Talk:Endosymbiotic theory

message: As per a discussion with mav on the Endosymbiont page, I've created this page on the Endosymbiotic Hypothesis, by editing the content of a previous version of the Endosymbiont page (circa late Dec 2002).
Currently, I think the evidence I offer in support of the Endosymbiotic Hypothesis is fairly weak, and much of the evidence seems consistent with a variety of other hypotheses.  For example, here's an obvious alternate hypothesis (I'm not saying this is a good one, just that it's an alternative):
* the ancestor of eukaryotes started to sequester ATP synthesis into certain regions of the cell, e.g. to make the reactions more efficient (I'm no biochemist at all, but I understand there are advantages)
* eventually a membrane evolved around this ATP synthespropose variations on the (not especially good) hypothesis I just stated, or other alternate hypotheses.
Ideally, this article should cite the evidence that more-convincingly indicates that the Endosymbiotic Hypothesis is probably correct, and other hypotheses (like the one I just made up) are significantly less plausible.  Currently the only evidence I offer that gets at this is that phylogenetic evidence indicates that chloroplasts are more closely related to cyanobacteria than anything else.  (Well, perhaps we could argue that ancient eukaryotes got DNA from cyanobacteria through horizontal transfer of DNA.)  It's certainly my perception that this theory is generally accepted, but I feel I don't have all the arguments.
Another thing that would be nice is a historical discussion of what prompted Dr. Margulis to form the Endosymbiotic Hypothesis.
Finally, I think there might be some overlap with the very extensive (but IMHO not entirely desirably) article on evolution of flagella, but maybe that's something for another day.
Anyway, I don't know much about this theory, so I'm unlikely to be able to do this, but I hope what I've said is motivating to someone who knows more.
--User:zashaw
Thanks for laying all this out. The article as is also looks good - of course much more can and should eventually be written. If I find time I'll brush-up a bit on my cellular evolution and give it a go. --mav 04:05 Feb 23, 2003 (UTC)
----
I added this: Protista with chloroplasts are often more closely related to forms lacking than to each other, suggesting chloroplasts appeared more than once.  This could be expanded on - I think the presence of nucleomorphs in the chloroplasts of cryptomonads and chlorarachniophytes has been considered a spectacular piece of evidence for the endosymbiotic hypothesis, though it shows chloroplasts secondarily derived from eukaryotic rather than prokaryotic ancestors.  However, chances are a full discussion of the various sorts of chloroplasts (like the probably confusing blurb I wrote on that page) would simply be distracting.  Does anyone have ideas on how this could be worked in?
I've taken the "extensions" part out that's sat without citations for 3 & 1/2 years. It basically did a poor job of trying to punch holes in the theory without any evidence. If someone wants it back in, they can bring citations next time. 129.137.215.236 (talk) 06:01, 10 December 2012 (UTC)
thread_title: Evidence?

message: This article states that: "The endosymbiont theory of mitochondria and chloroplasts was proposed by Lynn Margulis."  This is not true.  The endosymbiont theory of mitochondria and chloroplasts was proposed by scientists in the 19th century (including Russian scientists). Wallin wrote a book in 1927 called Symbionticism and the Origin of Species. yo.  Dr. Margulis's role has been to popularize the endosymbiont theory of mitochondria and chloroplasts.
Bob Bloodgood
Department of Cell Biology
University of Virginia school of Medicine
hello
I just checked. I wrote that. I doubt I invented it, so if what you say is right, I obviously used a source which was putting untrue claims. Please do edit the article accordingly. I will check on my side what I can find on the topic. Anthère
Indeed. I found the name of one of the author C. Mereschkovsky. Would you by any chance know more precisely the nature of this biologist initial claim, so we could see on in which direction Margulis work has been extensive ?
I found a reference, and have changed the page accordingly.  It really looks like this page relies heavily on Margulis-based popularizations, and I think it might miss many important ideas.  I'm not sure if discussing her ideas about the cooperative biosphere is entirely relevant. Josh
Hi everyone,  I'm probably breaking wikipedia protocol or something I've never submitted anything to wikipedia but I'm doing some writing about mitochondria right now and I saw something that might need some minor editing in the "history section".  According to the book "mitochondria" by Immo Scheffler, R, Altman propsed that mitochondria were "autonomous, elemental living units, forming bacteria-like colonies in the cytoplasm of the host cell." in a book he wrote in 1890.  Granted Altman referred to mitochondria as Elementarorganismen but it does seem to me that Altman described the endosymbiotic theory.
Perhaps Altman should be mentioned in the article as his work precedes Konstantin Mereschkowsky?  I won't make the edit since I have no idea how wikipedia functions for editting.
The reference for Altman's work is:
Altman, R., Die Elementar Organismen und ihre Beziehung zu den Zellen (Veit, Leipzig, 1890).
Cheers, Guah  —Preceding undated comment added 01:54, 3 April 2009 (UTC)
thread_title:  Credit for Endosymbiotic Hypothesis 

message: I removed the external link
*The Birth of Complex Cells - by Christian de Duve
because it was broken.  If this article/page is indispensible, and you know of its new url, please fix it. 
Safay 07:49, 8 May 2005 (UTC)
thread_title:  another minor correction 

message: This word is new to me.  I clicked on the Wikipedia link provided but it is only an historical explaination of the Helots.  Wiktionary does not have an entry for this word.  Mirriam-Webster gives the same historical definition and gives it as a synonym for slavery.  Is there any reason not to use the word slavery here, if that's what is meant?
Incidentally, I would argue that this kind of endosymbiosis leading to organelle is not slavery.  The host is a habitat.  Often endosymbionts are maintained at population levels far above what they could acheive without a host.  Once you start to get genomic integration, the individual identities of the two, host and symbiont, get eroded and the holobiont starts to become a new kind of fused individual.  I was initially excited about the word "helotry" because I thought maybe it elegantly captured this process, but upon looking it up was dissapointed to discover it only meant slavery.
Safay 08:04, 7 November 2005 (UTC)
thread_title:  Helotry 

message: Does anyone feel that pages like Cellular evolution or Evolution of cells should redirect to this page or any others. RENTASTRAWBERRY FOR LET? röck 01:13, 29 November 2005 (UTC)
replies: text: Endosymbiotic theory should be a topic within Evolution of cells, if you ask me.   Safay 09:05, 1 December 2005 (UTC)
thread_title: Redirect

message: Corrected some info re: who came up with what.  Fixed the flagella not being thought to result from endosymbiosis (which is false). A lot of the info is only half true or big generalisations, which I might fix later if I can do it without being long winded.  One of the big assumptions in this article was that whatever was engulfed and became part of the host needed to have DNA.  This isn't really true since something bigger (a multicellular protist that needs to eat other simpler organisms to survive) can engulf a simple photosynthetic algae and take apart that algae and basically reassign the use of the major algae components for whatever it wants.  I.e. take off the flagella and use it for locomotion, and keep the photosynethic algae bit in another part, etc.  Once it divides only one daughter cell gets to keep the original algae, but the flagella might go to another daughter cell, so then you'd have a protist without any algae inside but with a flagella.--Scyfer 15:02, 8 February 2006 (UTC)
replies: text: Josh, I agree.  While the flagellum may have evolved from a spriochete (which there is not much evidence for, or support for as a theory in the scientific community, as far as I am aware) I don't think that there is any evidence or even anyone out there suggesting that endosymbiosis has resulted in a kind of adoption of modular parts of cells, as suggested by Scyfer.  The cell would still need the genetic information somewhere for it to be a structure passed along in the lineage.  When we do have structures like hydrogenosomes that are presumed to come from endosymbiosis events but do not contain DNA, it is thought that indeed the endosymbiont did have DNA, but that DNA was transferred to the nucleus over evolutionary time. Safay 00:28, 4 March 2006 (UTC)
replies: text: Are here other criteria? If so, suggest editing to show less confdence in DNA as the criterion.  DGG 03:28, 19 September 2006 (UTC)
thread_title:  Corrections 

message: Should this theory (which states that the cell nucleus evolved from a large DNA virus) be included here? It seems to be gaining support as ever larger, more complex DNA viruses (such as Mimivirus) are discovered. archola 01:26, 9 February 2006 (UTC)
thread_title:  Viral Eukaryogenesis? 

message: Pretty superfluous section at the moment but I don't have the heart to just delete it, given that I haven't worked on this article before. 
Points 2,3 and 4 of the current problems sections don't belong here. They are aspects of eukaryote evolution that are being discussed in current research, but not 'problems of the endosymbiont theory'. While they are valid points, they should be in an article about the evolution of eukaryotes and nowhere else. Point 1 isn't actually a problem. The way endosymbiotic relationships go it would require a miracle equal to a divine intervention to get organelles that are able to survive outside the host cell. Not even relatively "new" endosymbionts that have been living inside their host for only 40 million years or so manage to do that anymore. 
The Problems section is very poorly written, and lacks any citations.  The first bullet states: "Some form of transfer between nuclear and mitochondrial/plastid DNA must have taken place..." [emphasis mine], then goes on to say "...or, alternatively, a mechanism for turning off portions of early proto-mitochondrial/plastid DNA must have been in place in early symbiotes." [emphasis mine] If the first one must have happened, then how could the second be an alternative, which also must have happened?  For the second point, I'm not sure any reasonable person can say the problem is "easily accounted for" by stating DNA transfer had to have taken place.  I'm not up on all the research in this area, but I don't recall ever seeing anyone give a decent explanation as to how this transfer occurs (retrotransposition has problems, in my opinion).  If there is, then it should be cited -- even retrotranspositions, if that's what we have.
More importantly, there are no citations.  This is crucial when trying to answer problems with the theory.  Right now, this section says, "the reason these problems aren't serious is because it must have happened as indicated." Ted 17:10, 23 April 2006 (UTC)
replies: text: Removed an incoherent paragraph on chloroplast-mitochondrial cross influences (or at least that's what I think it was about. And the even more absurd one by the same web address,  70.187.235.73, both of which you can see in the history. If it was a joke, it was a rather good one. DGG 00:02, 20 September 2006 (UTC)
thread_title:  Problems Section 

message: The diagram badly needs a caption. Is this a genuine hypothesis of the evolution of some organism? If so, which? (Or is it just illustrative of the possibilities?) Which organisms are indicated by the letters A to I? What do the numbers 1 to 4 mean? Gdr 11:07, 29 May 2006 (UTC)
replies: text: I agree. Maybe the article should have a diagram that includes alternative hypotheses such as the idea that both prokaryotes and Archaea may have been involved in the origin of eukaryotic cells. The  Endosymbiotic theory article could expand on the Hydrogen hypothesis. There could also be mention of other ideas such as the proposal that viral introductions of genes have been important in the origin of eukaryotic cells. --JWSchmidt 14:43, 23 June 2006 (UTC)
thread_title:  Diagram needs a caption 

message: Should a link to Polydnavirus be added to the See Also section?  It's not precisely an example of endosymbiotic theory, but it is related.
Kabu 20:31, 2 June 2006 (UTC)
thread_title:  Polydnavirus? 

message: Why is most of the article usingthe term "plastid" , when also saying it is equivalent  to chloroplast?
Has "plastid" ever been used in a broader sense? Has any other organelle but the chloroplast ever been called a "plastid"
If not, chloroplast is the more familiar word. DGG 03:28, 19 September 2006 (UTC)
thread_title: plastid or chloroplast

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thread_title:  Peer Review javascript 

message: If the pre-mitochondria were Rickettsiales-like, intra-cellular parasites... then, perhaps the first true Eukaryote was formed, through phagocytosis (e.g. Amoeba), when it envoloped & digested infected cells ? 66.235.26.150 (talk) 12:39, 6 October 2010 (UTC)
thread_title:  Originally a result of phagocytosis? 

message: I don't understand why this theory is often referred to as Endosymbiotic Theory, rather than its correct title, Endosymbiosis Theory. Margulis never calls it Endosymbiotic Theory as far as I know, but (Serial) Endosymbiosis Theory. Similarly Dawkins, when he refers to it (quoted in the article). It's incorrect English, isn't it? In other areas of biology, we don't refer to Cellular Theory, but Cell Theory; and it's Chromosome Theory, not Chromosomal Theory. The same is true in other sciences: e.g. in physics, it's String Theory, not Stringy Theory...  —Preceding unsigned comment added by 83.104.37.40 (talk) 14:12, 19 October 2009 (UTC)
thread_title:  Endosymbiosis not endosymbiotic? 

message: This article has a fantastic list of refs. While it is true that the lists of evidence and problems with the theory might include some inline citations, this article seems better than start to me, and perhaps the banners should be removed or altered to be more specific about what needs to be done. Michaplot (talk) 17:59, 13 October 2010 (UTC)
thread_title:  Time to Upgrade? 

message: ...Is this vandalism, or just strange-looking and unexplained?  —Preceding unsigned comment added by 128.135.194.100 (talk) 08:12, 15 October 2010 (UTC)
thread_title: Who...is Banjo Jim?

message: Thanks for the recent changes Dadrepus. I have reverted the edit relating to the claims about organ-specific compartments for two reasons: no reference given; and the claim as written is obscure. What are lytic and organ specific compartments, etc. Please fix these issues and re add your contribution. 
Also, you might want to create a user page for yourself so we can talk to you directly.
Thanks!Michaplot (talk) 20:30, 1 November 2010 (UTC)
thread_title:  Recent Changes 

message: Merge discussion can be found here https://en.wikipedia.org/wiki/Talk:Symbiogenesis --prokaryotes (talk) 09:36, 4 September 2014 (UTC)
replies: text: I agree, please merge (and redirect from Symbiogenesis to Endosymbiosis. Peteruetz (talk) 17:34, 1 October 2014 (UTC)
replies: text: *Unanimous decision is to merge. As prokaryotes suggest symbiogenesis is the proper scientific name as introduced my Mereschowsky and adopted even to this day by Lynn Margulis, the two leading proponents. In fact the origin of the phrase 'endosymbiotic theory' is not clear. Chhandama (talk) 02:24, 6 October 2014 (UTC)
thread_title:  Merge 

message: Substituted at 05:10, 13 May 2016 (UTC)
thread_title: Assessment comment