Monday, December 06, 2010

Judging the experts on the arsenic-bacteria pushback

Here's an angry pushback contradicting the implications of the recent Science article finding Mono Lake bacteria that could use arsenic instead of phosphorus. It's interesting from my perspective because I know virtually nothing about the field and am completely incompetent to judge its validity, but it feels like the pushback you see from the 3% of climatologists who have some doubts about climate disruption. It does sound "sciencey", which must be what climate skeptics think when they read something from Lindzen or Michaels telling them what they want to hear.

In this case, my worth-little gut reaction is that she might have a point. A big difference from people like Pielke Sr. and Judith Curry is that Redfield seems to be attracting support from experts (see the comments), instead of incredulous looks. And she's pushing back on a single paper at the cutting edge of new research, instead of trying to overturn decades of established knowledge. Finally, while her certainty in the post is offputting (as is her attacks on the Mars meteorite researchers, one of whom was a housemate of mine), she's much more reasonable in response to comments that criticize her post.

Should be interesting to see where this goes.

UPDATE: As Eli comments below, the problem may be pushing a cool discovery far beyond where it belongs. I posted something relevant to Rosie Redfield's blog:

This part of the OP interested me, re that either P or As had to be added for the bacteria to grow:

"(21) Agreed, with the proviso that the media be tested and shown to be identical except for the phosphate and arsenate. But this wouldn't mean that arsenic replaced phosphorus in any biological molecules in GFAJ cells, just that the cells needed arsenate for something."

That cells needed arsenate for something would be an interesting finding, I'd guess. And cells need As for something that P does is also implied by this finding.

Is this an area of potential agreement between the original article authors and critics?



  1. McIntyre/McKitrick were "pushing back on a single paper at the cutting edge of new research" too, but Mann stonewalled them for so long that the MBH became "established knowledge" (via other papers being based on the same flawed premises) before it could be effectively criticized. If Mann&co had been upfront and open and willing to admit errors when first pointed out, a lot of the unpleasantness of the climate debate could have been avoided.

    In this case, the arsenic hypothesis is so new that almost nobody yet has significant reputational capital invested in it. So it's no wonder people are willing to entertain criticism. It also helps that there aren't any billion dollar industries (like carbon trading) riding on the results.

  2. PCA wasn't the best choice, all the rest of M&M was useless.

    And proxy results are just one part of the overall climate change paradigm. It hasn't been overturned.

  3. So you don't think the issues related to the proxies were useful? The knowledge that all the studies were using the same outdated versions of a few proxies when newer versions were available...but showed different results? The knowledge that data was arbitrarily excluded based on not producing the right conclusion? M&M eventually showed that you can *get* a flat-shafted hockey stick by picking and choosing your data sources but that other choices - equally or more justifiable - give us back the MWP and LIA as significant features. Comparing like data types to like and excluding those that aren't good temperature proxies, a proxy-only reconstruction with decent error bands now suggests it was about as warm during the MWP as it is today. That might not overturn "the overall climate change paradigm", but it does overturn one tiny part of it - one link in the chain of argument for alarmism.

  4. On further reflection the biggest contribution of M&M has nothing to do with the specific issues under debate - PCA or Graybill/Ababneh's bristlecone pines or what-have-you - but is the fact that they got journals to fix their policies regarding data availability. There was a surprising amount of resistance to the idea that studies published in Nature should be replicable in the sense of examining the actual data published. As opposed to replicable in the sense of you can only see this data if the study author likes the conclusions he thinks you're likely to reach, but if you go collect your own data and do your own study it might (or might not) reach a vaguely similar publishable result.

    Basically, McIntyre and his fans stormed in with an engineering/quality-assurance/open-source perspective where it wasn't wanted and eventually - after much debate and a couple of congressional investigations - won the day. The newer policies at Nature, at CRU and elsewhere should help science reach solid conclusions faster than it otherwise would. Whether or not you think Mann's conclusions are solid, the fact that you can *test* them now without a ten-year fight to see what he's doing is a huge improvement. Despite all the sniggly little issues with Mann's later studies, they are just infinitely better than MBH98/99 in that regard. And probably wouldn't have been prior to this fight.

  5. I agree with you Glen on increased data availability, while understanding the reluctance by climatologists to deal with people who requested it in bad faith.

  6. FWIW, the issue with the arsenic paper is pretty much what the issue with the Mars meteorite paper: Both take something amazing and push it too like light years too far in order to support NASA goals

    In the case of the Mars meteorite, it is truly amazing that they found and identified a meteorite from Mars, but the claims of "this proves that there was life on Mars" (we could discuss details) were not supported by the evidence. Given enough sensitivity, you can find organics in Hell.

    In the case of the arsenic "life form" the fact that the bacteria could survive in such a hostile environment is huge, but the claim that they bacteria had substituted arsenic for phosphorous is crap based on the evidence they presented.


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