburgh, Penn., and the Stanford Synchroton Radiation Lightsource in Menlo Park, Calif.
NASA’s Astrobiology Program in Washington contributed funding for the research through its Exobiology and Evolutionary Biology program and the NASA Astrobiology Institute. NASA’s Astrobiology Program supports research into the origin, evolution, distribution, and future of life on Earth.
Not as dramatic as finding little critters on Mars, but it could explain issues like the lack of acetyline in the atmosphere of Saturn’s moon Titan.
For once looks good on NASA!
When it comes to NASA, I go by the maxim “Not A Straight Answer”, which I followed since 1977 when NASA denied finding life via the Viking Landers.
And I’m not going to mention The Face on Mars, that’s a totally different subject altogether.
So when they announced November 29th, 2010 there was a big to-do that would affect astrobiology, well, I went ho-hum.
But as usual, my natural nosiness won out and I started keeping track of the mainstream news feeds spewing the propaganda just on the off chance there was something to this:
Science fans across the Internet are eagerly awaiting an announcement from NASA’s astrobiology team planned for Thursday. All NASA will say about the press conference is that it will “discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life.”
Evidence of Life on Mars?
While many are hoping that NASA will announce that extraterrestrial life has been discovered, this seems like a near impossibility. If this were the case, the best prospect for this might be from Mars. The Exploration Rover Spirit has been stationary for just about a year after getting stuck in some soft sand. That would give it an opportunity to study that patch of sand over a long period of time, during which it might perceive chemical changes attributable to life processes. It’s a long shot at best, but remember that in the spot where it is stuck, Spirit was looking at layered sulfate salts associated with ancient thermal vents that could have been a prime location for bacterial life at some point in the Red Planet’s distant past.
A New Chemical Basis for Life?
More likely is that a group of NASA astrobiologists has discovered a chemical model for life based on something other than oxygen and water. Such a discovery might open up the number of potential sites where extraterrestrial life might be found and would be a major breakthrough in the field. Looking at the team of scientists that NASA lists as attending the press conference, perhaps we can gain some further insight.
Dr. James Elser
The biography of Dr. James Elser at his Arizona State University webpage, describes his work as “the study of balance of energy and multiple chemical elements in living systems.” His inclusion might suggest an exotic chemical basis for life is being announced.
Dr. Stephen Benner
Dr. Stephen Benner. A professor of Molecular Cell Biology at the University of Florida, Gainesville, describes his work in astrobiology as working “to identify molecular structures that are likely to be universal features of living systems regardless of their genesis, and not likely products of non-biological processes… As part of the team defining the architecture of the Mars landing missions, the Benner group will have the opportunity to test these as part of a search for life on Mars.” This might lend some credence to the notion that the press conference will announce evidence of past life on Mars.
Dr. Pamela Conrad
NASA’s Pamela Conrad has co-authored “The Bread-crumb trail: distribution of organic chemical biosignatures from cryptoendolithic communities on the surfaces of Arctic and Antarctic sandstone rocks.” This again would support the idea that evidence of past life may have been discovered in the Martial soils.
Dr. Felisa (IronLisa) Wolfe-Simon
Dr. Felisa Wolfe-Simon of the U.S. Geological Survey, also working with the NASA astrobiology team, says on her website that she is working “as part of the NASA Astrobiology Institute we are examining arsenate-rich environments to hunt and enrich cultures for organisms utilizing arsenate in novel and unique modes.” She also mentions that this work involves Dr. Stephen Benner. Her inclusion strongly suggests that a chemical model for arsenic based life has been discovered, and perhaps, in looking at the other specialties involved, they have found a way of identifying unique chemical signatures left by this type of organism that would rule out non-living origins for these materials. This would provide a new way to search for signs of life on other planets.
Dr. Mary Voytek
The team leader is NASA’s Dr. Mary Voytek. NASA says her work is in the area of “environmental controls on microbial transformations of nutrients, xenobiotics, and metals in freshwater and marine systems.” This might support the idea of a new identifiable chemical signature which might be left behind by certain types of bacterial or prebiotic life.
The Best Guess about the NASA astrobiology announcement
My guess, and it is only a guess, is that a new chemical basis for life has been modeled resulting in the discovery of a unique chemical signature that, if found in an extraterrestrial rock (or a terrestrial rock, for that matter), would be a smoking gun for the past presence of this type of life. Perhaps, they have even actually found such evidence, either with a visual examination of martial soils by the rovers, or in meteorite fragments found in the arctic.
I won’t be able to listen to NASA’s news conference at 2:00 p.m. today, but hopefully I can get the gist of it later on tonight.
Maybe NASA will prove me wrong this time.