NASA was WRONG on arsenic-gobbling aliens, claim boffins Scientists in Switzerland have blown apart the theory that some bacteria can live off arsenic, disproving a controversial 2010 study by NASA. Felisa Wolfe-Simon, one of the space agency's astrobiologists, faced scepticism when she declared two years ago that she had discovered the snappily named GFAJ-1* microbe thriving in the …
Of course bacteria metabolise phosporus. Just like you and I do. You need phosphorus like you need a hoie in your arse. This isn't about using elemental arsenic or phosphorus as food. It's about substituting arsenic for phosphorus in metabolic processes such as the conversion of ADP to ATP to store energy and releasing it by converting ATP to ADP.
(ADP is Adenosine Di-Phospate, the T is for Tri-. Phosphorus and arsenic are Group 15 elements with similar chemistry, like carbon and silicon in Group 14, for example)
ObDisc: other adenosine phosphates, other nulcleotide phosphates and other phosphate metabolites are available.
Mine's the one with the tatty copy of Lehninger in the pocket.
The media was responsible for making this such a big deal & they got it wrong/jumped the gun.
The original paper stated contamination of the samples was a significant possibility & the group made shed loads of samples available for that reason. The media really muddies the water for science because they don't understand the processes involved and end up forcing scientists into headline quotes: Most scientists are not equipped to deal with media sharks & it makes a poor impression on laymen. I often wish media would stay out of the journals as they rarely know what they're talking about.
>The media should stop reading scientific journals
..especially those scientifically-illterate journalists with their media studies degrees who seem to be able to read an abstract and get (intentionally?) entirely the wrong end of the stick every single time. Still, they can always get employment at the Telegraph, it seems.
Nowhere is this done more than with statistics. A credible scientist will state confidence levels, standard deviations and other measures to qualify their findings.
The journalists strip out the "boring stuff" and reduce the contents to what their readership understands. Fist to go are confidence measures and other qualifications. Next, medians become averages.
All that is left is enough pap to stand a snappy headline on. "Microbes Lick Lips for Arsenic"
but didn't the whole affair start with NASA announcing an "important" (as in hint, hint, we've found life on Mars) only to follow it up with this piece of mostly speculation. In the circumstances the media can be forgiven for trying to make the best out of the very little they were given.
We always bang on about about "earth" like planets to support life.
Ok in this instance they got it wrong, but that's because life has evolved to suit our environment.
What is to say, on another planet that has a surface temp of -100c, has an atmosphere of pure methane and the "oceans" are liquid nitrogen, that life has not evolved there, for the simple reason that is what those specific life-forms require to survive. Heck they could be doing research going, "carbon based life-forms requiring oxygen and water? Don't be so stupid, nothing could survive in those conditions!"
You are partially wrong and partially right. In a infinite universe ootentially anything can happen. In chemical reactions for any given combination of conditions there are a finite set of results and even less that would lead to life as we understand it. A great example is increased solar and cosmic radiation than we get tends to smash and damage the complex molecules that lead to life. Is life still possible under these conditions? Possibly but unlikely.
Therefore on that basis we more accurately say that based on our current understanding of chemistry the changes of life arising are slim.
I dont think its arrogance - just more like forgetfulness and failure to state things in terms of probabilities.
Except this ain't Star Trek, and we can't (easily) just go out and seek new life and new civilisations. On a generation ship (the only way to do it right now), the end aim would be setting up a colony out there. If we wanted to go and orbit a planet that's utterly hostile to our brand of life, we've got a bunch of them in our own solar system - we don't need to go looking further afield.
What Anna Leach actually wrote was, "Scientists in Switzerland have blown apart the theory that some bacteria can live off arsenic..." Omission of the word 'some' in the quotation changes the meaning radically.
The NASA research had suggested that 'some bacteria' could substitute arsenic for phosphorus; and this research has now been shown to be flawed.
There is a problem that faces proponents of panspermia and wannabe space cadets in that there seems to be essentially no observable trace of phosphorus in comets and other objects in space such as Mars. This suggests that there isn't much likelihood of finding organic life nearby, because where there's life as we know it there's phosphorus. Without the prospect of aliens, interest in space exploration declines; and this leads to a fall in NASA's funding.
If I remember correctly, NASA had been very cheerful about the original arsenic research, and had promoted it quite strongly in pop-sci media. It would mean that alien life-forms could survive without needing phosphorus! This was despite a somewhat cool reception from the majority of biologists and biochemists who found the suggested metabolism implausible for a number of reasons, most of which had not been addressed.
Imagination and novelty is vital in forming new hypotheses. But sometimes when it turns into fantasy for funding it really does need to be "blown apart".
«there exists at least one (and we have found it)». Not being a specialist in the area, it's beyond me to pick holes in the original paper by Wolfe-Simon et al (https://e-reports-ext.llnl.gov/pdf/457014.pdf) and since the recent Science article (http://www.sciencemag.org/content/early/2012/07/06/science.1218455) by the Swiss researchers lies behind a paywall, I've been unable to access that, but the problem here seems to me to lie not so much in that that the first team were perhaps less careful in carrying out their experiments than they should have been and that new research indicates that the claims of substitution of As for P in nucleic acids of a certain Halomonadaceae strain were erroneous, but rather in that the first result was blown out of all proportion (due, perhaps, as David Pollard writes, to «fantasy for funding») in reporting to the media. Given the level of scientific literacy among journalists - and, perhaps still more importantly, the fact that «revolutionary» claims («faster-than-light neutrinos», anyone ?) sells advertising - I'm not at all surprised....
In any event, I'm glad to hear that our space-alien overlords will most likely use PO3 rather than ASO4 in their nucleic acids - 'twill no doubt help us relate to each other, before they eat us or whatever space-alien overlords do....
Henri
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