Talk:Felisa Wolfe-Simon

Initial comments

Wolfe-Simon will announce that there are microorganisms in Lake Mono which use arsenic in their DNA instead of phosphor. <-- This is interesting "news", but no source is provided for this revelation. If the source is someone who has seen the soon-to-be-published article then public discussion of the results reported in the article seems to be a violation of the existing restrictions imposed by the publishing journal. In about an hour we should have confirmation. --JWSchmidt (talk) 18:06, 2 December 2010 (UTC)

If you search Google News for "arsenic DNA", you can see there are already a number of sources that essentially broke the embargo and published early. Though you are right that the full details will be available soon. Dragons flight (talk) 18:14, 2 December 2010 (UTC)

No. No, no, no. Most of the "sources" on google are either framing the DNA arsenic as a POTENTIAL and a POSSIBILITY, or are simply making groundless assertions. Most people do not understand the role of phosphorous in DNA, so they certainly do not understand the potential role of arsenic in DNA, quite aside from the fact that there's no proof that any FUNCTIONAL DNA is utilizing arsenic. Please get an education. —Preceding unsigned comment added by 216.254.111.34 (talk) 20:12, 2 December 2010 (UTC)

Born

When was she born? 212.186.24.212 (talk) 20:44, 2 December 2010 (UTC)

Picture & NASA announcement External Link

http://www.nasa.gov/images/content/503354main_Wolfe_Simon.jpg at http://www.nasa.gov/topics/universe/features/astrobiology_toxic_chemical.html# Unfortunately I'm no good with wiki formatting and pictures as I looked for and didn't find an editing button that said "add picture to this article". Please help the technologically challenged Neanderthal. Thank you. Pär Larsson (talk) 19:40, 2 December 2010 (UTC)

Notability?

As it reads, this article and the linked articles resemble more to an auto-promotion for an early career scientist (i.e., a link to her CV and self-references). If it is intended to be a biography, maybe explain to the reader why she is outstanding with respect to the peers in the field. While she got good media coverage in the past few days, she is far less well known than, say, most of the senior colleagues that co-authored her work. Yet, the latter don't have a Wikipedia page. Maybe this news (today's press conference) should be place in a broader context along with her peer's research. 74.176.250.114 (talk) 00:53, 3 December 2010 (UTC)

Sometimes one really big discovery is enough for an academic (per WP:PROF: "the person has ... made a significant discovery or solved a major problem in their academic discipline"). She made a discovery that (unless somehow disproven) will probably have a more lasting impact on microbiology than the entire careers of many microbiologists. Likewise her exposure in the popular press is probably now greater than many (though probably not all) of her coauthors. Yes, the article can be improved, but I see no problem considering her notable. I also would say that WP:BLP1E doesn't apply since academics aren't "low profile individuals" and her public contributions have been and (presumably will be) ongoing. She had already won significant awards and done significant work. By itself, that wouldn't have earned her a place here, but in combination with a major discovery it certainly does.

CNN and BBC both carried interviews with her yesterday and today, on television and the web. I think that qualifies her as notable.--Atikokan (talk) 21:56, 3 December 2010 (UTC)

Of course the article can still be improved to be more comprehensive and less focused on a single event, but that's an editorial problem not an inclusion problem. Dragons flight (talk) 01:30, 3 December 2010 (UTC)

One could argue that this is not a major discovery, just a well-hyped one. Breeding bacteria is not the same as discovering a native species that can do the thing naturally. And which awards are significant? Abductive (reasoning) 01:52, 3 December 2010 (UTC)

I'm not sure what distinction you mean by "naturally". You take this bug and put it in arsenic without phosphate and it goes to town, that seems to say it is a natural part of its abilities. Even if it were somehow "man-made", it would still be amazing for a bug to be capable of living without phosphorus. As for awards, we aren't talking about Nobel prizes, but there are only about ~30 NSF postdoctoral fellows awarded in biology each year, and only ~100 Kavli fellows per year across all disciplines. Both of which place her in the top tier of early career scientists. For a point of comparison the US issues about 45000 PhDs per year. Dragons flight (talk) 02:07, 3 December 2010 (UTC)

It doesn't live without any phosphorus. I personally know many NSF postdoctoral fellows in biology; as post-docs, they are not professors and are generally average scientists. This Kavli fellowship is a funding thing, right? Abductive (reasoning) 02:11, 3 December 2010 (UTC)

Actually we don't know if it can live without any phosphorus, because they couldn't yet exclude all phosphorus from the sample, but it lives with much less phosphorus than should be possible given the amount expected for its DNA and other processes.

Be careful, having a postdoc that is funded by the NSF (e.g. through a PI's grant) is different from an NSF postdoctoral fellowship. The latter is significantly rarer and more prestigious. The Kavli is meant to support the best young minds through networking and community. They organize a conference and provide travel expenses for 50-100 of the best early career scientists, but I don't believe there is any ongoing support in the typical case. (Though the Kavli Foundation does have a separate set of grants, unconnected with the NAS Kavli Program.) Dragons flight (talk) 02:23, 3 December 2010 (UTC)

Again, extremophiles do all kinds of extreme stuff. There's a reason they couldn't exclude all the phosphorus; the critters need it to live. I know the difference between being funded through a PI and an NSF post-doc. I doubt that a scientist would be kept at AfD for being invited to a conference designed to "support the best young minds through networking and community". In fact, that sounds lame. This gal's career is set, but there is not a single secondary source that analyzes her as a topic. Abductive (reasoning) 02:30, 3 December 2010 (UTC)

You do realize that we are talking about a bug that apparently can use arsenate in place of phosphate in its DNA and proteins, right? That's a big deal. This isn't just about finding an arsenic tolerant bug (which would be fairly routine), it's about finding a bug that embraces arsenic as a total replacement to phosphorus in apparently a very fundamental and unexpected way. Dragons flight (talk) 02:33, 3 December 2010 (UTC)

For the records, I agree the awards and other things - by themselves - would never be enough to survive AFD. But I also think you are significantly underappreciating how unusual her discovery is. Dragons flight (talk) 02:36, 3 December 2010 (UTC)

Felisa is perhaps better known in some scientific circles for her self-promotion. I am wondering whether she didn't create this article herself, honestly. I have no doubt her self promotion will continue as unabated as her career, but as for now, I do not believe that this discovery warrants a Wikipedia entry let alone a biography of one of the discoverers. —Preceding unsigned comment added by 71.23.216.229 (talk) 03:49, 3 December 2010 (UTC)

I think the point is that this biography is probably a little bit self-serving and could instead be combined with a page dedicated to the scientific topic of astrobiology. Also, saying "a bug that embraces arsenic as a total replacement to phosphorus" is an overstatement. Approx. 10% of phosphorus was replaced by arsenic in the study. As mentioned by Benner in the press conference, the body of evidence is not entirely there yet. Vitriol96 (talk) 04:22, 3 December 2010 (UTC)

The cells were 0.54 +/- 0.21% phosphorous under normal growth conditions and 0.019 +/- 0.0009 % phosphorous under arsenic rich conditions. That's a 97% reduction in my world. Dragons flight (talk) 04:31, 3 December 2010 (UTC)

How much of that is slack? In other words, if I bred bacteria on media with just enough phosphorus to survive and divide, could the level of phosphorus be reduced that far? I'll bet it could. Adding arsenic may be an example of not using the proper scientific control on all the variables. Abductive (reasoning) 08:55, 3 December 2010 (UTC)

No, you couldn't. Based on the number of base pairs, you'd need about 0.02% for the DNA alone. There wouldn't be any phosphorus left for anything else such as ATP, NADH, and protein, which are by far the dominant uses of phosphorus under normal conditions. You seem to want to reject the result without bothering to understand it. In addition to the quantitative considerations, which are pretty compelling, they have direct evidence of arsenate incorporation into both proteins and DNA. Dragons flight (talk) 09:57, 3 December 2010 (UTC)

Rejecting the result without bothering to understand it would be unscientific, and you need to assume good faith. I really want to know how much is slack. I don't have access to the paper. Abductive (reasoning) 11:19, 3 December 2010 (UTC)

Chemistry of arsenates

From the article: "One of the reasons this result is unexpected is because arsenate is generally unstable in water, with a half-life measured in minutes." Does this mean something like, "Chemical bonds between carbon atoms and arsenate groups are generally unstable in water"? Can someone cite some references? --JWSchmidt (talk) 01:27, 3 December 2010 (UTC)

From the journal article: "AsO4 esters are predicted to be orders of magnitude less stable than PO4 esters, at least for simple molecules". The line you quote is based on the press conference (possibly somewhat garbled) where one of the panelists indicated that he had expected arsenate based DNA would be unstable and break down with a half-life "like 10 minutes". Dragons flight (talk) 01:47, 3 December 2010 (UTC)

There are interesting hits on http://www.google.com/#q=arsenate+hydrolysis but if DNA is the main focus then you might consider it a mismatch.

• Synthesis and Hydrolysis of ADP-Arsenate by Beef Heart Submitochondrial Particles] THE JOURNAL OF BIOLOGICAL CHEMISTRY Vol. 258, No. 10. Issue of May 25, pp. 6266-6271, 1983
  • "The first order rate constant for ADP-arsenate hydrolysis at pH 7.5, 30 C, was determined to be greater than 5 min-1 and was estimated to be 70 min-1."
• Kinetics of the hydrolysis of arsenate(V) triesters Inorg. Chem., (March) 1981, 20 (3), pp 905–907 doi:10.1021/ic50217a052
  • "The hydrolysis of trimethyl arsenate in methanol solution was first order in ester and in water with k1(25C) = 73 M-1 s-1, delta enthalpy of 13 +/- 1 kJ mol-1 and delta entropy of -167 +/- 13 J mol-1 K-1. Hydrolysis rates of the esters decreased in the order methyl > ethyl > n-pentyl > isopropyl. An associative mechanism is proposed."

Again, nothing yet with DNA.--Sharonmil (talk) 03:31, 3 December 2010 (UTC)

Doesn't this rate of decay depend very heavily on the pH? Abductive (reasoning) 11:22, 3 December 2010 (UTC)

Right! Most of the hydrolysis is either base or acid catalysed.--13:24, 3 December 2010 (UTC)

BBC coverage

The BBC has povided some covergae of her work here http://www.bbc.co.uk/news/science-environment-11886943 Arsenic-loving bacteria may help in hunt for alien life ny Jason Palmer, BBC News Dec 2 -Best wishes, (Msrasnw (talk) 11:13, 3 December 2010 (UTC))