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2800 year old microbes

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This could probably be explained better. I'm pretty sure that the microbes are not individually 2800 years old - how could we tell anyway? More likely, this is the period of time that the lake has been isolated from the atmosphere and the outside world at large. But I'm no expert to say the least, so I'd rather not change it until others have had a chance to comment. Cheers, --Plumbago 08:57, 3 July 2006 (UTC)[reply]

Your comment sounded logical, until I surfed to the National Geographic External link that explained the age. Apparently the microbes are frozen in the single cell equivalent of suspended animation. When the ice melted, the the wee beasties came back to life. Revmachine21 11:23, 3 July 2006 (UTC)[reply]
Yup, I'd buy that. Although I thought it was still a liquid lake under solid ice? Such that the microbes in question were happily living in the liquid water. If they were living in the ice above the lake, that's not clear. Either way, the reference to the microbes and their age is unclear in the current article. Cheers, --Plumbago 11:33, 3 July 2006 (UTC)[reply]
I've now read the NG reference properly. So they are in the ice, but frozen solid. I wonder if anything lives in the lake? Anyway, I'll try to edit the article to better reflect this. Cheers (again), --Plumbago 11:37, 3 July 2006 (UTC)[reply]
I've added in a bunch of external links for future research on this lake. Due to unique properties, the article deserves some non-standard sections. Anyway, there are a lot of details about the reasons for the longevity of the wee beasties (sedimentation above blocking light). I've done some research to add in the InfoBox components. If you could continue the research on the areas I was unable to find some data. Next step adding in an actual outline... Revmachine21 14:33, 3 July 2006 (UTC)[reply]

Notoriety?

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Hi there Revmachine21. Nice work on the article! It's looking really good. I did just want to query one thing though - did you really mean "notoriety"? Surely it'd be better to say the lake was notable. I can't quite see how the discovery of 2800 year old microbes makes it notorious. Unless they later turned out to be faked or something. Keep up the good work! Cheers, --Plumbago 17:00, 4 July 2006 (UTC)[reply]

Noted, reworded & thanks! If you can think of a better phrase, I welcome the assistance. Revmachine21 04:45, 5 July 2006 (UTC)[reply]

Moving relevant info from Revmachine21 talk page

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Hi Revmachine21. Further to your good work on Lake Vida, I thought you might be interested in the following scientific papers on the subject (I found 3 from a brief search). I've given the full references below together with their abstracts.

  • Doran PT, Fritsen CH, McKay CP, et al. (2003) "Formation and character of an ancient 19-m ice cover and underlying trapped brine in an "ice-sealed" east Antarctic lake" PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 100, 26-31.
Lake Vida, one of the largest lakes in the McMurdo Dry Valleys of Antarctica, was previously believed to be shallow (<10 m) and frozen to its bed year-round. New ice-core analysis and temperature data show that beneath 19 m of ice is a water column composed of a NaCl brine with a salinity seven times that of seawater that remains liquid below -10degreesC. The ice cover thickens at both its base and surface, sealing concentrated brine beneath. The ice cover is stabilized by a negative feedback between ice growth and the freezing-point depression of the brine. The ice cover contains frozen microbial mats throughout that are viable after thawing and has a history that extends to at least 2,800 C-14 years B.P., suggesting that the brine has been isolated from the atmosphere for as long. To our knowledge, Lake Vida has the thickest subaerial lake ice cover recorded and may represent a previously undiscovered end-member lacustrine ecosystem on Earth.
  • Hall BL, Henderson GM (2001) "Use of uranium-thorium dating to determine past C-14 reservoir effects in lakes: examples from Antarctica" EARTH AND PLANETARY SCIENCE LETTERS 193, 565-577.
The chronologies of many lacustrine records suffer from radiocarbon reservoir effects due to the presence of dissolved 'dead' carbon or to slow air-water exchange. Here we use the TIMS uranium-thorium disequilibrium method, in conjunction with AMS radiocarbon dating, to determine the age of lacustrine carbonates and to quantify the past radiocarbon reservoir effect in two Antarctic lakes with differing characteristics. By correcting a single-sample U/Th age for detrital contamination, a C-14 offset of similar to 18000 yr was obtained for carbonates from the former grounding line of the Ross Sea ice sheet in Glacial Lake Trowbridge. This large reservoir effect is believed to result from the direct input of old CO2 from glacial meltwater. In the second example, an isochron approach on coeval samples formed at the bottom of Lake Vida (now exposed due to lower lake level) yielded an age of 9550 +/- 340 yr B.P. and a radiocarbon reservoir age of 3600 yr. This offset was probably the result of lack of aeration due to perennial ice cover and/or strong density stratification. This evidence for long-term isolation of the lake bottom indicates another level of hardship for life in the Dry Valley lacustrine environment - an environment studied as an analogue for extreme periods of Earth history, as well as for exobiological implications. The success of the U/Th technique on these two examples indicates that TIMS U/Th dating will be of widespread use in dating the important climate information recorded in the Dry Valleys both within and beyond the C-14 age range. (C) 2001 Elsevier Science B.V. All rights reserved.
  • Fritsen CH, Grue AM, Priscu JC (2000) "Distribution of organic carbon and nitrogen in surface soils in the McMurdo Dry Valleys, Antarctica" POLAR BIOLOGY 23, 121-128.
The organic carbon and nitrogen contents of sediments in the upper 2 cm of the soils surrounding several lakes in the McMurdo Dry Valleys were measured in a relatively high-density sampling grid, in order to better understand the present-day distribution of organic matter in the ecosystem that is most readily transportable via aeolean processes. Carbon and nitrogen contents of the bulk sediments and size-differentiated sediments decreased in a series according to lake basins oriented along the Taylor Valley's main axis (Lake Fryxell > Hoare greater than or equal to west lobe Bonney greater than or equal to east lobe Bonney). Samples were also obtained around Lake Vida and showed this basin to contain less organic matter than those in the Taylor Valley. This regional spatial analysis supports the emerging view that each basin provides distinct environments for in situ microbial activity, lithogenic weathering, aeolian deposition and sorting that can be detected through synoptic sampling.

There are probably more out there (certainly these three are cited by other papers), but I've not tried to dig them up yet. I thought there might be something in these that would help with your work on the article. Best regards, --Plumbago 13:52, 5 July 2006 (UTC)[reply]


Moving relevant info from Plumbago talk page

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Thanks Plumbago... I appreciate the research assistance. I'm finding things slowly but I'm digging up interesting stuff (did you know Antarctica has its own domain name .aq? Can't be used for the article, but I'll add that to the bank of useless information I know). I'll slowly enrich the text aiming for a new paragraph per day.

One thing you can help with is the editing. I stink at it under the best circumstances, and after a 12 hour work day, 1.5 hours in the gym, not much brain power is left for spelling & grammar.  :-) Revmachine21 13:58, 5 July 2006 (UTC)[reply]

I just finished up the geology section and I'm not terribly happy with it. Could you take a quick look and let me know what you think? If you think it sucks, I'll take a 2nd stab. Revmachine21 13:48, 6 July 2006 (UTC)[reply]
Hi there. I've had a quick look and my main comment would be that there are a number of lists there that seem somewhat unrelated to Lake Vida itself. While an overview of the kinds of geological features around the lake seems reasonable to me, the names, etc. of specific features seem less useful. Unfortunately that would truncate the geology section somewhat, but it sounds like we have only limited data to work from. Another comment, in the infobox I'd replace "undeterminable" with "unknown" or "undefined". At the moment it sounds like it's not possible, in principle, to work out the depth of the lake. Also, I think the economy section could probably be filled in ("none").
I've tried to track down any information about this chap Kite, but can't find any appropriate references to meteorites, Antarctica or the surname Kite on the Web of Knowledge (a UK science publications resource, like PubMed). He might be finding meteorites while doing other research though I suppose. I have, however, tracked down a 360° panorama from Lake Vida's Met. Station. It's quite good actually, and I've added it to the reference section. Regarding which, the Reference section needs to be linked into the article a bit better at present (use of <ref>, etc.).
Anyway, sorry if it sounds like I'm just giving you tasks! I'll try to work on it a bit myself, but I may not have the time. Cheers, --Plumbago 16:57, 6 July 2006 (UTC)[reply]
No worries! You've kind of validated a general unhappiness I had with the info I put together under the geology section last night at 11PM. I will give a think to how to rework it. Regarding the "Undeterminable" comment, I didn't use "Unknown" or "Undefined" for a specific reason. The high salinity actually prevents measurement of depth using sonor. Something I ought to mention maybe in the Hydrology section? I found reference to Mr. Kite during my research. Was only a sentence or two, but definitely there, if memory serves, I've got it linked under the reference section. Will double check tonight. Anyway, that's in an upcoming section and I will flesh this detail out in future versions. Good find on the panorama shot. Onto the references section, I know a bit of a mess. Was planning to tackle that when I complete the other sections. Never actually set this up before in previous wiki articles (I know, bad form and all) and need to figure it out. When I get farther along I will give a shout for a courtesy edit.
Thanks so much. Revmachine21 00:02, 7 July 2006 (UTC)[reply]


To do list

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Tried to find the lake on Google Earth, but no joy there. (But I did find my car parked outside my house!) --Plumbago 12:31, 10 July 2006 (UTC)[reply]

Completed Tasks

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  • Classify species by major taxonomic divisions : e.g. prokaryotes/eukaryotes, algae/plants, protists/metazoans, etc. (for instance, at the moment "microbe" list includes protists and metazoans) --Plumbago 08:09, 8 July 2006 (UTC)[reply]
Can we specify more precisely what you mean using an example on the list, Acanthocystis sp? Per the Austrailian Antartic website, they have the following break down, to which level of detail do you think is a good addition?
Kingdom - Animalia
Phylum - Sarcomastigophora
Class - Unknown
Order - Heliozoida
Family - Unknown
Genus - Acanthocystis Revmachine21 08:01, 8 July 2006 (UTC)[reply]
Hi again. I don't think we need to get too much into the detailed taxonomy, just some split into large groups such as bacteria (maybe eu- or archae- if we have to), algae, plants (if there are any there), "animal" protistans, metazoans. Acanthocystis would be protista in this grouping. At the moment it's listed as a microbe so might be confused with bacteria. Anyway, just a suggestion. The article's looking really good now. Nice work. --Plumbago 08:09, 8 July 2006 (UTC)[reply]
You know, I'm going to have to ask for your help here. I already checked the wiki links for the fauna & flora names and you can see there weren't many existing articles. I'm an investment banker and my high school biology days are long behind me! I really appreciate the nice comment and your editing help here. Once we get these to do items behind us, maybe we can put the article forward for good article / feature status. Revmachine21 08:37, 8 July 2006 (UTC)[reply]

Species list

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"Microbes"

  • Acanthocystis sp. : protozoan, Sarcomastigophora
  • Actinophyrys sp.  : no WS entry, AADC say Sarcomastigophora, so protozoan
  • Alloptes stercorarii (Common name Mite) : no WS entry; but mites are arthropods, so metazoans
  • Bodo sp. : no WS entry; but WP link suggests kinetoplastid protozoan
  • Chilodonella sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Epistylis sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Euplotes sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Halteria sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Homalozoon sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Nassula sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Oxytricha sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Philodina spp. : rotifer, so metazoan
  • Pleuronema sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Podophrya sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Pyxidium sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Saprophilus sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Spathidium sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Sphaerophrya sp. : no WS entry, AADC say Ciliophora, so protozoan
  • Tydeus setsukoae : no WS entry, AADC sat Arachnida, so metazoan
  • Unknown sp. (Common name Water bear) : water bears are tardigrades, so metazoan
  • Vorticella sp. : ciliate protozoan

"Algae"

Going through Wikispecies, I've been unable to find most "microbes", and the ones I have found are either protozoans or metazoans (i.e. big, cuddly eukaryotes). My guess is that the rest are bacteria, so are less well characterised, and less likely to turn up on WS. Much more success with the "algae", although none are actually algae. All (bar one) were bryophytes or hepatophytes (related "primitive" groups). The "one" was a fungus.

Anyway, I'll link to WS where appropriate, and try to reorganise the lists somewhat. Regarding the unknowns we've got listed at the moment, I'll try to find out if there are other taxonomic databases that might help with that. I always hated taxonomy at university, but I've quite enjoyed tracking down the species here. Cheers, --Plumbago 12:07, 10 July 2006 (UTC)[reply]

Second pass. I used the AADC's database from the link on the page. That clears up most of the "unknown" species. Turns out they're almost all ciliates, so protozoans. A bit of a blind spot at WS on this group by the looks of things. Anyway, it means that we can break the current list up into : protists (ciliates, amoebae, etc.), metazoans (various), plants (bryophytes and liverworts) and fungi (single speces). That'll look better I reckon. --Plumbago 12:29, 10 July 2006 (UTC)[reply]
Thanks Plumbago, I've busted up my hand a bit am going to give the article a rest for a few days to recuperate. Once back, I'll tackle the rewording for this.

No worries. Hope your hand heals quickly. In the meantime, I'll assemble alternative lists of the species below. These can be ported into the main article if you think they're up to it. All of the species you listed before are Domain Eukaryota, but there are representatives from each of the four component Kingdoms, so I've broken the two lists along these four lines :

Kingdom Animalia

Kingdom Fungi

Kingdom Plantae

Kingdom Protista

They're a little bit of a mess because they include links from both WP and WS. Although most appear on WS, some also occur on WP, and I've preferred WP over WS where possible (reasoning that the latter is a "different" site). The lists could perhaps be put into some sort of table structure to make them clearer. I can't work out how best to do this though - my HTML and LaTeX background doesn't help me much in WP. Anyway, I hope this helps somewhat. Cheers, --Plumbago 12:30, 11 July 2006 (UTC)[reply]

Nicely done Plumbago. Hand is better but still taking a break from any serios typing.


Lake Vida has been buried

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http://www.nasa.gov/vision/universe/solarsystem/0422mars.html Above: Antarctica's Lake Vida has been buried under 19 m of Antarctic ice and gravel for over 2,500 years, existing as liquid only because of its high salt content. Within a few meters of drilling, scientists found frozen microbes, supporting the idea that similar microorganisms could be found in frozen brine beneath the Martian surface. Here, a robot meteorological station monitors surface conditions. (More) Credit: Thomas Nylen & Andrew Fountain (PSU), NASA, NSF--Tamás Kádár 21:44, 23 May 2007 (UTC)[reply]


Class change

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After reviewing the standards for project classes, I'm bumping this article up. If anybody disagrees, please provide details why you've downgraded in order to address those specific gaps.

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