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New page: Image:lighterstill.jpgright|frame The term "organism" (Greek ''ὀργανισμός'' - ''organismos'', from Ancient Greek ''ὄργανο...
[[Image:lighterstill.jpg]][[Image:Organism,_2005_96_x_77_inches.jpg|right|frame]]
The term "organism" (Greek ''ὀργανισμός'' - ''organismos'', from Ancient Greek ''ὄργανον'' - ''organon'' "organ, instrument, tool") first appeared in the English language in 1701 and took on its current definition by 1834 ([[Oxford English Dictionary]]).
Chambers Online Reference provides a broad definition: "any living [[structure]], such as a plant, animal, fungus or bacterium, capable of growth and reproduction".
==Biologic==
In [[biology]], an '''organism''' is any living [[thing]] (such as animal, plant, fungus, or micro-organism). In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of [[homeostasis]] as a stable whole. An organism may either be unicellular (single-celled) or be composed of, as in humans, many billions of cells grouped into specialized tissues and organs. The term ''[[multicellular]]'' (many-celled) describes any organism made up of more than one cell.
Organisms may be divided into the [[prokaryotic]] and [[eukaryotic]] groups. The prokaryotes represent two separate domains, the [[Bacteria]] and [[Archaea]]. All fungi, animals and plants are eukaryotes.
The word "'''''organism'''''" may broadly be defined as ''an assembly of [[molecules]] that function as a more or less stable whole and has the properties of life.'' However, many sources propose definitions that exclude [[virus]]es and theoretically-possible man-made non-organic life forms. [[Virus]]es are dependent on the biochemical machinery of a host cell for reproduction.
In multicellular life the word "organism" usually describes the whole [[hierarchy|hierarchical]] assemblage of systems (for example [[circulatory]], [[digestive]], or [[reproductive]]) themselves collections of organs; these are, in turn, collections of tissues, which are themselves made of [[cell]]s. In some plants and the [[nematode]] ''[[Caenorhabditis elegans]]'', individual cells are [[totipotent]].
===Viruses===
Viruses are not typically considered to be organisms because they are incapable of "independent" [[reproduction]] or [[metabolism]]. This controversy is problematic, though, since some [[parasite]]s and [[endosymbiont]]s are also incapable of independent life. Although viruses have a few [[enzyme]]s and molecules characteristic of living organisms, they are incapable of reproducing outside a host cell and most of their metabolic processes require a host and its 'genetic machinery' such as [[organelle]]s in eukaryotic hosts and the assemblage of ready-made enzymes (which the virus cannot make by itself) in prokaryotic hosts. While viruses sustain no independent [[metabolism]], and thus are usually not accounted organisms, they do have their own [[gene]]s and they do [[evolution|evolve]] by the same mechanisms by which organisms evolve.
===Superorganism===
A [[Superuniverse|superorganism]] is an organism consisting of many [[individual]]s working together as a single functional or social unit. Ants, and other eusocial invertebrates such as termites, are examples of superorganisms that form large colonies of individuals with highly specialised roles and [[division of labor]]. Individuals may be unable to reproduce or to survive for extended periods of time when separated from the colony. By working cooperatively, superorganisms can achieve feats that comparable solitary organisms cannot. Thermoregulation, for example, does not occur in individuals or small groups of honeybees or other invertebrates, but colonies of bees with more than about 5000 individuals can thermoregulate.[http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B6T2P-4867WXH-110-2&_cdi=4924&_user=4385511&_check=y&_orig=search&_coverDate=12%2F31%2F1983&_qd=1&view=c&wchp=dGLbVlz-zSkWW&md5=d23bd1cec870de7f5a44f8a2f367ed9c&ie=/sdarticle.pdf]
[[James Lovelock]], with his "[[Gaia Theory]]" has paralleled the work of [[Vladimir Vernadsky]], who suggested the whole of the [[biosphere]] in some respects can be considered as a superorganism.
The concept of superorganism is under dispute, as many [[biology|biologists]] maintain that in order for a social unit to be considered an organism by itself, the individuals should be in permanent physical connection to each other, and its [[evolution]] should be governed by selection to the whole society instead of individuals. While it's generally accepted that the society of eusocial animals is a unit of [[natural selection]] to at least some extent, most evolutionists claim that the individuals are still the primary units of selection.
The question remains "What is to be considered ''the [[individualism|individual]]''?". [[Evolution|Advocates of evolution]] like [[Richard Dawkins]] suggest that the individual selected is the "Selfish Gene". Others believe it is the whole genome of an organism. [[E.O. Wilson]] has shown that with ant-colonies and other social insects it is the breeding entity of the colony that is selected, and not its individual members. This could apply to the bacterial members of a stromatolite, which, because of genetic sharing, in some way comprise a single [[gene pool]]. Gaian theorists like [[Lynn Margulis]] would argue this applies equally to the symbiogenesis of the bacterial underpinnings of the whole of the Earth.
It would appear, from computer [[simulation]]s like Daisyworld that biological selection occurs at multiple levels simultaneously.
It is also argued that humans are actually a superorganism that includes microorganisms such as [[bacteria]]. It is estimated that "the human intestinal microbiota is composed of 10x13th to 10x14th microorganisms whose collective [[genome]] ("microbiome") contains at least 100 times as many genes as our own[...] Our microbiome has significantly enriched metabolism of glycans, amino acids, and xenobiotics; methanogenesis; and 2-methyl-D-erythritol 4-phosphate pathway–mediated biosynthesis of vitamins and isoprenoids. Thus, humans are superorganisms whose metabolism represents an amalgamation of microbial and human attributes." [http://dx.doi.org/10.1126/science.1124234]. An [[NIH]]-coordinated and -funded effort is currently in progress to characterize the [[Human microbiome project|human microbiome]].[http://en.wikipedia.org/wiki/Organism]
==References==
# T.Cavalier-Smith (1987) The origin of eukaryote and archaebacterial cells, Annals of the New York Academy of Sciences 503, 17–54
# "organism". Oxford English Dictionary (online ed.). 2004.
# "organism". Chambers 21st Century Dictionary (online ed.). 1999.
# Southwick, Edward E. (1983). "The honey bee cluster as a homeothermic superorganism" (PDF). Comparative Biochemistry and Physiology 75A (4): 741–745. doi:10.1016/0300-9629(83)90434-6. http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B6T2P-4867WXH-110-2&_cdi=4924&_user=4385511&_check=y&_orig=search&_coverDate=12%2F31%2F1983&_qd=1&view=c&wchp=dGLbVlz-zSkWW&md5=d23bd1cec870de7f5a44f8a2f367ed9c&ie=/sdarticle.pdf. Retrieved on 2006-07-20.
# Gill S. R., et al. Science, 312, 1355-1359 (2006). http://dx.doi.org/10.1126/science.1124234
# The Universal Features of Cells on Earth in Chapter 1 of Molecular Biology of the Cell fourth edition, edited by Bruce Alberts (2002) published by Garland Science.
# Doolittle, W. Ford (February, 2000). Uprooting the tree of life. Scientific American 282 (6): 90–95.
# NCBI: "The Genetic Codes", Compiled by Andrzej (Anjay) Elzanowski and Jim Ostell
# Jukes TH, Osawa S, The genetic code in mitochondria and chloroplasts., Experientia. 1990 Dec 1;46(11-12):1117-26.
# NCBI: "The Genetic Codes", Compiled by Andrzej (Anjay) Elzanowski and Jim Ostell
# Jukes TH, Osawa S, The genetic code in mitochondria and chloroplasts., Experientia. 1990 Dec 1;46(11-12):1117-26.
# Genetic Code page in the NCBI Taxonomy section (Downloaded 27 April 2007.)
# Syoso Osawa (1995). Evolution of the Genetic Code. Oxford University Press. pp. 232. ISBN 978-0198547815.
# Evaluation of the Rate of Evolution in Natural Populations of Guppies (Poecilia reticulata) "[1]"
# Oklahoma State - Horizontal Gene Transfer
# esalenctr.org
# Gibsona, Daniel G., Gwynedd A. Benders, Kevin C. Axelroda, Jayshree Zaveria, Mikkel A. Algirea, Monzia Moodiea, Michael G. Montaguea, J. Craig Ventera, Hamilton O. Smith, and Clyde A. Hutchison III (2008). "One-step assembly in yeast of 25 overlapping DNA fragments to form a complete synthetic Mycoplasma genitalium genome". PNAS 105 (51): 20404-20409. http://www.pnas.org/content/105/51/20404.full.pdf.
==External links==
* [http://news.bbc.co.uk/1/hi/sci/tech/944790.stm BBCNews: 27 September, 2000, When slime is not so thick] Citat: "It means that some of the lowliest creatures in the plant and animal kingdoms, such as slime and amoeba, may not be as primitive as once thought"
** [http://www.spaceref.com/news/viewpr.html?pid=4742 SpaceRef.com, July 29, 1997: Scientists Discover Methane Ice Worms On Gulf Of Mexico Sea Floor]
*** [http://www.science.psu.edu/iceworms/iceworms.html The Eberly College of Science: Methane Ice Worms discovered on Gulf of Mexico Sea Floor] download Publication quality photos
** [http://www.sb-roscoff.fr/Ecophy/PDF/00-Fisher-NatWis.pdf Artikel, 2000: Methane Ice Worms: Hesiocaeca methanicola. Colonizing Fossil Fuel Reserves]
** [http://www.spaceref.com/news/viewnews.html?id=339 SpaceRef.com, May 04, 2001: Redefining "Life as We Know it"] ''Hesiocaeca methanicola'' In 1997, Charles Fisher, professor of biology at Penn State, discovered this remarkable creature living on mounds of methane ice under half a mile of ocean on the floor of the Gulf of Mexico.
* [http://news.bbc.co.uk/1/hi/sci/tech/2585235.stm BBCNews, 18 December, 2002, 'Space bugs' grown in lab] Citat: "''Bacillus simplex'' and ''Staphylococcus pasteuri''...''Engyodontium album'' The strains cultured by Dr Wainwright seemed to be resistant to the effects of UV - one quality required for survival in space"
* [http://news.bbc.co.uk/1/hi/sci/tech/3003946.stm BBCNews, 19 June, 2003, Ancient organism challenges cell evolution] Citat: "It appears that this organelle has been conserved in evolution from prokaryotes to eukaryotes, since it is present in both"
* [http://www.anselm.edu/homepage/jpitocch/genbios/bi04syllabsu03.html Interactive Syllabus for General Biology - BI 04, Saint Anselm College, Summer 2003]
* [http://www.personal.psu.edu/users/j/s/jsf165/Bio110.html Jacob Feldman: Stramenopila]
* [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Root NCBI Taxonomy entry: root] (rich)
* [http://www.anselm.edu/homepage/jpitocch/genbios/surveybi04.html Saint Anselm College: Survey of representatives of the major Kingdoms] Citat: "Number of kingdoms has not been resolved...Bacteria present a problem with their diversity...[[Protista]] present a problem with their diversity...",
* [http://www.species2000.org/ Species 2000 Indexing the world's known species]. Species 2000 has the objective of enumerating all known species of plants, animals, fungi and microbes on Earth as the baseline dataset for studies of global biodiversity. It will also provide a simple access point enabling users to link from here to other data systems for all groups of organisms, using direct species-links.
* [http://www.abc.net.au/science/news/enviro/EnviroRepublish_828525.htm The largest organism in the world may be a fungus carpeting nearly 10 square kilometers of an Oregon forest, and may be as old as 10500 years.]
* [http://tolweb.org/tree/phylogeny.html The Tree of Life].
*[http://www.scribd.com/doc/1016/Life-from-birth-to-death/ Frequent questions from kids about life and their answers]
[[Category: General Reference]]
[[Category: Biology]]
The term "organism" (Greek ''ὀργανισμός'' - ''organismos'', from Ancient Greek ''ὄργανον'' - ''organon'' "organ, instrument, tool") first appeared in the English language in 1701 and took on its current definition by 1834 ([[Oxford English Dictionary]]).
Chambers Online Reference provides a broad definition: "any living [[structure]], such as a plant, animal, fungus or bacterium, capable of growth and reproduction".
==Biologic==
In [[biology]], an '''organism''' is any living [[thing]] (such as animal, plant, fungus, or micro-organism). In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of [[homeostasis]] as a stable whole. An organism may either be unicellular (single-celled) or be composed of, as in humans, many billions of cells grouped into specialized tissues and organs. The term ''[[multicellular]]'' (many-celled) describes any organism made up of more than one cell.
Organisms may be divided into the [[prokaryotic]] and [[eukaryotic]] groups. The prokaryotes represent two separate domains, the [[Bacteria]] and [[Archaea]]. All fungi, animals and plants are eukaryotes.
The word "'''''organism'''''" may broadly be defined as ''an assembly of [[molecules]] that function as a more or less stable whole and has the properties of life.'' However, many sources propose definitions that exclude [[virus]]es and theoretically-possible man-made non-organic life forms. [[Virus]]es are dependent on the biochemical machinery of a host cell for reproduction.
In multicellular life the word "organism" usually describes the whole [[hierarchy|hierarchical]] assemblage of systems (for example [[circulatory]], [[digestive]], or [[reproductive]]) themselves collections of organs; these are, in turn, collections of tissues, which are themselves made of [[cell]]s. In some plants and the [[nematode]] ''[[Caenorhabditis elegans]]'', individual cells are [[totipotent]].
===Viruses===
Viruses are not typically considered to be organisms because they are incapable of "independent" [[reproduction]] or [[metabolism]]. This controversy is problematic, though, since some [[parasite]]s and [[endosymbiont]]s are also incapable of independent life. Although viruses have a few [[enzyme]]s and molecules characteristic of living organisms, they are incapable of reproducing outside a host cell and most of their metabolic processes require a host and its 'genetic machinery' such as [[organelle]]s in eukaryotic hosts and the assemblage of ready-made enzymes (which the virus cannot make by itself) in prokaryotic hosts. While viruses sustain no independent [[metabolism]], and thus are usually not accounted organisms, they do have their own [[gene]]s and they do [[evolution|evolve]] by the same mechanisms by which organisms evolve.
===Superorganism===
A [[Superuniverse|superorganism]] is an organism consisting of many [[individual]]s working together as a single functional or social unit. Ants, and other eusocial invertebrates such as termites, are examples of superorganisms that form large colonies of individuals with highly specialised roles and [[division of labor]]. Individuals may be unable to reproduce or to survive for extended periods of time when separated from the colony. By working cooperatively, superorganisms can achieve feats that comparable solitary organisms cannot. Thermoregulation, for example, does not occur in individuals or small groups of honeybees or other invertebrates, but colonies of bees with more than about 5000 individuals can thermoregulate.[http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B6T2P-4867WXH-110-2&_cdi=4924&_user=4385511&_check=y&_orig=search&_coverDate=12%2F31%2F1983&_qd=1&view=c&wchp=dGLbVlz-zSkWW&md5=d23bd1cec870de7f5a44f8a2f367ed9c&ie=/sdarticle.pdf]
[[James Lovelock]], with his "[[Gaia Theory]]" has paralleled the work of [[Vladimir Vernadsky]], who suggested the whole of the [[biosphere]] in some respects can be considered as a superorganism.
The concept of superorganism is under dispute, as many [[biology|biologists]] maintain that in order for a social unit to be considered an organism by itself, the individuals should be in permanent physical connection to each other, and its [[evolution]] should be governed by selection to the whole society instead of individuals. While it's generally accepted that the society of eusocial animals is a unit of [[natural selection]] to at least some extent, most evolutionists claim that the individuals are still the primary units of selection.
The question remains "What is to be considered ''the [[individualism|individual]]''?". [[Evolution|Advocates of evolution]] like [[Richard Dawkins]] suggest that the individual selected is the "Selfish Gene". Others believe it is the whole genome of an organism. [[E.O. Wilson]] has shown that with ant-colonies and other social insects it is the breeding entity of the colony that is selected, and not its individual members. This could apply to the bacterial members of a stromatolite, which, because of genetic sharing, in some way comprise a single [[gene pool]]. Gaian theorists like [[Lynn Margulis]] would argue this applies equally to the symbiogenesis of the bacterial underpinnings of the whole of the Earth.
It would appear, from computer [[simulation]]s like Daisyworld that biological selection occurs at multiple levels simultaneously.
It is also argued that humans are actually a superorganism that includes microorganisms such as [[bacteria]]. It is estimated that "the human intestinal microbiota is composed of 10x13th to 10x14th microorganisms whose collective [[genome]] ("microbiome") contains at least 100 times as many genes as our own[...] Our microbiome has significantly enriched metabolism of glycans, amino acids, and xenobiotics; methanogenesis; and 2-methyl-D-erythritol 4-phosphate pathway–mediated biosynthesis of vitamins and isoprenoids. Thus, humans are superorganisms whose metabolism represents an amalgamation of microbial and human attributes." [http://dx.doi.org/10.1126/science.1124234]. An [[NIH]]-coordinated and -funded effort is currently in progress to characterize the [[Human microbiome project|human microbiome]].[http://en.wikipedia.org/wiki/Organism]
==References==
# T.Cavalier-Smith (1987) The origin of eukaryote and archaebacterial cells, Annals of the New York Academy of Sciences 503, 17–54
# "organism". Oxford English Dictionary (online ed.). 2004.
# "organism". Chambers 21st Century Dictionary (online ed.). 1999.
# Southwick, Edward E. (1983). "The honey bee cluster as a homeothermic superorganism" (PDF). Comparative Biochemistry and Physiology 75A (4): 741–745. doi:10.1016/0300-9629(83)90434-6. http://www.sciencedirect.com/science?_ob=MiamiImageURL&_imagekey=B6T2P-4867WXH-110-2&_cdi=4924&_user=4385511&_check=y&_orig=search&_coverDate=12%2F31%2F1983&_qd=1&view=c&wchp=dGLbVlz-zSkWW&md5=d23bd1cec870de7f5a44f8a2f367ed9c&ie=/sdarticle.pdf. Retrieved on 2006-07-20.
# Gill S. R., et al. Science, 312, 1355-1359 (2006). http://dx.doi.org/10.1126/science.1124234
# The Universal Features of Cells on Earth in Chapter 1 of Molecular Biology of the Cell fourth edition, edited by Bruce Alberts (2002) published by Garland Science.
# Doolittle, W. Ford (February, 2000). Uprooting the tree of life. Scientific American 282 (6): 90–95.
# NCBI: "The Genetic Codes", Compiled by Andrzej (Anjay) Elzanowski and Jim Ostell
# Jukes TH, Osawa S, The genetic code in mitochondria and chloroplasts., Experientia. 1990 Dec 1;46(11-12):1117-26.
# NCBI: "The Genetic Codes", Compiled by Andrzej (Anjay) Elzanowski and Jim Ostell
# Jukes TH, Osawa S, The genetic code in mitochondria and chloroplasts., Experientia. 1990 Dec 1;46(11-12):1117-26.
# Genetic Code page in the NCBI Taxonomy section (Downloaded 27 April 2007.)
# Syoso Osawa (1995). Evolution of the Genetic Code. Oxford University Press. pp. 232. ISBN 978-0198547815.
# Evaluation of the Rate of Evolution in Natural Populations of Guppies (Poecilia reticulata) "[1]"
# Oklahoma State - Horizontal Gene Transfer
# esalenctr.org
# Gibsona, Daniel G., Gwynedd A. Benders, Kevin C. Axelroda, Jayshree Zaveria, Mikkel A. Algirea, Monzia Moodiea, Michael G. Montaguea, J. Craig Ventera, Hamilton O. Smith, and Clyde A. Hutchison III (2008). "One-step assembly in yeast of 25 overlapping DNA fragments to form a complete synthetic Mycoplasma genitalium genome". PNAS 105 (51): 20404-20409. http://www.pnas.org/content/105/51/20404.full.pdf.
==External links==
* [http://news.bbc.co.uk/1/hi/sci/tech/944790.stm BBCNews: 27 September, 2000, When slime is not so thick] Citat: "It means that some of the lowliest creatures in the plant and animal kingdoms, such as slime and amoeba, may not be as primitive as once thought"
** [http://www.spaceref.com/news/viewpr.html?pid=4742 SpaceRef.com, July 29, 1997: Scientists Discover Methane Ice Worms On Gulf Of Mexico Sea Floor]
*** [http://www.science.psu.edu/iceworms/iceworms.html The Eberly College of Science: Methane Ice Worms discovered on Gulf of Mexico Sea Floor] download Publication quality photos
** [http://www.sb-roscoff.fr/Ecophy/PDF/00-Fisher-NatWis.pdf Artikel, 2000: Methane Ice Worms: Hesiocaeca methanicola. Colonizing Fossil Fuel Reserves]
** [http://www.spaceref.com/news/viewnews.html?id=339 SpaceRef.com, May 04, 2001: Redefining "Life as We Know it"] ''Hesiocaeca methanicola'' In 1997, Charles Fisher, professor of biology at Penn State, discovered this remarkable creature living on mounds of methane ice under half a mile of ocean on the floor of the Gulf of Mexico.
* [http://news.bbc.co.uk/1/hi/sci/tech/2585235.stm BBCNews, 18 December, 2002, 'Space bugs' grown in lab] Citat: "''Bacillus simplex'' and ''Staphylococcus pasteuri''...''Engyodontium album'' The strains cultured by Dr Wainwright seemed to be resistant to the effects of UV - one quality required for survival in space"
* [http://news.bbc.co.uk/1/hi/sci/tech/3003946.stm BBCNews, 19 June, 2003, Ancient organism challenges cell evolution] Citat: "It appears that this organelle has been conserved in evolution from prokaryotes to eukaryotes, since it is present in both"
* [http://www.anselm.edu/homepage/jpitocch/genbios/bi04syllabsu03.html Interactive Syllabus for General Biology - BI 04, Saint Anselm College, Summer 2003]
* [http://www.personal.psu.edu/users/j/s/jsf165/Bio110.html Jacob Feldman: Stramenopila]
* [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Root NCBI Taxonomy entry: root] (rich)
* [http://www.anselm.edu/homepage/jpitocch/genbios/surveybi04.html Saint Anselm College: Survey of representatives of the major Kingdoms] Citat: "Number of kingdoms has not been resolved...Bacteria present a problem with their diversity...[[Protista]] present a problem with their diversity...",
* [http://www.species2000.org/ Species 2000 Indexing the world's known species]. Species 2000 has the objective of enumerating all known species of plants, animals, fungi and microbes on Earth as the baseline dataset for studies of global biodiversity. It will also provide a simple access point enabling users to link from here to other data systems for all groups of organisms, using direct species-links.
* [http://www.abc.net.au/science/news/enviro/EnviroRepublish_828525.htm The largest organism in the world may be a fungus carpeting nearly 10 square kilometers of an Oregon forest, and may be as old as 10500 years.]
* [http://tolweb.org/tree/phylogeny.html The Tree of Life].
*[http://www.scribd.com/doc/1016/Life-from-birth-to-death/ Frequent questions from kids about life and their answers]
[[Category: General Reference]]
[[Category: Biology]]