It seems that researchers may have discovered life on Earth that uses novel biochemistries based on arsenic (certainly a discovery worth publication in Science). If this is the case then this discovery, in some senses, is more exciting than finding evidence of alien life on another planet (at least to a biochemist like me). This is in essence an "alien" life-form, but it lives on Earth and can be more easily studied than some hypothetical life in a far away solar system.The tools and experiments researchers use to look for new forms of life - such as those on missions to Mars - would not detect biochemistries different from our own, making it easy for scientists to miss alien life, even if was under their noses.
"When you don't know what you're looking for or what it'll look like, you have to come up with a whole scientific method for how to go about [looking for] it," added Steven Benner, a Fellow at the Foundation for Applied Molecular Evolution and The Westheimer Institute for Science and Technology in Gainesville, Florida.
Scientists are looking in places where life isn't expected - for example, in areas of extreme heat, cold, salt, radiation, dryness, or contaminated streams and rivers. Davies is particularly interested in places that are heavily contaminated with arsenic, which, he suggests, might support forms of life that use arsenic the way life as we know it uses phosphorus.
If nothing else, we will be able to refine the Drake equation by an iota or more.[PLAIN said:http://www.nasa.gov/home/hqnews/2010/nov/HQ_M10-167_Astrobiology.html]...to[/PLAIN] [Broken] discuss an astrobiology finding that will impact the search for evidence of extraterrestrial life. Astrobiology is the study of the origin, evolution, distribution and future of life in the universe.
I think your conclusion might be premature. I read that to mean that someone has thought of a way that this could be possible. Not that there are actually candidates for life that works this way.It seems that researchers may have discovered life on Earth that uses novel biochemistries based on arsenic (certainly a discovery worth publication in Science).
I could be wrong, but I would find it hard to believe there wouldn't be a leak if it was either 3 or 4. That kind of news would get around very quickly and difficult to contain.3. Finding life.
4. Finding intelligent life.
I'm guessing this would have to be at level 1 or 2. We'll see tomorrow.
I think your conclusion might be premature. I read that to mean that someone has thought of a way that this could be possible. Not that there are actually candidates for life that works this way.
I doubt that a purely theoretical paper speculating about the possible biochemical conditions of extraterrestrial life would make it into Science. There is reason to think that there could be some organisms with novel arsenic biochemistry. For example, in 2008, a team led by the US Geological Survey found organisms that could photosynthesize using arsenic in a lake in California (Kulp et al. Arsenic(III) Fuels Anoxygenic Photosynthesis in Hot Spring Biofilms from Mono Lake, California. Science 321: 967 (2008). http://dx.doi.org/10.1126/science.1160799).There's also level 0 - speculating about conditions that could be compatible with supporting life. Since none of the participants of the conference strike me as the kind that would be able to find anything physical (they are all theorists), we should be closer to level 0 than to level 2.
http://www.timesonline.co.uk/tol/news/science/eureka/article7040864.eceCould the Mono Lake arsenic prove there is a shadow biosphere?
Do alien life forms exist in a Californian lake? Could there be a shadow biosphere? One scientist is trying to find out.
Mono Lake has a bizarre, extraterrestrial beauty. Just east of Yosemite National Park in California, the ancient lake covers about 65 square miles. Above its surface rise the twisted shapes of tufa, formed when freshwater springs bubble up through the alkaline waters.
Felisa Wolfe-Simon, a geobiologist, is interested in the lake not for its scenery but because it may be harbouring alien life forms, or “weird life”. Mono Lake, a basin with no outlet, has built up over many millennia one of the highest natural concentrations of arsenic on Earth. Dr Wolfe-Simon is investigating whether, in the mud around the lake or in the water, there exist microbes whose biological make-up is so fundamentally different from that of any known life on Earth that it may provide proof of a shadow biosphere, a second genesis for life on this planet...
Question about this arsenic thing. It's a substitute for phosphorus, right? But it's not a substitute for COHN-, or even RNA/DNA-based life, right?Simon is investigating whether, in the mud around the lake or in the water, there exist microbes whose biological make-up is so fundamentally different from that of any known life on Earth that it may provide proof of a shadow biosphere, a second genesis for life on this planet...
It has been speculated that the earliest life on Earth may have used arsenic in place of phosphorus in the backbone of its DNA
The hypothetical arsenic-"based" life would still be based primarily on carbon, oxygen, hydrogen and nitrogen. The main difference would be, as said in wikipedia, substitution of arsenic for phosphorus. Felisa Wolfe-Simon and co-authors argue that it is possible that such molecules could exist (without being too unstable to allow life) and why these types of molecules may have been easier for life to use on the early earth in an article in the International Journal of Astrobiology (abstract below):Question about this arsenic thing. It's a substitute for phosphorus, right? But it's not a substitute for COHN-, or even RNA/DNA-based life, right?
This hypothetical arsenic-based life is still organic and based on RNA?
Are you stunned?I would be absolutely stunned if Thursday's Science paper announced they found As-DNA or As-RNA. I could definitely see other aspects of arsenic metabolism (e.g. using it as an electron donor for the fixation of carbon dioxide) and maybe limited incorporation into some biosynthetic pathways, but an organisms with a form of genetic material chemically distinct from all other known organisms would be a huge discovery.
Wow. I went to that page and the video completely froze my system - even the mouse (yet the audio played on). I had to do a hard boot recovery.