Life as We Don't Know It
Carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur -- the six basic building blocks of all known forms of life on Earth -- Unitil now. 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. This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth.
Comments:
This:<br><br>"The microorganism substitutes arsenic for phosphorus in its cell components." <br><br>is really overstating what was actually found.<br><br>This link, a good short read, links to a longer article by microbiologist Rosie Redfield at the University of British Columbia.<br><br>http://sandwalk.blogspot.com/2010/12/arseic-and-bacteria.html<br><br><br><br>
If this little critter is doing the chemistry the paper claims it is, we are in for an interesting time in biochemistry.<br><br>The initial knee-jerk howls will give way to dogged research, and that’s good for science whether or not the paper holds up.<br><br>By now, about a zillion grant proposals are already through their first draft. Enough of these proposals will be funded to figure out what’s going on here, and we might be far more surprised by what comes of that research than what we see in this paper.<br><br>That said…<br><br>It’s been a long time since anyone seriously questioned the basic chemistry of life. Bring it on!<br><br>While I’m not at all ready to accept that GFAJ-1 (Halomonadaceae) is the descendant of a second genesis, I have always been skeptical of a single genesis on this (or any other) planet. GFAJ-1 at least begs the question. An equal question is whether our Phosphate-based branch is an evolution of an earlier GFAJ-1 type ancestor. Or... Or... Or...<br><br>If the chemistry apparently exhibited by this this critter is a product of evolution triggered by the (recent) changes in Mono Lake, then it has evolved with remarkable speed. It’s only been about 50 years since the fresh water intake of Mono Lake was cut off. <br><br>If the chemistry of GFAJ-1 has been running on Arsenate for a much longer time, then we’ll almost certainly find a number of other organisms in other environments doing the same kind of thing, perhaps with different elements being substituted. <br><br>Either way, we may have a lot to learn.<br><br>Or, the whole thing falls apart, and we discover that we have serious flaws in our research tools (or the way they were applied to generate this paper) that need fixing. That outcome would be just as beneficial in the long run.<br><br>-Dave Graham
But if this bacteria evolved from native earth chemistry (even if artificially altered), it would not seem to support an independant "Genesis". Correct? To say this would support the notion of life evolving under different alien chemistry seems spurious considering the researchers started with a native life form as a "building block". <br>I'm just a hobbyist in the insurance industry, so don't beat me up to bad if I'm completely off base here.
I for one welcome our new arsenic based overlords.
Some scientists claiming the study was poorly done and should not have been published! Time to get the popcorn out. <br><br>http://www.slate.com/id/2276919<br><br>
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