Talk:Diatom/Archive 1

Archive 1

Genome

user:Petaholmes added this material to the article:

The full genome sequence of saltwater diatom Thalassiosira pseudonana shows that diatoms have a complex evolutionary histroy. Like other early microbes, diatoms seem to have acquired new genes by engulfing microbial neighbors. Perhaps the most significant acquisition was an algal cell, which provided the diatom with photosynthetic machinery. As a result diatoms are left with what appears to be a mix of plant and animal DNA.

Reference: Armbrust el al. (2004). The Genome of the Diatom Thalassiosira Pseudonana: Ecology, Evolution, and Metabolism. Science 306:79-86

Has anyone read this article? Saying they have a mix of plant and animal DNA does not make much sense, since neither diatoms nor their chloroplasts developed from animals, and probably means algae and protozoa. However, the idea that diatoms have a complex evolutionary history including an engulfed algal cell is already well-known, and is something that applies to heterokonts in general so does not really belong here. I've removed this until someone can check the journal, but it looks like this is simply reaffirming the established phylogeny.

The paper says that about a half of diatom proteins have closest homology to plant, red algal and animal (they used mouse sequence data). Genes that were homologous to animal genes had no homology to plant or algal proteins. The paper proposes that animal-like genes may have come from a secondary host, but cannot really say --nixie 23:32, 2 Oct 2004 (UTC)

2 comments

A: The last section was taken from some ancient book, is that OK, or should it be checked, or should the notice be removed?

B: Supposedly they're really nice looking in a microscope, anyone have a pic?

Thanx 68.39.174.150 21:15, 28 Apr 2005 (UTC)

Yup, looks like an old textbook

Yup, I think it's still mostly from a "classic" textbook. Certainly it's big on traditional observational biology. I've not erased it yet, but might get around to this as I gradually change the text paragraph by paragraph.

Agree about the pictures. There are plenty on the web, but we need someone who owns some pictures to put them on.

Here are some pics from the NOAA, Image:Deepwater organic remains from Antartic waters 5-6000m deep.jpg is a historical drawing, and this Image:Diatoms through the microscope.jpg is a photo. Both are good and could both go in the article--nixie 23:07, 28 Apr 2005 (UTC)

Phytoplankton

Whoa—that's a really dense article! How about explain it in terms a layman can understand? How in hell can one write such a long article without ever mentioning phytoplankton?? And how about some external links? For instance, NASA's SeaWIFS? Lupo 07:06, 13 Jun 2005 (UTC)

BTW, SeaWIFS could use some expansion... :-) Lupo 07:06, 13 Jun 2005 (UTC)

OK, point taken. The article could definitely do with some expansion to point readers to more general items on phytoplankton, etc. My fault as I'm responsible for most of the text. That said, I don't think it needs anything on SeaWIFS - that's definitely something for the phytoplankton page (or, better still, the chlorophyll page). SeaWIFS doesn't say anything specific about diatoms, but allows us to infer information about phytoplankton generally. Anyway, I'll try to edit the article over the next few days, but (obviously) have a go yourself if you fancy it. --Plumbago 09:28, 13 Jun 2005 (UTC)

The problem is, I lack the knowledge to do this. I'm no marine biologist! And just to make sure I'm not misunderstood: I'm not asking to dumb the article down. But I think some introductory paragraphs giving the wider picture might help. (BTW, I just happened to stumble upon the article because I have recently read Gregory Benford's Timescape again—that gives you a pretty good idea about my knowledge on diatom! :-) Lupo 10:56, 13 Jun 2005 (UTC)

I think the text was generally good, but I've tried shuffling it so that information on what diatoms are is near the top, and details of how they work is lower down. I've also added some notes on classification. Please take a look and make sure the changes are satisfactory. Josh

Good job Josh. I've made some minor edits to your changes, but I like what you did with the page. You don't, by any chance, have any pictures of diatoms? It's the one major omission on the page (especially since it says how beautiful they are), but I've not got any (legitimate) pictures I could put on. --Plumbago 08:25, 14 Jun 2005 (UTC)

Yup, much better already. What's wrong with the image mentioned above? And is the EO DAAC Study: Polynyas, CO2, and Diatoms in the Southern Ocean a link worth adding to the article? Lupo 13:01, 14 Jun 2005 (UTC)

Thanks! I've added the photo nixie mentioned. The sketch could be useful, too, if the identifications in it are still accurate; but note Dictyocha is not a diatom. I don't have any worthwhile pictures myself - very few of my photos are plankton. I'll let you decide about the link. Josh

That's a nice one! Good choice. I think most (if not all) of the algae one can make out are diatoms. Certainly look that way. --Plumbago 08:46, 15 Jun 2005 (UTC)

Classification

At the moment in the text we say that the heterokonts may be classified as a division (phylum) or as a kingdom. I might be mistaken, but is the kingdom referred to here Chromista? I've already put a reference to this in the main article. However, looking again at the Chromista article, it seems to suggest that the heterokonts are a sub-division rather than a kingdom (e.g. several other major groups are bundled into the Chromista - it's not a heterokont-only party). Could anyone clarify? --Plumbago 11:42, 21 Jun 2005 (UTC)

The heterokonts can be classified as a phylum, kingdom, or something in-between - I'll make the last explicit in the article. As an example, Cavalier-Smith (the main proponent of the Chromista) places the diatoms as follows:

Kingdom Chromista
Subkingdom Chromobionta
Infrakingdom Heterokonta
Superphylum Gyrista
Phylum Ochrophyta
Subphylum Diatomeae

However, other classifications tend to be somewhat different from his. Not everyone accepts the Chromista, and either leave the heterokonts among the Protista or give them their own kingdom (e.g. Heterokonta or Stramenopila). The short story is that the situation is still messy, and not particularly relevant, but I thought a brief note was needed to explain how diatoms could be divided into classes yet listed as a class themselves. If you can make things more transparent, please do. Josh

Thanks for explaining this. I've not a clue about classification at this level. Until earlier today, I'd never heard of the Chromista, so I'm more than happy to leave the whole classification section to you. Keep up the good work! --Plumbago 16:09, 21 Jun 2005 (UTC)

Another question about classification: I was talking to a grad student doing diatom taxonomy this evening, and she (and her advisors) seem pretty certain that diatoms are plants. I don't have a copy of The Diatoms to see what it says, but they still seem protistan to me. - 24 Oct 2006 —The preceding unsigned comment was added by 68.162.84.17 (talk • contribs) .

Your grad student friend may just have been using the word "plant" in the broad sense of autotroph rather than to specifically indicate the evolutionary branch the diatoms belong to. It's clear that they're not Kingdom Plantae just from their photosynthetic machinery - their chloroplasts have a greater number of cell membranes surrounding them indicating an evolutionary pathway distinct from plants (see here). That said, the classification scheme used here (kingdom protista and division heterokontophyta) is not the only one, and it may just be that your friend is being taught by someone who prefers an earlier scheme. Cheers, --Plumbago 08:11, 25 October 2006 (UTC)

Food

What is the diatom food? —Preceding unsigned comment added by 200.73.30.108 (talk) 12:58, 11 October 2007 (UTC)

Diatoms are photosynthetic organisms...in fact some of the most abundant types!

Aren't they made out of glass?

According to this website, they are.

Lunakeet 17:26, 21 May 2008 (UTC)

Well, apparently silicon dioxide (silica) is a component of glass.

Lunakeet 17:28, 21 May 2008 (UTC)

Nanotech

The following was inserted into the "Evolutionary History" section :

In 2005, a team from Georgia Tech, led by Chemical engineer Kenneth Sandhage, has published details of a new process for converting the finely-detailed silica skeletons of diatom into synthetic replicas of materials such as titanium dioxide which conduct electricity and could be used in electronic devices. This development could lead to the genetic modification of diatoms for creation of nano-materials.

I've removed it for now as it clearly doesn't belong in this section (though could be put in an "Applications" section), and doesn't make complete sense. What does it mean to be a "synthetic replica" of titanium dioxide? Is "substitute for" titanium dioxide meant instead? I've no idea, so have removed text to here. Of course, I could just be being stupid ... --Plumbago 17:02, 4 October 2005 (UTC)

P.S. If this has been published, the reference would be good too.

Also there are some early references that Diatom can be used for paint ( http://www.wired.com/science/planetearth/news/2007/10/eco_textiles )

The "synthetic replica" bit definitely sounds odd. It's either titanium dioxide or it isn't. Still, with a rewrite and some better citations, I'm sure it could be a very good addition to the article. 205.175.225.22 (talk) 19:44, 2 January 2008 (UTC)

They start with a natural diatom, and then replicate the shape of the silica shell exactly except using more 'useful' materials. So you end up with something that has the exact shape of the original diatom but is made of arbitrary materials instead of silica. This much was published in Nature. combine this with genetic engineering to modify the structure of the original diaton, and you can end up with very interesting structures made of very useful materials. —Preceding unsigned comment added by 190.22.97.173 (talk) 00:37, 26 June 2008 (UTC)

Number of species

There is a large discrepancy between the number of species in the Diatom article (100 000) and the Heterokonta article (10500), the diatoms are after all a class in phylum heterokonta. The heterokonta is lacking a good reference, but there is not much certainty around the number of diatom species either. Number of diatom species described in articles largely depends on what authors base their guess upon (and species concept), and they are wildly different, ranging from a few thousand species, via 10 000 species suggested by Guillard an Kilham (1977) up to the approximately 200 000 species suggested by D.G. Mann (2004?) at Royal Botanical Garden in Edingurgh, Scottland. So what do we do? At least we should inform about the uncertaity regarding number of species? Rex shock (talk) 11:51, 30 June 2008 (UTC)

Along these same lines, how many diatoms are actually identified, named, classified, etc.? Estimators are professional biologists (?), not professional statisticians, not professional information scientists? At any rate, what is the purpose of the estimates, because certainly estimates have them. Are they to encourage research funding? To estimate biodiversity? Or are they for a purpose as limited, say, as creating factoids for PBS specials? 24.130.17.190 (talk) 09:24, 5 December 2008 (UTC)

Calcareous Diatoms?

This article completely ignores the fact that many diatoms secrete shells of calcium carbonate, which is the primary source of calcareous diatom oozes.Cadwallader (talk) —Preceding undated comment was added at 20:28, 1 February 2009 (UTC).

Have you a reference for that? Did my Ph.D studying lacustrine diatoms and have never found reference to calcium carbonate species, are you sure your not thinking of foraminifera or radiolarians which can be in the same water column as diatoms and drop out to form a diatom rich calcareous ooze - i.e carbonate substrate with silicious diatoms in it. Munse (talk) 12:20, 5 February 2009 (UTC)

I'm with Munse. I'm not aware of any calcareous diatoms. Their use of silica is pretty much a defining feature of the group as I understand it. There are plenty of other phytoplankton and zooplankton that use calcium carbonate, and I can only assume that it's these that are being referred to here, possibly in the manner that Munse suggests. Cheers, --PLUMBAGO 14:12, 5 February 2009 (UTC)

Euk x Prok

'Eukaryotic' algae? Is there any other kind of algae?? --Spmoura (talk) 23:47, 17 May 2010 (UTC)

The term "algae" has also been applied historically to some prokaryotic phototrophs, with the most well-known example being blue-green algae. Technically, the term "algae" is now generally understood to preclude bacteria as well as "higher plants", but the terminology is still sometimes used. One of the remaining problems with the term "algae" is that the eukaryotic groups that fall under it have quite a diverse evolutionary history, so it's debatable whether the term is much use at all. Anyway, I'll alter the use here. Cheers, --PLUMBAGO 16:34, 21 May 2010 (UTC)

Algae or not

The first sentence in the article says diatoms are a major group of algae. The second sentence under 'Aquariums' says they are not algae at all.97.113.84.178 (talk) 14:12, 22 September 2010 (UTC)

The anomalous edits were by a single editor, and introduced other (unsourced) material of questionable quality (cf. "carbon nutrients"). I've rolled back to remove all of this. --PLUMBAGO 14:39, 22 September 2010 (UTC)

Name

Why are they called Diatoms? When I was younger, I thought that was weird because it implied that they were made of only two atoms, which is obviously not the case. Stonemason89 (talk) 04:35, 5 December 2010 (UTC)

It's from the Greek, it means "cut in two" (on-line etymology dictionary), probably because of the two overlapping valves. There's also a company that makes diamond knives for slicing biological tissue (and other things) into sections less than 100nm thick. The company is called "Diatome," and the name is from the same origins. --Kleopatra (talk) 05:09, 5 December 2010 (UTC)

Nano Silica based micro nutrients

We have invented a Nano Silica based micro nutrient powder specifically to grow diatoms. US Patent No. 7585898, Sept 9, 2009. Title "A Composition for growth of Diatom Algae." This used Nano silica to deliver micro nutrients to Diatoms in any type of water.

I had incerted a reference to this invention on the Diatom page but this was deleted, can anyone review the patent and include a suitable reference. --Bhaskarmv (talk) 06:54, 23 January 2011 (UTC)

— Preceding unsigned comment added by Bhaskarmv (talk • contribs) 05:49, 23 January 2011 (UTC) 

It might be helpful if you first explained why this powder is special. Diatoms are not especially difficult to culture using fairly standard laboratory chemicals (I've cultured some myself), so it's unclear what's significant about the powder that you mention. Leaving aside the patent itself, have any scientific publications appeared concerning the diatom growth properties of this powder? They might clarify the use and importance of the powder greatly. --PLUMBAGO 16:26, 23 January 2011 (UTC)

A paper about this product is now available. http://www.degruyter.com/view/j/botm.ahead-of-print/bot-2011-0076/bot-2011-0076.xml?format=INT

We are not culturing Diatoms, we are causing the native Diatoms in large lakes to grow. As you know a lake would have many species, when this powder is mixed into the lake the diatoms consume it and grow rapidly. This is a unique feature. Once Diatoms dominate a lake, the water quality improves.

--Bhaskarmv (talk) 08:46, 23 June 2012 (UTC)

Phytoplankton decline

The new section (orig. titled "Decline in diatom") is based on a paper in Nature. It is a good source, however, the emphasis in the section re: diatoms doesn't appear in the abstract and although perhaps a likely assumption - may be WP:SYN. Does the Nature article make that connection? I don't have access to the full article. Vsmith (talk) 11:58, 23 June 2012 (UTC)

There is ample evidence of Diatom decline in oceans and lakes. The paper cited found that the phytoplankton in higher latitudes declined and increased near equator. This has been referred too in the contribution.

Therefore titling the section 'Diatom decline' is quite suitable.

Dam construction has reduced silt flow down rivers, silt contains silica and micro nutrients. Increase in irrigation has resulted in increase in N and P flow down rivers, this is the reason for increase in other phytoplankton and decline in Diatoms. http://books.google.co.in/books?id=bced7WY0IncC&dq=scope+66+silicon+cycle+v+ittekkot&source=gbs_navlinks_s

--Bhaskarmv (talk) 05:50, 24 June 2012 (UTC)

Again, does the Nature paper discuss or mention diatom decline? Vsmith (talk) 12:38, 24 June 2012 (UTC)

It indicates it and so do many other papers. If you wish I can provide all the links. --Bhaskarmv (talk) 02:40, 25 June 2012 (UTC)

Uses of Diatoms

The uses of Diatoms can be put to has been badly neglected. Diatoms rapidly increase the dissolved oxygen level, they provide good food to fish and consume the nutrients. Diatoms can outcompete all other phytoplankton / algae and keep water clean. Human action has resulted in decline in diatoms and increase in other algae, especially Cyanobacteria and Dinoflagellates (Red Tides). Restoring Diatoms is a very good solution to water pollution.

--Bhaskarmv (talk) 10:47, 21 June 2012 (UTC)

Please refrain from using Wikipedia for commercial promotion. Vsmith (talk) 02:47, 22 June 2012 (UTC)

One of the main reasons for increase in water pollution is the neglect of Diatoms. If the role and importance of Diatoms is recognized and given due recognition then many problems of water pollution can be avoided. Hence a para on the uses of Diatoms should be included on the Diatoms page on wikipedia.

Dr Albert Mann lamented the neglect of Diatoms in 1921 and nothing seems to have changed in over 90 years.

He also wrote about the Economic Importance of Diatoms. http://www.amazon.com/The-Economic-Importance-Of-Diatoms/dp/1169409717

At present Diatoms are only being studied, there is a need to put them to use to solve problems. --Bhaskarmv (talk) 10:46, 22 June 2012 (UTC)

Outdated 1917 books and 1921 quotes aren't really useful here. And please read WP:COI. Vsmith (talk) 22:59, 22 June 2012 (UTC)

The 1917 and 1921 papers are not outdated, they are very much relevant today. I am sure you are aware of the increase in water pollution, algal blooms, fish kills, dead zones, ocean acidification, etc. Diatoms are relevant to all these problems. Hence a section on uses is very much relevant. If the advice of Dr Mann about using Diatom had been followed, the water pollution problem today would have been less that it is.

Please don't delete the entire section without discussion. We can discuss how to edit and improve the content.

There is no conflict of interest. All content is properly supported by good sources.

--Bhaskarmv (talk) 08:39, 23 June 2012 (UTC)

I agree with Vsmith. The material is poorly written and outdated. Suggest you start reworking the text here on the talk page instead. --NeilN ^{talk to me} 08:41, 23 June 2012 (UTC)

If you wish to suggest changes, please do so. Do not just delete the entire section.

--Bhaskarmv (talk) 08:51, 23 June 2012 (UTC)

The entire section is redundant puffery - basically saying that diatoms are an important food source for aquatic organisms. The article already states They are especially important in oceans, where they are estimated to contribute up to 45% of the total oceanic primary production. (although a source is needed for that). We don't need a section entitled "Uses" which says diatoms feed fish and sourced to mostly outdated and poor (WP:RS) refs. Of the references you provide, the The Possible Importance of Silicon in Marine Eutrophication by C. B. Officer and J. H. Ryther is a good source - the others are either outdated, not WP:RS, or simple cherry picking cruft. My suggestion would be to find a source for that relevant unsourced statement in the 'General biology' section and expand on that based on your one good reference in a section perhaps entitled 'Importance in the aquatic food chain' or something akin to that. And stick with relevant, modern reliable sources. Vsmith (talk) 11:36, 23 June 2012 (UTC)

You are not getting the point.

If Diatoms account for 45% of the ocean primary production what is the consequence of this and how can we benefit from this.?

We are not farming lakes and oceans the way we are farming land - why?

If we are to farm lakes and oceans, what should we grow in them?

Water pollution is increasing, this is because Diatoms are not being used though they are omnipresent and very useful and rarely harmful.

The uses section is intended to answer these issues - how to grow more food in lakes and oceans, stop water pollution, etc.

Increasing food production, decreasing CO2 in atmosphere and water and decreasing nutrients in water are three important challenges facing us today. Diatoms are capable of doing all three. This should be mentioned on the Diatom page.

The problem is that research on Diatoms has declined in the past few decades, so there are few recent papers. All research that was required was done long ago and these papers are still relevant. A paper does not become 'outdated' merely because it is old. If this was the criteria then the US constitution and Bible would be called outdated since they are 200 and 2000 years old.

I reject your edit and am reverting the entire section. If you wish to suggest any edits please do so on the talk page and we can discuss them. --Bhaskarmv (talk) 03:13, 24 June 2012 (UTC)

If an editor adds content that is removed by other editors it is normal to try to reach consensus on the talk page before adding it back. The 'Uses' section doesn't appear necessary to me either. Mikenorton (talk) 07:36, 24 June 2012 (UTC)

Oh, but I do "get the point". Bhaskarmv, please read and comply with WP:COI. Your statement here and your efforts here explain quite well your editing on this article. Wikipedia is not here to promote your product. Vsmith (talk) 12:35, 24 June 2012 (UTC)

Diatoms have been neglected over the past 100 years, they can be used but are not being used. Information about this has to be made available on Wikipedia. Please read all the sources I have given and you will understand this. Office and Ryther had clearly stated in 1980 that silica and diatoms should be used to counter eutrophication. The wiki page on Urea clearly mentions uses of urea. The wiki page on Desalination mentions the names of all companies and their technologies and even discusses the costs. Does this amount to promotion of any particular company or technology?

Organic farmers may object to 'promotion' of urea on wikipedia. Clean technology supporters may object to 'promotion' of energy intense desalination technology.

Any genuine view point and technology has to be mentioned on wikipedia, this does not amount to promotion. I understand your prejudice and bias and refuse to accept it.

--Bhaskarmv (talk) 02:38, 25 June 2012 (UTC)

You really do need to engage with other editors here. Your additions are not encyclopaedic in tone and appear to pushing a particular agenda. Mikenorton (talk) 18:08, 26 June 2012 (UTC)

Extremely dense reading

The reading difficulty is discussed above in "Phytoplankton", but the readability is still very challenging. I've been re-reading a college textbook on early life on Earth, and there are still five words in the opening paragraph that I didn't know. The Wikipedia text is dry and fragmented. (The Simple English version isn't an improvement.) The opening paragraphs should supply the basic: Who, What, Why, Where, When. Instead, there's the sentence "Diatoms are producers within the food chain." Lol. What living organism isn't? The important statement comes in the next paragraph, that they are 45% of oceanic production. Even then, I had to look up "primary production" to make sure my guess was right. Then that useful sentence is followed by the quite incomprehensible statement that (spatial, lol) distribution is limited horizontally and vertically. LOL. What the heck is that supposed to mean? I can barely guess, until looking at the footnotes. And even then, again, what living organism isn't restricted in its range?

Really, some conscientious editor needs to use one of the major, standard textbooks as an example of how to introduce this topic, and not drag, the shapes, the valve sizes and monitoring into the first paragraph.

Not to mention, I still, so far, haven't gotten an explanation as to why there are so many types and shapes, which is what I came to learn. Leptus Froggi (talk) 05:56, 7 April 2014 (UTC)

Origin of diatoms

These 2 statement appear contradictory.

From initial description: Fossil evidence suggests that they originated during, or before, the early Jurassic Period.

From general biology section, discussing urea cycle: since prior to this the urea cycle was thought to have originated with the metazoans who appeared several hundreds of millions of years after the diatoms.

Stephpp (talk) 12:55, 24 June 2015 (UTC)

I think the bit on the urea cycle seriously garbles the primary source. I'm loathe to simply delete the text - since the work being referenced is of some ecological significant - but it'll require a bit of work to clean-up. I think that the evolutionary dates in the "offending" text are something of a red herring. Not least because metazoans appear in the fossil record a very long time before the diatoms (which isn't to say that there weren't cryptic ancestors of diatoms floating about). Cheers, --PLUMBAGO 14:14, 24 June 2015 (UTC)

Has these diatoms changed since the supposed Jurassic Period? Has there been any changes in the structure of these organisms after supposedly more than 65 million years? I say supposedly because they may not be that old. Earth may not be more than 10 thousand years old! 108.188.90.42 (talk) 18:23, 12 November 2015 (UTC)

It would be nice if the Earth weren't so old - it would certainly simplify the life of scientists studying it. Unfortunately, all of the evidence - including some from the diatoms - points the other way to an Earth with a (very) long and richly varied life. And individual scientists can spend their whole lives studying just one detailed facet of this long, long history. The alternative - a 10,000 year old Earth - would require everything we see to be a put-up job by an excellent faker, dead set on making everything look a million times older. Not a comfortable thought. Have a look over at Age of the Earth for a nice summary of where scientists think the evidence points these days. Thanks for visiting! --PLUMBAGO 08:32, 13 November 2015 (UTC)

No matter how uncomfortable, the truth is the truth. Evolutionists not only make too many assumptions, they also think that the evolution is a fact when it is still a theory. Many of the "evidences" for evolution can be seen as evidence for evolution or creation. Other "evidence" isn't really evidence at all. For example, Java man was put together using a human skull cap; some teeth; and a femur. Not enough evidence to say it wasn't a human but a transitional fossil. Another example: the Cambrian explosion as seen in the fossil record doesn't compute with evolution. Darwin said that nature does not jump; but we see in the fossil record that nature made a large jump, either that or God made everything together on the first 6 days of creation. I don't mean to debate, I just believe evolution has some flaws that need to be pointed out and evolution needs to be corrected or thrown out. — Preceding unsigned comment added by 108.188.90.42 (talk) 14:25, 19 November 2015 (UTC)

Very true - the truth will out in the end. The two examples you raise do have a bit of history behind them, but views of them have changed a lot since they were first raised as evidence of evolution. Getting a grip on the ancestors of humans has come on leaps and bounds as more fossils - and more complete fossils - are discovered. And understanding is further enhanced by genetic information that allows the evolutionary separation between living species to be estimated (and separately across multiple genes). The Cambrian explosion remains something of a hot topic in biology, and there's not complete consensus on what it represents. But from a number of lines of evidence, including new fossils and genetics, it looks like it may not be the "explosion" originally envisaged, and may even represent a revolution in fossil preservation (more hard parts) rather than a revolution in phylogeny. But these are specific research topics where we're still discovering things. That's not quite as true for evolutionary theory where, to first order, Darwinian mechanisms remain king. Given the theory's simplicity (variation + selection + time = directed evolutionary change), it's not difficult to understand why. Anyway, have a look at the articles on the topics you mention - things have been moving along! Cheers, --PLUMBAGO 11:26, 20 November 2015 (UTC)

Requested move 10 May 2016

The following is a closed discussion of a requested move. Please do not modify it. Subsequent comments should be made in a new section on the talk page. Editors desiring to contest the closing decision should consider a move review. No further edits should be made to this section.

The result of the move request was: not moved. (non-admin closure) kennethaw88 • talk 02:45, 18 May 2016 (UTC)

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Diatom → Bacillariophyceae. – Diatom is not the scientific name of the class and even confusing with Chemistry domain. At least it should be renamed to Diatomeae 91.117.65.254 (talk) 15:58, 10 May 2016 (UTC)

• Oppose — this is the common name by which this group is referred to both colloquially and in many scientific circles. It would be confusing to move to a name that is not - in my experience - much used outside of taxonomy. Without wishing to put too much weight on this, parallels can be drawn with articles on class names like Mammalia and Aves, which are actually redirects to the common names Mammal and Bird. I understand the impetus to move the article to the more accurate name (well, the currently most accurate name), but I do not think it would benefit most readers. --PLUMBAGO 12:36, 11 May 2016 (UTC)
• Oppose. There doesn't seem to be sufficient scientific consensus as to what rank based scientific name should be used for diatoms. Our higher taxonomy articles in this area are a mess. Algaebase has Coscinodiscophyceae as a class in phylum Bacillariophyta. The Coscinodiscophyceae taxobox has them as an order in Bacillariophyceae, but the article text introduces them as a class. Diatom has Heterokontophyta as a phylum, while that article treats heterokonts as a superphylum. If we go with Algaebase it should be Bacillariophyta, but that's not consistent with how the lower ranking diatom articles on Wikipedia present things. Plantdrew (talk) 16:49, 11 May 2016 (UTC)
• Oppose Diatom is the commonly used term to cover this topic. Whether it is scientifically accurate is not the point; we are not writing a science journal but an encyclopedia of general knowledge. Per WP:NAMINGCRITERIA, the common name of a thing should be used wherever possible. WikiDan61^ChatMe!_ReadMe!! 17:17, 11 May 2016 (UTC)
• Oppose per all the above, WP:COMMONNAME being the main issue. If the taxonomy gets sorted out better, we should have articles on the taxa, with Diatom being a WP:CONCEPTDAB. See various other biology articles dealing with the same issue of a vernacular generic term not aligning with the taxonomy (especially the modern cladistic breakdown).  — SMcCandlish ☺ ☏ ¢ ≽^ʌⱷ҅_ᴥⱷ^ʌ≼  08:45, 13 May 2016 (UTC)

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The above discussion is preserved as an archive of a requested move. Please do not modify it. Subsequent comments should be made in a new section on this talk page or in a move review. No further edits should be made to this section.

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External links modified (January 2018)

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I have just modified one external link on Diatom. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

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Lead revisions

WPMOS states the Lead is a four paragraph summary of an article, presented in the same order as in the article itself. I am revising this Lead to meet those guidelines. It is my style to make one edit at a time rather than draft an entire new Lead and replace the old one with a single edit, so bear with me and please do not revert or edit my edits until I have completed revising the entire Lead. Then have at it. This will take me a few hours. Regards, IiKkEe (talk) 14:40, 29 April 2018 (UTC)

Article reorganization

I have completed a reorganization of this Article with virtually no change in its content, but lots of new Section and Subsection titles and rearranging. Comments here are welcomed. Regards, IiKkEe (talk) 18:26, 29 April 2018 (UTC)

Nice going - it's been necessary for a good while. But can we not have - even temporarily - sections entitled "Random facts" please? It might be better in such cases to work on a copy of the article in your sandbox until this sort of thing doesn't appear in the main page. But thanks for the otherwise good work! Cheers, --PLUMBAGO 07:54, 3 May 2018 (UTC)

PLUMBAGO Thanks for input from the number one editor of this article (over 34,000 characters added) who has been following it since 2004. Advice heeded re "Random facts" section - that was a bad idea on my part, I will distribute/delete these dangling sentences ASAP. Regards, IiKkEe (talk) 15:16, 3 May 2018 (UTC)

Oceanic silicon cycle diagram

It is with some reluctance that I delete the silicon cycle diagram because it summarizes alot of info nicely, but I do so for the following reasons 1) there is no caption to explain the diagram, 2) there is no narrative in the article on that subject, 3) it more properly belongs in the article on silicon, not diatoms, and 4) there is no mention of diatoms in the diagram. If I am missing something, please let me know here, where we can discuss and possibly revert. Regards, IiKkEe (talk) 20:41, 4 May 2018 (UTC)

Hi IiKkEe. That's something I added a good while ago, largely based on the budget of Treguer et al. (1995). I take your point about the lack of an obvious connection to the diatoms. It may be worth reinstating but making clear that the vast majority of the biological production is diatom-based. The reason it didn't say this is because other organisms (radiolarians, silicoflagellates, glass sponges) do also play a small role in the cycle. Although it's fleetingly mentioned in the section on their evolutionary history, the point could be more clearly made that they dominate the modern silicon cycle in the ocean. Hence why mentioning the cycle here - they really have altered it far beyond that of their evolutionary precursors (per the evolutionary history section). Cheers, --PLUMBAGO 13:10, 8 May 2018 (UTC)

PLUMBAGO Thank you for your perspective and suggestion that the diagram be reinstated. I agree and will do so momentarily; and will add a subsection titled "Contribution to the silicon cycle" where a narrative can be generated to complement the diagram. Please contribute to that narrative, and expand the caption on the diagram to more fully explain its format, as time allows and you see fit.

Its great when editors collaborate rather than combat! Regards, IiKkEe (talk) 12:46, 9 May 2018 (UTC)

Done. Hope this is clearer. PLUMBAGO 13:38, 10 May 2018 (UTC)

I like it, I like it. Could you add to the caption what units are used (eg "Magnitude is expressed in units of ....")? I can't even guess what they might be... IiKkEe (talk) 15:14, 10 May 2018 (UTC)

That's a fair cop. The units are teramoles of Si per year. I'll get that added, and will try to unpack it a little - I don't imagine "moles" are particularly helpful. Cheers, --PLUMBAGO 15:57, 10 May 2018 (UTC)

PLUMBAGO Again, I like it. The next area I hope you can help with is to expand a bit the narrative of the article associated with the diagram: at this point, the caption has more info than the article(!) For example, would the sentence about silicic acid be better placed in the article, since it is not mentioned in the diagram? I hope you can help... IiKkEe (talk) 17:09, 10 May 2018 (UTC)

FYI: summary of recent edits

In the last 22 days I have made over 225 edits to this page. Most have been directed toward the Lead; and the Section and subsection titles as reflected in the Table of contents. Here is a comparison of the previous and current Leads, and previous and current TOCs:

Previous lead as of April 23, 2018

Diatoms are a major group of microalgae, and are among the most common types of phytoplankton. Diatoms are unicellular, although they can form colonies in the shape of filaments or ribbons (e.g. Fragilaria), fans (e.g. Meridion), zigzags (e.g. Tabellaria), or stars (e.g. Asterionella). The first diatom formally described in scientific literature, the colonial Bacillaria paradoxa, was found in 1783 by Danish naturalist Otto Friedrich Müller. Diatoms are producers within the food chain. A unique feature of diatom cells is that they are enclosed within a cell wall made of silica (hydrated silicon dioxide) called a frustule. These frustules show a wide diversity in form, but are usually almost bilaterally symmetrical, hence the group name. The symmetry is not perfect since one of the valves is slightly larger than the other, allowing one valve to fit inside the edge of the other. These shells are used by humans as diatomaceous earth, also known as diatomite. Fossil evidence suggests that they originated during, or before, the early Jurassic period. Only male gametes of centric diatoms are capable of movement by means of flagella. Diatom communities are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality.

Current lead as of May 15, 2018

Diatoms (diá-tom-os "cut in half", from diá, "through" or "apart"; and the root of tém-n-ō, "I cut".) are a major group of microorganisms found in the oceans, waterways and soils of the world. Living diatoms number in the trillions: they generate about 20 percent of the oxygen produced on the planet each year;; take in over 6.7 billion metric tons of silicon each year from the oceans in which they live; and contribute nearly half of the organic material found in those oceans. Masses of living oceanic diatoms can be seen with the naked eye from the International Space Station. The shells of dead diatoms can reach as much as a half mile deep on the ocean floor; and the entire Amazon basin is fertilized by diatom dust transported by westerly transAtlantic winds from the bed of a large dried up lake once covering much of the African Sahara.

Diatoms are unicellular; they can live alone or form colonies, taking shapes such as ribbons, fans, zigzags, and stars. They range in size from 2 to 200 micrometers. Diatoms have two shapes: a few (centric diatoms) are radially symmetric, while most (pennate diatoms) approach being bilaterally symmetric: this shape is the reason for the group name diatoms. A unique feature of diatom anatomy is that they are surrounded by a cell wall made of silica (hydrated silicon dioxide), called a frustule. These frustules have structural coloration due to their photonic nanostructure, prompting them to be described as "jewels of the sea" and "living opals." Movement primarily occurs passively as a result of water currents; however, male gametes of centric diatoms have flagella, making them capable of active movement. Diatoms convert light energy to chemical energy by photosynthesis, an attribute they share with plants, although diatoms and plants evolved independently. Diatoms possess a urea cycle, a feature they share with animals, although it is used differently than in animals.

The study of diatoms is a branch of phycology. Diatoms are classified in the Domain Eukaryotes, organisms with membranes surrounding the cell nucleus, a property which aligns them with animals, and separates them from the prokaryotes Archaea and Bacteria. Diatoms are a type of plankton called phytoplankton, the most common of the four plankton types. Another classification divides plankton into eight types based on size: in this scheme, diatoms are a type of microalgae. Several systems for classifying the individual diatom species exist. Fossil evidence suggests that diatoms originated during or before the early Jurassic period.

Diatoms are a popular tool for monitoring environmental conditions, past and present, and are commonly used in studies of water quality. Collections of diatom shells found in the earth's crust are soft, silica-containing sedimentary rocks called diatomaceous earth (diatomite). This rock is easily crumbled into a fine powder and has a particle size typically 10 to 200 μm. It is used for a multitude of purposes including for water filtration, as a mild abrasive, in cat litter, and as a dynamite stabilizer.

11 Images

Regards, IiKkEe (talk) 19:56, 6 May 2018 (UTC) IiKkEe (talk) 17:17, 10 May 2018 (UTC), IiKkEe (talk) 20:15, 15 May 2018 (UTC)

References

External links

I have reviewed the WP guidelines for external links (EL's), and begun a review of the EL's on this page. I have deleted the first 3 I have reviewed and the reason in "View history". I will review the rest shortly; if there are objections to any deletions, let's talk here. Regards, IiKkEe (talk) 16:36, 16 May 2018 (UTC)

Pronounciation

is it "Dye-atom" /Dɑːiːæ'təm/ or "Dee-atom" /Diːæ'təm/ or "dy-a-TOM"? OsamaBinLogin (talk) 19:26, 1 June 2018 (UTC)

OsamaBinLogin. I believe a fourth possibility is the correct one: "DY-a-tom". Regards, IiKkEe (talk) 18:04, 3 June 2018 (UTC)

suggestions for revision

It is incorrect to say that diatoms are only phytoplankton. Diatoms also grow attached to substrates, thus should also be considered periphyton. (Vadeboncoeur and Power, 2017; also see Chapter 16 Raphid Diatoms in Freshwater Algae of North America: Ecology and Classification edited by Wehr et al., 2nd edition, 2015) Jsdawson90 (talk) —Preceding undated comment added 15:22, 12 July 2018 (UTC)

Jsdawson90 I don't see where it is said they are only phytoplankton; that is one accurate descriptive term. If you think periphyton is also appropriate, feel free to add it with your reference: WP procedure calls for edits to an article if needed, not suggesting edits on the Talk page. (The "B" in "BRD" stands for "Boldly edit"!)

Regards. IiKkEe (talk) 02:50, 13 July 2018 (UTC)

IiKkEe you are wrong. It is polite to suggest edits before adding them, and by stating that they are phytoplankton without reference to their functional role as periphyton then the implication is that they are only phytoplankton. Furthermore, I did make the edit, but someone removed it. Jsdawson90 (talk) —Preceding undated comment added 18:12, 27 July 2018 (UTC)

Jsdawson90 Thank you for your response and clarification. We do disagree re suggesting edits vs just making them, but IMO we can leave it at that and move on. I appreciate knowing you did make the edit, so I'm definitely out of line in that regard. I will look into who removed it and when and why when I get a moment.

Regards, IiKkEe (talk) 12:58, 31 July 2018 (UTC)

IiKkEe Ok, fair enough. I did need to make a note about why the edit was made, and that was reason enough to remove the edit the first time. It wasn't a MAJOR edit, so you're probably right in that it was not necessary to suggest the edit. Happy to leave it at that. Respectfully, Jsdawson90 (talk) 21:05, 17 August 2018 (UTC)

Please hyperlink "oxygen" in this article to the WIKI page on oxygen

I can't quite figure out how to do this? Diatoms should also be mentioned to the page about oxygen, something I'm having trouble with also. PharmDelicious (talk) 05:20, 6 January 2020 (UTC)

Orphan sentence in lead (July 2020)

Hi all, in its present version, the lead contains a sentence that does not correspond to anything in the article, which is not good Wikipedia practice - either an anomaly, or a leftover from a previous version - needs deleting from lead, or relevant context added to text... the sentence is this one:

"The family Rhopalodiaceae also possess a cyanobacterial endosymbiont called a spheroid body. This endosymbiont has lost its photosynthetic properties, but has kept its ability to perform nitrogen fixation, allowing the diatom to fix atmospheric nitrogen.[20]" (Also if kept, note that family names are normally not italicized - see e.g. Rosaceae - although genera and species are).

Regards - Tony Rees Tony 1212 (talk) 19:42, 17 July 2020 (UTC)

Urea cycle and relation to metazoa

In the section on the urea cycle, there is a statement I find confusing: "... diatoms have a functioning urea cycle was highly significant, since prior to this, the urea cycle was thought to have originated with the metazoans which appeared several hundreds of millions of years after the diatoms."

My problem is that I believe that diatoms have only existed for about 200 million years. So, if the statement is correct, then metazoa must be recent! I think metazoa existed long before diatoms appeared. Perhaps it is simply a minor error, with "after" appearing instead of "before". Can someone either explain my confusion or fix the statement? --AJim (talk) 03:07, 27 October 2020 (UTC)

I just saw that this issue was raised about 5 years ago here #Origin of diatoms. I think it really ought to be corrected. If no one objects, maybe I will change "after" to "before".--AJim (talk) 03:35, 27 October 2020 (UTC)

Typos in reference 98?

The text of reference 98 needs to checked. Wprlh (talk) 17:19, 3 May 2021 (UTC)

Wiki Education Foundation-supported course assignment

This article was the subject of a Wiki Education Foundation-supported course assignment, between 7 January 2019 and 9 April 2019. Further details are available on the course page. Student editor(s): Schneidl12.

Above undated message substituted from Template:Dashboard.wikiedu.org assignment by PrimeBOT (talk) 19:27, 16 January 2022 (UTC)