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- 1 'Competition' vs. 'Predation' ?
- 2 Untitled
- 3 Answer
- 4 Lead sentence needs attribution
- 5 Rock Life?
- 6 Fix it
- 7 Fossil?
- 8 Dating and oxygen
- 9 Importance
- 10 Misconception
- 11 Who cop[i]ed who?
- 12 Tells
- 13 Cryptozoon
- 14 Ernst Kalkowsky
- 15 Places where found
- 16 "Time lapse photography of modern stromatolite formation"
- 17 3.7 by stromatolites? "not as clear cut [evidence] as you’d ideally want for such an extraordinary claim"
'Competition' vs. 'Predation' ?
According to reference #8, stromatolites reached "peak diversity 1 to 1.3 billion years ago... then declined to about 75% of this level between 1 billion and 700 million years ago, dropping to less than 20% at the beginning of the Cambrian", i.e. 550 million years ago. A decline in diversity is characteristic of competition, e.g. emergence of stationary multi-cellular Eurkarya sea-weeds, c.1000 Mya. A drop in diversity is characteristic of predation, e.g. emergence of mobile multi-cellular Bilateran macro-predators, c.600 Mya. 188.8.131.52 (talk) 00:27, 26 November 2011 (UTC)
Quoting from the article: "The Precambrian atmosphere was rich in carbon dioxide, but lacking in oxygen necessary to sustain more complex multicelluar life."
What does this mean? I checked the Precambrian page and found no information. I'm curious why oxygen is considered necessary for complex multicelluar life.
The reason oxygen is essential for complex multi-cellular life is the fact that oxygen is essential for respiration which in turn sustains life and therefore without substantial oxygen, life could not exist. (complex multi-cellular organisms are all forms with more than one cell).
- Respiration with oxygen also gives more energy than other kinds of metabolisms that have been found on Earth.--BrendanRyan 03:31, 1 August 2005 (UTC)
Lead sentence needs attribution
The opening sentence of this article reads:
Stromatolites (from Greek strōma, mattress, bed, stratum, and lithos, rock) are defined as "attached, lithified sedimentary growth structures, accretionary away from a point or limited surface of initiation".
I'm not comfortable with the "are defined as" in this. Who defines them this way? I'm a bit concerned that the author doesn't entirely understand the definition and is just copying from an unidentified reference work. I certainly don't understand it, but I'm not a biologist.
I also wonder if there isn't a more vernacular definition that might be of use to the general reader.
- I came to this page to make the same argument; the first sentence should be a summary of what stromatolites are, not a quote of a particular source (and a distracting etymmology embedded). Will come back to this... battery... dying... :) --babbage (talk) 00:26, 19 February 2008 (UTC)
The article seems to suggest that these are infact living creatures. How could this be? Is it some sort of golem? How does it feed? The article doesn't seem to give enough information. Of course it might, but i'm only fourteen so my understanding of word with over 5 letters is dim.
An answer: Stromatolites are living organisms... The yellow and red slime in Yellowstone hot pools are living stromatolites as are the Shark Bay living specimens. Minnesota, Wisconsin, Colorado, Washington and Oregon all have recently discovered colonies growing. It feeds by water absorbtion of minerals and by photosynthisis from sunlight. The waste from many is lime, see the second Shark Bay picture with the white powder on the specimens? Stromatolite waste. Stromatolites with heads have a consistancy of cottage cheese. The article eludes to books, the books are the clue. One doesn't learn microbiology on a google search... (adv. removed)
- Removed blatant ebay advertizing from above post. Vsmith 12:05, 8 December 2006 (UTC)
Actually, stromatolites are the deposits left behind by the living organisms, not the creatures, themselves. The actual organisms that produce the structures are called cyanobacteria. Stromatolites are basically trace fossils, that is, fossilized remains not of the organism itself, but of what the organism left behind, such as footprints, burrows, eggshells, and coprolites (fossilized...er...poop).
I'm gonna be really honest, this article sucks. It sounds like it was written by someone who knew no more about stromatalites than what he had learned in the last five minutes from Google. Someone should fix this. —The preceding unsigned comment was added by 184.108.40.206 (talk) 23:28, 20 January 2007 (UTC).
The second paragraph in the section "Fossil Record" says: "Stromatolites are a major constituent of the fossil record for about the first 3.5 billion years of life on earth..." The length of this period needs to be documented or clarified, especially since we're not particularly clear when life actually arose. The Abiogenesis article says life is likely to have arisen some time between 4.4 bya and 2.7 bya, and mentions relatively recent evidence the earliest stromatolites appeared 3.5 bya. Even if the latter is true, why distinguish the *first* 3.5 billion years of life on earth from any other period of life on earth? -- Badlermd 21:31, 24 July 2008 (UTC)
May this article can stay better in sedimentary rocks. Not all stromatolites are sure from organic source, also the article states the modern stromatolites are far different from the precambian ones. --Demostene119 20:36, 20 March 2007 (UTC)
Dating and oxygen
I found this article confusing in important respects. It states that multi-cellular life could not emerge until the Cambrian due to the lack of oxygen, but the article 'Oxygen Catastrophe' dates atmospheric oxygen - poisonous to early life - to 2.4 billion years ago. In addition, the Ediciarans came before the Cambrian and they were complex and required oxygen.
The article does not give the information I was searching for when I read the article - when stromatolites emerged. As they are still extant, do they not require oxygen, or were the early stromatolites different in that respect? Dudleymiles (talk) 20:47, 11 February 2008 (UTC)
- Good points, this article needs updating. See Evolutionary history of life for useful info and references about oxygen and about the earliest multi-cellular life.
- Stromatolites are still extant. What's confusing is that stromatolites are not organisms, they're structures built by organisms, and there's no guarantee that 2 stromatolites in different places are built by similar sets of organisms - rather like the fact that many types of animal build nests.
- As for oxygen and the early stromatolites, there are a few possibilities - see Microbial mat. -- Philcha (talk) 21:57, 22 October 2008 (UTC)
- See Microbial mat, of which stromatolites are a special case. I'll add a "further info" tag at the top for now. -- Philcha (talk) 21:49, 22 October 2008 (UTC)
Reply; See the DVD/movie "How the Earth was Made". About 20 minutes in to the movie is a nice study of Stromatolites and their significance; to quote one of the scientists "(they)are the producers of most of earths' oxygen. They are likely to be the 1st (photosynthetic) life forms on earth. They are all of our great-great-great-great (ad infinitum) grandparents". Charming analogy. Robecology. — Preceding unsigned comment added by Robecology (talk • contribs) 16:16, 24 January 2014 (UTC)
There is a widely held misconception that plants photosynthesize in order make food. While this is true, plants also use CO2 to make their own structure. Most of the public does not realize that, for example, a redwood tree is largely made of carbon from C02 manufactured during photosynthesis. In the section on the fossil record, the statement is made that cyanobacteria photosynthesize to make their food. While this may seem petty, I think it is something we need to be careful about. —Preceding unsigned comment added by Vdeneroff (talk • contribs) 21:32, 22 October 2008 (UTC)
- Depends on how you define "food". Strictly speaking plants and cyanobacteria photosynthesize water and CO2 to produce energy (sugar, later converted to ATP), some of which they use to build structural components, which in plants are largely made of more water and CO2. -- Philcha (talk) 22:02, 22 October 2008 (UTC)
Who cop[i]ed who?
http://www.absoluteastronomy.com/topics/Stromatolite Khullah (talk) 01:17, 20 October 2009 (UTC)
I've found some old references discussing the term "cryptozoon" (with reference to the Warrior Formation), and I think this old term is out of usage and is replaced with "stromatolite". Can anyone confirm this with an external reference? It would be good to clarify this in this article. Jstuby (talk) 20:42, 6 March 2011 (UTC)
Places where found
The article mentions several locations, but omits an important one - in the gypsum lakes of Innes National Park at the tip of Yorke Peninsula, South Australia. According to the South Australian state Department of Environment and Natural Resources brochure on Innes National Park, this is one of only three locations in the world where they are found in that particular form. I am not knowledgeable about these details, but i feel it rates a mention. Ptilinopus (talk) 07:08, 15 December 2011 (UTC)
"Time lapse photography of modern stromatolite formation"
It's mentioned how fruitful it's been to view stromatolites forming and existing with time lapse photography, but there's not a video link (or a citation). Wikipedia can be such a tease sometimes! Does anybody know where I could see such a video? I had no luck searching elsewhere. It would be a great illustration, both for my sake and other readers. Thanks. Vincentvanguard (talk) 02:25, 7 June 2014 (UTC)
@Vincentvanguard: I've just expanded the section describing the Time lapse photography. The relevant journal article, or rather the only one I could find that fits the description mentioned on the page, has permalinks to YouTube videos showing things like cyanobacteria moving toward light sources and also traveling across a piece of graph paper--very interesting! The gist of the article is now fleshed out on the page. I wanted to make links to the videos, but it seems YouTube links are banned from Wikipedia. Mjh2016 (talk) 17:25, 1 September 2016 (UTC)
3.7 by stromatolites? "not as clear cut [evidence] as you’d ideally want for such an extraordinary claim"
This claim needs to be treated skeptically. See\this WaPo article, which quotes rxns from uninvolved scientists:
- The multiple lines of evidence for the Greenland stromatolites "are not as clear cut as you’d ideally want for such an extraordinary claim," cautioned Abigail Allwood, a geologist at the NASA Jet Propulsion Laboratory who has studied fossil stromatolites.