# Symbiosis does not develop over time **URL:** \ **Category:** Great Debates\ **Created:** [June 3, 2013, 6:29pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054 "2013-06-03T18:29:49Z")\ **Posts on this page:** 20\ **Page:** 2
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 9:26pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/21 "2013-06-03T21:26:47Z")
> [@Der\_Trihs](#): > > On the contrary, that’s what a True Scotsman keeps in his sporran; his symbiote! > > It seems a common theme of creationists to pretend that the gradual change of evolution isn’t even conceivable; “what use is half an eye”. Or in this case, “what use is half a symbiote?” Its not about what is ‘conceivable’. Its what you can prove. This is why I have been asking for citations. Thanks for your input though. ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 9:28pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/22 "2013-06-03T21:28:41Z")
> [@Colibri](#): > > First, define exactly what you mean by symbiosis. > > One of the classic examples of a symbiotic relationships is lichens, involving species of fungi and algae. In many cases both the fungus and the algal species are able to live separately. The symbiosis can develop over the lifetime of the organisms, not over evolutionary time. > > Another is between coral and the algal zooanthellae that usually live in their tissues. Again, both partners are capable of living separately. The symbiosis develops during the lifetime of the organisms. I am referring to obligate symbiotic relationships. It can be debated that non-obligate symbiotic relationships are simply mutualistic relationships, which i referred to in my opening post. ---
**Author:** ![Czarcasm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/czarcasm/32/4050_2.png) [@Czarcasm](https://boards.straightdope.com/u/Czarcasm)\ **Post date:** [June 3, 2013, 9:33pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/23 "2013-06-03T21:33:26Z")
> [@reef\_shark](#): > > I am referring to obligate symbiotic relationships. It can be debated that non-obligate symbiotic relationships are simply mutualistic relationships, which i referred to in my opening post. Will you accept fossil records as evidence? ---
**Author:** ![jayjay](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jayjay/32/6765_2.png) [@jayjay](https://boards.straightdope.com/u/jayjay)\ **Post date:** [June 3, 2013, 9:55pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/24 "2013-06-03T21:55:50Z")
Okay, here’s sticking to the topic. Creationism is fantasy and no amount of handwaving obfuscation will make it real. I don’t really care to try to convince you of that since you can’t reason someone out of a position they didn’t reason themselves into, and frankly, you can carry this fantasy to the grave with you without it really affecting my life one bit. Have fun flailing while other, less-burnt-out Dopers attempt to school YOU about this subject. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 3, 2013, 9:57pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/25 "2013-06-03T21:57:22Z")
> [@reef\_shark](#): > > I am referring to obligate symbiotic relationships. It can be debated that non-obligate symbiotic relationships are simply mutualistic relationships, which i referred to in my opening post. I don’t know what you mean by “simply mutualistic.” As I have already pointed out, there is no sharp dividing line between obligate mutualism and non-obligate relationships. It is a continuum. All stages of interdependence can be found in closely related organisms. The distinction you are trying to make doesn’t exist. For example, in [lichens:](https://en.wikipedia.org/wiki/Lichen) > [@](#): > > Lichen associations may be examples of mutualism, commensalism or even parasitism, depending on the species. > [@](#): > > A particular fungus species and algal species are not necessarily always associated together in a lichen. One fungus, for example, can form lichens with a variety of different algae. The thalli produced by a given fungal symbiont with its differing partners will be similar, and the secondary metabolites identical, indicating that the fungus has the dominant role in determining the morphology of the lichen. Further, the same algal species can occur in association with different fungal partners. Lichens are known in which there is one fungus associated with two or even three algal species. Rarely, the reverse can occur, and two or more fungal species can interact to form the same lichen.[18] Regarding the coral symbiont [Symbiodinium](http://en.wikipedia.org/wiki/Zooxanthella): > [@](#): > > The large diversity of Symbiodinium revealed by genetic analyses is distributed non-randomly and appears to comprise several guilds with distinct ecological habits (Fig. 8). Of the many Symbiodinium characterized genetically, most are host-specific, mutualistic, and dominate their host.[43] Others may represent compatible symbionts that remain as low-abundance background populations because of competitive inferiority under the prevailing external environmental conditions (e.g. high light vs. low light).[44] Some may also comprise opportunistic species that may proliferate during periods of physiological stress and displace the normal resident symbiont and remain abundant in the host’s tissues for months to years before being replaced by the original symbiont.[45][46][47] There are also those that rapidly infect and establish populations in host juveniles until being replaced by symbionts that normally associate with host adult colonies.[48] Finally, there appears to be another group of Symbiodinium that are incapable of establishing endosymbiosis yet exist in environments around the animal or associate closely with other substrates (i.e. macro-algal surfaces, sediment surface) Do you accept that non-obligate mutualistic relationships evolved over time? ---
**Author:** ![Mangetout](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mangetout/32/19_2.png) [@Mangetout](https://boards.straightdope.com/u/Mangetout)\ **Post date:** [June 3, 2013, 10:07pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/26 "2013-06-03T22:07:34Z")
Do you accept _any kind of change over time_? If not, we need to start there. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 3, 2013, 10:28pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/27 "2013-06-03T22:28:25Z")
> [@Der\_Trihs](#): > > On the contrary, that’s what a True Scotsman keeps in his sporran; his symbiote! > > It seems a common theme of creationists to pretend that the gradual change of evolution isn’t even conceivable; “what use is half an eye”. Or in this case, “what use is half a symbiote?” [Oh, that again](http://rationalwiki.org/wiki/Irreducible_complexity#Examples_of_flawed_arguments) . . . > [@](#): > > **Examples of flawed arguments** > > Frequently, believers in this philosophy cite the eye as an example of something too complex to have evolved. The argument is frequently presented with a question of the type, “What use is half an eye?”. However if the question is recast as “Given a choice, would you prefer to be completely blind or have 50% of your present vision?”, then it becomes clear that the question is badly formed, especially when keeping in mind that many species manage to survive with significantly less advanced eyes. Examples include the polychaete worms, which can distinguish between light and dark;[5] the simple eye-cup of the flatworms, for finding the direction of a light source; jellyfish and scallops, with simple eyes for detecting movement;[6] the famous compound eyes of the insects, which can make out simple shapes, and ultimately the sophisticated single-lens eyes of the molluscs and vertebrates. > > \ > > Although irreducible complexity is offered as evidence of intelligent design, this conclusion is questionable. Robustness is generally considered to indicate good design, not precariousness. Which parachute would you consider better designed - one which ceased to function if a single part was missing, or one which has a back-up pullcord? Irreducible complexity is at best evidence for crappy design. ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 10:45pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/28 "2013-06-03T22:45:53Z")
> [@jayjay](#): > > Okay, here’s sticking to the topic. Creationism is fantasy and no amount of handwaving obfuscation will make it real. I don’t really care to try to convince you of that since you can’t reason someone out of a position they didn’t reason themselves into, and frankly, you can carry this fantasy to the grave with you without it really affecting my life one bit. Have fun flailing while other, less-burnt-out Dopers attempt to school YOU about this subject. Please try again, the thread is about Symbiosis. ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 10:47pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/29 "2013-06-03T22:47:59Z")
> [@Colibri](#): > > I don’t know what you mean by “simply mutualistic.” As I have already pointed out, there is no sharp dividing line between obligate mutualism and non-obligate relationships. It is a continuum. All stages of interdependence can be found in closely related organisms. The distinction you are trying to make doesn’t exist. > > For example, in [lichens:](https://en.wikipedia.org/wiki/Lichen) > > Regarding the coral symbiont [Symbiodinium](http://en.wikipedia.org/wiki/Zooxanthella): > > Do you accept that non-obligate mutualistic relationships evolved over time? The dividing line is that in obligate relationships, those organisms require each other for survival. Mutualistic relationships show a benefit for both parties, but the relationship is not required for survival. Requirement for survival is the dividing line. ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 10:49pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/30 "2013-06-03T22:49:09Z")
> [@Mangetout](#): > > Do you accept _any kind of change over time_? If not, we need to start there. If it is a change from mutualistic to obligate, then yes, that is what I meant to ask for originally. ---
**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\ **Post date:** [June 3, 2013, 10:52pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/31 "2013-06-03T22:52:27Z")
> [@reef\_shark](#): > > The dividing line is that in obligate relationships, those organisms require each other for survival. Mutualistic relationships show a benefit for both parties, but the relationship is not required for survival. Requirement for survival is the dividing line. There is no clear dividing line, as I have already indicated. You are making an artificial distinction. > [@reef\_shark](#): > > If it is a change from mutualistic to obligate, then yes, that is what I meant to ask for originally. A change in the relationship from non-obligate to obligate can occur in the lifespan of a single organism. Your distinction makes no biological or evolutionary sense. Please answer the question: Do you accept that non-obligate mutualistic relationships evolved over time? If you don’t, then there’s no point in talking about obligate ones. ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 10:53pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/32 "2013-06-03T22:53:52Z")
> [@Czarcasm](#): > > Will you accept fossil records as evidence? I will consider any citations or evidence that are provided here, and it will be appreciated. Here’s an OT question, would you accept fossil records as evidence of a flood? ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 11:00pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/33 "2013-06-03T23:00:12Z")
> [@Colibri](#): > > There is no clear dividing line, as I have already indicated. You are making an artificial distinction. > > A change in the relationship from non-obligate to obligate can occur in the lifespan of a single organism. Your distinction makes no biological or evolutionary sense. > > Please answer the question: Do you accept that non-obligate mutualistic relationships evolved over time? If you don’t, then there’s no point in talking about obligate ones. > **[Symbiosis](https://en.wikipedia.org/wiki/Symbiosis)** > > Symbiosis (Ancient Greek συμβίωσις symbíōsis: living with, companionship \< σύν sýn: together; and βίωσις bíōsis: living) is any type of a close and long-term biological interaction, between two organisms of different species. The two organisms, termed symbionts, can be either in a mutualistic, a commensalistic, or a parasitic relationship. In 1879, Heinrich Anton de Bary defined symbiosis as "the living together of unlike organisms". > The term is sometimes more exclusively used in a restricted, ... 'The definition of symbiosis is controversial among scientists. Some believe symbiosis should only refer to persistent mutualisms, while others believe it should apply to any types of persistent biological interactions (i.e. mutualistic, commensalistic, or parasitic).[5] Some symbiotic relationships are obligate, meaning that both symbionts entirely depend on each other for survival. ’ I did not make this up. Can you please cite an example of how ‘A change in the relationship from non-obligate to obligate can occur in the lifespan of a single organism.’?? Thank you. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 3, 2013, 11:03pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/34 "2013-06-03T23:03:48Z")
> [@reef\_shark](#): > > I will consider any citations or evidence that are provided here, and it will be appreciated. Begin with those provided **so far** in this thread, if you will. > [@reef\_shark](#): > > Here’s an OT question, would you accept fossil records as evidence of a flood? Certainly fossil records are accepted as evidence of [extinction-level events](http://en.wikipedia.org/wiki/Extinction-level_event#Major_extinction_events). Five major ones and 17 lesser ones have been identified so far. None was caused by a global flood, however, and none was more recent than 50,000 years ago. See the RationalWiki page on [Flood geology](http://rationalwiki.org/wiki/Flood_geology). ---
**Author:** ![reef\_shark](https://avatars.discourse-cdn.com/v4/letter/r/bbe5ce/32.png) [@reef\_shark](https://boards.straightdope.com/u/reef_shark)\ **Post date:** [June 3, 2013, 11:49pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/35 "2013-06-03T23:49:45Z")
> [@BrainGlutton](#): > > Begin with those provided **so far** in this thread, if you will. > > Certainly fossil records are accepted as evidence of [extinction-level events](http://en.wikipedia.org/wiki/Extinction-level_event#Major_extinction_events). Five major ones and 17 lesser ones have been identified so far. None was caused by a global flood, however, and none was more recent than 50,000 years ago. See the RationalWiki page on [Flood geology](http://rationalwiki.org/wiki/Flood_geology). I already asked the poster who linked the wiki page to explain how that applies to symbiosis developing over time, rather than just being a list of relationships. Just to be clear, symbiosis is not the same as mutualism. How do you know none were more recent than 50,000 years ago? Radiometric dating (especially the methods your cite mentions) are based on several inherent assumptions. Your cite lists uranium, potassium and thorium, but not carbon-14 dating, not surprisingly. Also, not all the water came from rain, as that same section claims, but also from the fountains of the deep. So the released heat is not an issue. bbl ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [June 3, 2013, 11:53pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/36 "2013-06-03T23:53:14Z")
> [@reef\_shark](#): > > Here’s an OT question, would you accept fossil records as evidence of a flood? Certainly fossils and other geologic indicators are used as evidence of prehistoric floods. There’s an entire subfield of geology called “paleoflood hydrology” that studies this subject, and fossilized remains of flood debris are definitely part of the evidence they analyze. (See an overview of paleoflood hydrology and its history [here (pdf)](http://home.shirazu.ac.ir/~kompani/DryLandHydrology/papers8788/baker-paleofloodHydrology-Geomorph-2008.pdf).) If what you’re asking is whether existing fossil records provide any credible scientific evidence for a universal worldwide paleoflood interpreted as the Biblical Noachian deluge, though, the answer is no, they do not. As **BrainGlutton** notes, paleofloods are not implicated in any prehistoric mass extinction events. ---
**Author:** ![Kimstu](https://avatars.discourse-cdn.com/v4/letter/k/ecd19e/32.png) [@Kimstu](https://boards.straightdope.com/u/Kimstu)\ **Post date:** [June 3, 2013, 11:59pm UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/37 "2013-06-03T23:59:26Z")
> [@reef\_shark](#): > > Radiometric dating (especially the methods your cite mentions) are based on several inherent assumptions. Yes, radiometric dating is based on several inherent assumptions. But if those assumptions weren’t true, atomic physics as we know it wouldn’t work. So confidence in the validity of radiometric dating not unreasonably remains pretty high. ---
**Author:** ![dropzone](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/dropzone/32/7515_2.png) [@dropzone](https://boards.straightdope.com/u/dropzone)\ **Post date:** [June 4, 2013, 12:23am UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/38 "2013-06-04T00:23:20Z")
> [@reef\_shark](#): > > Its not about what is ‘conceivable’. Somebody? ANYbody? Oh, well. [![](http://www.coffee-monster.com/wp-content/uploads/2013/04/inconceivable.jpg) ](http://www.coffee-monster.com/wp-content/uploads/2013/04/inconceivable.jpg) ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 4, 2013, 12:57am UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/39 "2013-06-04T00:57:34Z")
> [@reef\_shark](#): > > Also, not all the water came from rain, as that same section claims, but also from the fountains of the deep. But, unless you mean deep-sea thermal vents, which would not figure in the Flood story, there are no “fountains of the deep”. Ask any geologist. ---
**Author:** ![BrainGlutton](https://avatars.discourse-cdn.com/v4/letter/b/82dd89/32.png) [@BrainGlutton](https://boards.straightdope.com/u/BrainGlutton)\ **Post date:** [June 4, 2013, 1:26am UTC](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054/40 "2013-06-04T01:26:20Z")
BTW, as long as we’re on Flood-related matters, check out the [Lunar bukkake hypothesis](http://rationalwiki.org/wiki/Lunar_bukkake_hypothesis)! [Previous page](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054.md?page=1) [Next page](https://boards.straightdope.com/t/symbiosis-does-not-develop-over-time/660054.md?page=3)