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Clownfish amid sea anemone tentacles
.The term symbiosis (from the Greek: σύν syn "with"; and βίωσις biosis "living") commonly describes close and often long-term interactions between different biological species.^ The word symbiosis was coined in 1879 by the German botanist, Heinrich De Bary, to describe how different species of plants and animals associate with each other (Milne, Milne, & Russel, undated).

^ The new experiments reported here show that this effect applies not just in genetically related organisms but may also occur from symbiosis between distinct species.

^ Man-computer symbiosis is an expected development in cooperative interaction between men and electronic computers.
  • Man-Computer Symbiosis 21 January 2010 4:04 UTC groups.csail.mit.edu [Source type: FILTERED WITH BAYES]

The term was first used in 1879 by the German mycologist Heinrich Anton de Bary, who defined it as "the living together of unlike organisms."[1][2] The definition of symbiosis is in flux, and the term has been applied to a wide range of biological interactions. .The symbiotic relationship may be categorized as mutualistic, commensal, or parasitic in nature.^ A third symbiotic relationship, called commensalism , is one that is beneficial only to one member.

^ Conversely we also can look at the relationships in our lives that have the nature of a host-parasite relationship.

^ What reasons can you give that would indicate that this is a mutualistic symbiotic relationship?
  • Fungi and Insect Symbiosis 21 January 2010 4:04 UTC www.botany.hawaii.edu [Source type: FILTERED WITH BAYES]

[3][4] .Others define it more narrowly, as only those relationships from which both organisms benefit, in which case it would be synonymous with mutualism.^ Mutualism: A relationship between two organisms (host and symbiont) in which both benefit from the interaction.
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^ There are many types of symbiosis, including mutualism (in which both organisms benefit), commensalism (in which one organism benefits and the other is not affected), or parasitism (in which one organism benefits at the other organism's expense).
  • Plant Glossary: S - EnchantedLearning.com 21 January 2010 4:04 UTC www.enchantedlearning.com [Source type: FILTERED WITH BAYES]

^ This would show the effect to be relevant to symbiosis between genetically unrelated organisms and therefore more widely applicable in nature.

[1][5][6]
.Symbiotic relationships include those associations in which one organism lives on another (ectosymbiosis, such as mistletoe), or where one partner lives inside the other (endosymbiosis, such as lactobacilli and other bacteria in humans or zooxanthelles in corals).^ For the process to be identified as such, a symbiotic relationship has to be recognised in which at least one partner has acquired at least one trait that was previously exclusive to the other partner.

^ If psychology is multi-dimensional and human behavior is multi-dimensional or complex, does it not benefit psychology to have differing philosophical approaches as one may be better for one situation, and the other approach may be better suited in an altogether different situation?
  • PSY 260: Symbiosis and the scientific method REDUX « Dr. Christopher H. Ramey's Course Blog 21 January 2010 4:04 UTC christopherramey.wordpress.com [Source type: FILTERED WITH BAYES]

^ In so doing, this effect also shows how the characteristics of an organism can be induced in another symbiotic organism without direct transfer of genetic material.

.Symbiotic relationships may be either obligate, i.e., necessary for the survival of at least one of the organisms involved, or facultative, where the relationship is beneficial but not essential for survival of the organisms.^ If so, then the relationship is one of continuous and obligate mutualism.

^ However, we used only one population of organisms and thus, in general, the symbionts may have been closely genetically related (by inheritance).

^ One of the most important drives that may lead to such a relationship is the inability of animals to digest cellulose.
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[7][8]

Contents

Physical interaction

Alder tree root nodule
.Endosymbiosis is any symbiotic relationship in which one symbiont lives within the tissues of the other, either in the intracellular space or extracellularly.^ One of the most important driving forces that result in symbiotic relationships between microorganisms is the inability of animals to digest cellulose.
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^ Parasitism: A relationship between two organisms in which one organism benefits at the other organism's expense.
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^ At the same time consciousness must keep one eye on the unconscious and the other focussed just as clearly on the potentialities of human existence and human relationships.

[8][9] .Examples are rhizobia, nitrogen-fixing bacteria that live in root nodules on legume roots; actinomycete nitrogen-fixing bacteria called Frankia, which live in alder tree root nodules; single-celled algae inside reef-building corals; and bacterial endosymbionts that provide essential nutrients to about 10%–15% of insects.^ Review Genomes of the symbiotic nitrogen-fixing bacteria of legumes.
  • How CYCLOPS keeps an eye on plant symbiosis 21 January 2010 4:04 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Example: Algae called zooxanthellae that often live inside the tissue of a coral.
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^ The larva of the insect lives in the ovary of the fig tree, and there it gets its food.
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.Ectosymbiosis, also referred to as exosymbiosis, is any symbiotic relationship in which the symbiont lives on the body surface of the host, including the inner surface of the digestive tract or the ducts of exocrine glands.^ Mutualism: A relationship between two organisms (host and symbiont) in which both benefit from the interaction.
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^ One of the most important driving forces that result in symbiotic relationships between microorganisms is the inability of animals to digest cellulose.
  • Fungi and Insect Symbiosis 21 January 2010 4:04 UTC www.botany.hawaii.edu [Source type: FILTERED WITH BAYES]

^ Two species living together in a symbiotic relationship can be mutually benefited in the areas of food, shelter, substratum, or transport.

[8][10] Examples of this include ectoparasites such as lice, commensal ectosymbionts such as the barnacles that attach themselves to the jaw of baleen whales, and mutualist ectosymbionts such as cleaner fish.

Mutualism

Hermit crab, Calcinus laevimanus, with sea anemone.
.The term "mutualism" describes any relationship between individuals of different species where both individuals derive a benefit.^ Mutualism: A relationship between two organisms (host and symbiont) in which both benefit from the interaction.
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^ There are many types of symbiosis, including mutualism (in which both organisms benefit), commensalism (in which one organism benefits and the other is not affected), or parasitism (in which one organism benefits at the other organism's expense).
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^ In the second phase, after an ecosystem of mutually beneficial organisms has become established, the evolution of the individual organisms therein operates in a different environment.

[11] .Generally, only lifelong interactions involving close physical and biochemical contact can properly be considered symbiotic.^ However, we used only one population of organisms and thus, in general, the symbionts may have been closely genetically related (by inheritance).

.Mutualistic relationships may be either obligate for both species, obligate for one but facultative for the other, or facultative for both.^ If so, then the relationship is one of continuous and obligate mutualism.

^ If psychology is multi-dimensional and human behavior is multi-dimensional or complex, does it not benefit psychology to have differing philosophical approaches as one may be better for one situation, and the other approach may be better suited in an altogether different situation?
  • PSY 260: Symbiosis and the scientific method REDUX « Dr. Christopher H. Ramey's Course Blog 21 January 2010 4:04 UTC christopherramey.wordpress.com [Source type: FILTERED WITH BAYES]

^ There are many types of symbiosis, including mutualism (in which both organisms benefit), commensalism (in which one organism benefits and the other is not affected), or parasitism (in which one organism benefits at the other organism's expense).
  • Plant Glossary: S - EnchantedLearning.com 21 January 2010 4:04 UTC www.enchantedlearning.com [Source type: FILTERED WITH BAYES]

.Many biologists restrict the definition of symbiosis to close mutualist relationships.^ Symbiosis: A close relationship between two organisms.
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^ The scientists we will encounter in the next two lessons have been studying different organisms that participate in “symbiosis.” : The scientists we will encounter in the next two lessons have been studying different organisms that participate in “symbiosis.” Symbiosis: A close relationship between two organisms.
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A Spur-winged Plover picking the teeth of a Nile crocodile
.A large percentage of herbivores have mutualistic gut fauna that help them digest plant matter, which is more difficult to digest than animal prey.^ Much more time went into finding or obtaining information than into digesting it.
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^ We will look at some examples of animal-fungi symbiosis, or more specifically, insect-fungi symbiosis, which I think are far more interesting than the above examples.
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^ "Mechanical extension" has given way to replacement of men, to automation, and the men who remain are there more to help than to be helped.
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[7] .Coral reefs are the result of mutualisms between coral organisms and various types of algae that live inside them.^ There are many types of symbiosis, including mutualism (in which both organisms benefit), commensalism (in which one organism benefits and the other is not affected), or parasitism (in which one organism benefits at the other organism's expense).
  • Plant Glossary: S - EnchantedLearning.com 21 January 2010 4:04 UTC www.enchantedlearning.com [Source type: FILTERED WITH BAYES]

^ What does this mean for organisms that live symbiotically and can perform both photosynthesis (zooxanthellae) and respiration (zooxanthellae and coral)?
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^ Slide41 : In the next two lessons we will learn more about symbiotic relationships by looking at actual research being conducting by scientists on coral reef organisms.
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[12] .Most land plants and land ecosystems rely on mutualisms between the plants, which fix carbon from the air, and mycorrhyzal fungi, which help in extracting minerals from the ground.^ Plants enter a symbiosis with fungi of the taxonomic group Glomeromycota, which facilitates phosphate and mineral acquisition ( 2 , 3 ).
  • How CYCLOPS keeps an eye on plant symbiosis 21 January 2010 4:04 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Most fungi and a few flowering plants (like some orchids and Indian pipe) are saprophytic.
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[13]
.An example of mutual symbiosis is the relationship between the ocellaris clownfish that dwell among the tentacles of Ritteri sea anemones.^ An example of this kind of relationship is the sea anemone that grows on the shell of the hermit crab.

^ Enzyme distribution and metabolite exchange in the symbiosis between the deep-sea tube worm, Riftia pachyptila , and its bacterial endosymbiont G. Hervé and Z. Minic (Paris, France) .

^ We have previously described examples of symbiosis between fungi and photosynthetic organisms, i.e.
  • Fungi and Insect Symbiosis 21 January 2010 4:04 UTC www.botany.hawaii.edu [Source type: FILTERED WITH BAYES]

The territorial fish protects the anemone from anemone-eating fish, and in turn the stinging tentacles of the anemone protect the clownfish from its predators. A special mucus on the clownfish protects it from the stinging tentacles.[14]
Another example is the goby fish, which sometimes lives together with a shrimp. The shrimp digs and cleans up a burrow in the sand in which both the shrimp and the goby fish live. The shrimp is almost blind, leaving it vulnerable to predators when above ground. In case of danger the goby fish touches the shrimp with its tail to warn it. When that happens both the shrimp and goby fish quickly retract into the burrow.[15]
.One of the most spectacular examples of obligate mutualism is between the siboglinid tube worms and symbiotic bacteria that live at hydrothermal vents and cold seeps.^ If so, then the relationship is one of continuous and obligate mutualism.

^ Two species living together in a symbiotic relationship can be mutually benefited in the areas of food, shelter, substratum, or transport.

^ The ego and Self appear to form a symbiotic relationship of continuous and obligate mutualism.

.The worm has no digestive tract and is wholly reliant on its internal symbionts for nutrition.^ Our earlier experiments showed that when appropriate symbionts are reliably available, and incur no additional overheads, then there is no pressure to be independent.

The bacteria oxidize either hydrogen sulfide or methane which the host supplies to them. These worms were discovered in the late 1980s at the hydrothermal vents near the Galapagos Islands and have since been found at deep-sea hydrothermal vents and cold seeps in all of the world's oceans.[16]
.There are also many types of tropical and sub-tropical ants that have evolved very complex relationships with certain tree species.^ However, in this two-species model we expect a residual symbiotic partner to be more common and this type of relationship is easier to find.

[17]

Commensalism

Phoretic mites on a fly (Pseudolynchia canariensis).
.Commensalism describes a relationship between two living organisms where one benefits and the other is not significantly harmed or helped.^ Symbiosis: A close relationship between two organisms.
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^ Mutualism: A relationship between two organisms (host and symbiont) in which both benefit from the interaction.
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^ Parasitism: A relationship between two organisms in which one organism benefits at the other organism's expense.
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.It is derived from the English word commensal, meaning "sharing food" and used of human social interaction.^ The word entrainment is used to refer to any situation in which small interactions among the individuals of a system have the effect of confining the total state of the system to some limited region of the global state space.

^ My original post stated that it was a natural science because of the use of the scientific method and a social science because of the exploration of human society that is done through research.
  • PSY 260: Symbiosis and the scientific method REDUX « Dr. Christopher H. Ramey's Course Blog 21 January 2010 4:04 UTC christopherramey.wordpress.com [Source type: FILTERED WITH BAYES]

The word derives from the medieval Latin word, formed from com- and mensa, meaning "sharing a table".[11][18]
.Commensal relationships may involve one organism using another for transportation (phoresy) or for housing (inquilinism), or it may also involve one organism using something another created, after its death (metabiosis).^ However, we used only one population of organisms and thus, in general, the symbionts may have been closely genetically related (by inheritance).

^ This enabled us to show how the characteristics of one organism can be induced in another symbiotic organism.

^ The 20 traits of each organism may take one of three forms: correct, incorrect or neutral shown as 1, 0 and "-", respectively.

.Examples of metabiosis are hermit crabs using gastropod shells to protect their bodies and spiders building their webs on plants.^ An example of this kind of relationship is the sea anemone that grows on the shell of the hermit crab.

Parasitism

Flea bites on a human is an example of parasitism (the flea as parasite to the human host in this case).
.A parasitic relationship is one in which one member of the association benefits while the other is harmed.^ Parasitism: A relationship between two organisms in which one organism benefits at the other organism's expense.
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^ Commensal relationships can be mutalistic (not harmful to the other) or parasitic (harmful to the other) and can be continuous or intermittent.

^ If psychology is multi-dimensional and human behavior is multi-dimensional or complex, does it not benefit psychology to have differing philosophical approaches as one may be better for one situation, and the other approach may be better suited in an altogether different situation?
  • PSY 260: Symbiosis and the scientific method REDUX « Dr. Christopher H. Ramey's Course Blog 21 January 2010 4:04 UTC christopherramey.wordpress.com [Source type: FILTERED WITH BAYES]

[19] .Parasitic symbioses take many forms, from endoparasites that live within the host's body to ectoparasites that live on its surface.^ Evidence of this goodness includes increases in body weight, longevity, and several important chemicals for both parasite and host.

^ While trying to fight off the new oxygen breathers, the host organism ended up forming feedback links with the invader which allowed the host to live in an oxygen-rich atmosphere.

.In addition, parasites may be necrotrophic, which is to say they kill their host, or biotrophic, meaning they rely on their host's surviving.^ However, since the hosts and parasites are in separate populations the parasites will not be replaced by hosts (as they were in our original experiments).

^ In practice, it seems that the ratio is reliably higher-not going outside 40-60% in all 17 (of 20) runs of the experiment that exhibited a host/parasite split.

Biotrophic parasitism is an extremely successful mode of life. .Depending on the definition used, as many as half of all animals have at least one parasitic phase in their life cycles, and it is also frequent in plants and fungi.^ Many things come into play in a psychological approach, and I still believe there is not a rigid, one-size fits all approach.
  • PSY 260: Symbiosis and the scientific method REDUX « Dr. Christopher H. Ramey's Course Blog 21 January 2010 4:04 UTC christopherramey.wordpress.com [Source type: FILTERED WITH BAYES]

^ Scientists believe that zooxanthellae and other phytoplankton (often microscopic plants) in the ocean produce AT LEAST HALF of our Earth’s OXYGEN via photosynthesis.
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^ There can be no other way to study human or animal behavior using just one method.
  • PSY 260: Symbiosis and the scientific method REDUX « Dr. Christopher H. Ramey's Course Blog 21 January 2010 4:04 UTC christopherramey.wordpress.com [Source type: FILTERED WITH BAYES]

.Moreover, almost all free-living animals are host to one or more parasite taxa.^ In practice, it seems that the ratio is reliably higher-not going outside 40-60% in all 17 (of 20) runs of the experiment that exhibited a host/parasite split.

An example of a biotrophic relationship would be a tick feeding on the blood of its host.

Symbiosis and evolution

Leafhoppers protected by an army of meat ants
.While historically, symbiosis has received less attention than other interactions such as predation or competition,[20] it is increasingly recognised as an important selective force behind evolution,[7][21] with many species having a long history of interdependent co-evolution.^ If the organism interacts with many other organisms during its lifetime then its fitness will reflect the fitness of a set of points sampled from the neighborhood of its own characteristics.

^ Mutations in CYCLOPS are less penetrant than mutants in other Sym pathway components.
  • How CYCLOPS keeps an eye on plant symbiosis 21 January 2010 4:04 UTC www.ncbi.nlm.nih.gov [Source type: Academic]

^ Wallin (1927), for example, discussed the importance of symbiosis in the process of evolution and coined the term symbionticism which he proposed as "the fundamental factor or the cardinal principle in the origin of species" (p.

[22] .In fact, the evolution of all eukaryotes (plants, animals, fungi, and protists) is believed under the endosymbiotic theory to have resulted from a symbiosis between various sorts of bacteria.^ Addressing the topic of defensive mutualisms in microbial symbiosis across this wide spectrum, it includes chapters on defensive mutualistic associations involving multiple kingdoms of organisms in terrestrial and aquatic ecosystems--plant, animal, fungi, bacteria, and protozoans.
  • CRC Press Online - Book: Defensive Mutualism in Microbial Symbiosis 21 January 2010 4:04 UTC www.crcpress.com [Source type: Academic]

^ According to her theory, this cell was not the result of genetic mutation, or of survival of the fittest, but rather, of the process of feedback resulting from symbiosis (Margulis & Sagan, 1986).

^ For example, eukaryotes, which include all plants and animals, have a symbiogenic origin [Margulis 1992].

[7][23][24]

Symbiogenesis

.The biologist Lynn Margulis, famous for her work on endosymbiosis, contends that symbiosis is a major driving force behind evolution.^ The realization of the significance of microbial ecosystems for the health of our planet was a major component in the elaboration of the Gaia hypothesis by James Lovelock and Lynn Margulis.

^ Most biologists now agree with Margulis that evolution advanced rapidly when microbes coupled symbiotically in response to the production of oxygen in the atmosphere.

.She considers Darwin's notion of evolution, driven by competition, as incomplete and claims that evolution is strongly based on co-operation, interaction, and mutual dependence among organisms.^ In the second phase, after an ecosystem of mutually beneficial organisms has become established, the evolution of the individual organisms therein operates in a different environment.

^ We use the happenstance co-location of organisms to form groups since it makes minimal assumptions about the nature of symbiont interactions.

^ Mutualism: A relationship between two organisms (host and symbiont) in which both benefit from the interaction.
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According to Margulis and Dorion Sagan, "Life did not take over the globe by combat, but by networking."[25]

Co-evolution

.Symbiosis played a major role in the co-evolution of flowering plants and the animals that pollinate them.^ Modern cosmologists suggest that symbiosis played an important part in the evolution of our earth.

Many plants that are pollinated by insects, bats, or birds have highly specialized flowers modified to promote pollination by a specific pollinator that is also correspondingly adapted. The first flowering plants in the fossil record had relatively simple flowers. .Adaptive speciation quickly gave rise to many diverse groups of plants, and, at the same time, corresponding speciation occurred in certain insect groups.^ If many organisms go extinct at the same time, the fossil record wouldn't necessarily represent the rarer species and the more common equally.
  • Plant Glossary: S - EnchantedLearning.com 21 January 2010 4:04 UTC www.enchantedlearning.com [Source type: FILTERED WITH BAYES]

^ We evaluated individuals in the context of many randomly constructed groups of individuals and, instead of assigning fitness based on their individual ability, we gave them a fitness that reflected the average success of groups they formed.

^ One group supports the notion that plants and algae are the same thing and the other group will challenge this by mentioning any differences between the two.
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Some groups of plants developed nectar and large sticky pollen, while insects evolved more specialized morphologies to access and collect these rich food sources. .In some taxa of plants and insects the relationship has become dependent,[26] where the plant species can only be pollinated by one species of insect.^ The fig tree is pollinated only by the insect Blastophaga grossorun .
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[27]

Notes

  1. ^ a b Wilkinson 2001
  2. ^ Douglas 1994, p. 1
  3. ^ Dethlefsen L, McFall-Ngai M, Relman DA (2007). "An ecological and evolutionary perspective on human-microbe mutualism and disease". Nature 449: 811–808. doi:10.1038/nature06245. PMID 17943117. 
  4. ^ Paszkowski U. (2006). "Mutualism and parasitism: the yin and yang of plant symbioses". Curr Opin Plant Biol 9: 364–370. doi:10.1016/j.pbi.2006.05.008. PMID 16713732. 
  5. ^ Isaac 1992, p. 266
  6. ^ Saffo 1993
  7. ^ a b c d Moran 2006
  8. ^ a b c Ahmadjian & Paracer 2000, p. 12
  9. ^ Sapp 1994, p. 142
  10. ^ Nardon & Charles 2002
  11. ^ a b Ahmadjian & Paracer 2000, p. 6
  12. ^ Toller, Rowan & Knowlton 2001
  13. ^ Harrison 2005
  14. ^ Lee 2003
  15. ^ Facey, Helfman & Collette 1997
  16. ^ Cordes 2005
  17. ^ Piper, Ross (2007), Extraordinary Animals: An Encyclopedia of Curious and Unusual Animals, Greenwood Press.
  18. ^ Nair 2005
  19. ^ Ahmadjian & Paracer 2000, p. 7
  20. ^ Townsend, Begon & Harper 1996
  21. ^ Wernegreen 2004
  22. ^ Ahmadjian & Paracer 2000, p. 3-4
  23. ^ Brinkman 2002
  24. ^ Golding & Gupta 1995
  25. ^ Sagan & Margulis 1986
  26. ^ Harrison 2002
  27. ^ Danforth & Ascher 1997

See also

References

.

External links


Simple English

Symbiosis (pl. symbioses) means living together. It describes close and long-term relationships between different species. The term was coined by Anton de Bary in 1879,[1] after the nature of lichen was discovered.[2][3]

A symbiont is an organism living in a mutually beneficial relationship with another organism from a different species.[4] When one species lives inside another species, or a microscopic symbiont lives inside the cells of a host, it is called an endosymbiont.

The relevance of symbiosis is its frequency and its evolutionary significance. There appear to be no higher plants or animals without symbionts. Those symbionts are of great importance to the larger organisms, who in most cases would be unable to live as they do without their symbionts. Mycorrhiza in higher plants, bacteria in herbivores, and gut flora in humans are examples.

Furthermore, most of these associations are between organisms not just from different species, but from different kingdoms. And lastly, the cells of all eukaryotes contain organelles which are descendents of symbiotic relationships which began at least a billion years ago. Mitochondria and plastids are examples. The conclusion must be that symbiosis has been highly significant in the evolution of life.

Contents

Types of symbiosis

The various forms of symbiosis include:

Type 1: Partners keep their bodies separate

Symbiosis does not always benefit both partners. This is what may happen:

  • parasitism, in which the association has disadvantages for one of the two. One may even destroy or kill the other. (+ −)
  • mutualism, in which the association has advantages for both (+ +)
  • commensalism, in which one member of the association benefits while the other is not affected (+ 0)

Type 2: Partners live as one organism

This kind of symbiosis is called endosymbiosis. Examples are:

Almost for certain, this happened to form the eukaryote cell. That's the type of cell all animals and plants are made of. The organelles inside the cell, such as mitochondria and chloroplasts, contain some DNA. This DNA is the remnant of a once separate bacterium. The theory is that the eukaryote cell evolved by the fusion of several bacteria or archaea organisms.[6][7][8][9]

Examples of symbiosis

[[File:|thumb|200px|right|Clownfish in their sea anemone]]

File:Lotus pedunculatus11
Rhizobia bacteria in nodules fix nitrogen
  • An example of mutual symbiosis is the relationship between clownfish that live among the tentacles of tropical sea anemones. The clownfish protects the anemone from other fish, and the stinging tentacles of the anemone protect the anemone fish from its predators. A special mucus on the clownfish protects it from the stinging tentacles.
  • Another example is the goby fish, which sometimes lives together with a shrimp. The shrimp digs and cleans up a burrow in the sand in which both the shrimp and the goby fish live. The shrimp is almost blind, and is vulnerable to predators when above ground. When a predator approaches, the goby fish touches the shrimp with its tail as a signal. When that happens both the shrimp and goby fish quickly retreat into the burrow.
  • The famous relationship between the Egyptian Plover bird and the crocodile is a symbiosis. In this relationship, the bird picks off parasites that live in the crocodile's jaws. To that end, the crocodile opens its mouth to allow the bird to enter. For the bird's part, this relationship not only is a ready source of food, but a safe one considering that few predator species would dare strike at the bird at such close proximity to its host.
  • A lichen is an intimate combination of a fungus with an alga. The alga lives inside the fungus, which must have the alga to survive. The alga, on the other hand, can survive on its own. The result of the union is a flat, coloured lichen which grows on rocks and other surfaces in the open air.
  • Herbivores are host to gut bacteria which help them digest plant material. Plant cell walls are made of cellulose, and no animal has ever developed an enzyme to digest this material. Therefore, at least for herbivores which eat leaves, the bacteria are essential.
  • Some species of ants 'farm' aphids, protecting them from predators, and moving them from one feeding site to another. The ants consume the sweet sticky fluid which aphids secrete after sucking plant sap.

References

  1. de Bary, Anton 1879. Die Erscheinung der Symbiosis. In Verlag auf der Versammlung der Naturforscher und Artze zu Cassel. Strassburg.
  2. Schwendener, Simon 1868. Unter suchungen über den Flechtenthallus. Beiträge zur wissenschaftlichten Botanik 6, 195–207.
  3. Crombie J.M. 1886. On the algae-lichen hypothesis. J Linn. Soc. 21, 259–282.
  4. King R.C. Stansfield W.D. & Mulligan P.K. 2006. A dictionary of genetics, 7th ed. Oxford.
  5. Buchner P. 1965. Endosymbioses of animals with plant microorganisms. Wiley N.Y.
  6. Margulis, Lynn 1998. The symbiotic planet: a new look at evolution. Weidenfeld & Nicolson, London. Margulis believes symbiosis is the most important force in evolution.
  7. Sapp J. 1994. Evolution by association: a history of symbiosis. Oxford. A balanced overview.
  8. Khakhina L.N. 1992. Concepts of symbiogenesis: a historical and critical survey of the research of Russian botanists. Yale, New Haven CN.
  9. Lake, James A. Evidence for an early prokaryote symbiogenesis. Nature 460 967–971.


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Up to date as of December 30, 2010

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