Organism

Life on Earth
Temporal range: Late Hadean (?) – Recent
EscherichiaColi NIAID.jpg
These Escherichia coli cells provide an example of a prokaryotic microorganism
Scientific classification
(unranked):Life on Earth
Phylogenetic tree of life (Carl Woese). Viruses do not appear here because there is no evidence of how they relate to the other three kingdoms of life.

An organism is any individual living thing. It is easy to recognize a living thing, but not so easy to define it. Animals and plants are organisms, obviously. Organisms are a biotic, or living, part of the environment. Rocks and sunshine are parts of the non-living environment.

Organisms usually have five basic needs, to continue their metabolism They need air, water, nutrients (food), energy and a place to live. However, not all living things need all these at the same time. Many organisms do not need access to air at all.

A little thought is needed about viruses. There is no agreement as to whether they should be regarded as living. They are made of protein and nucleic acid, and they evolve, which is a really important fact. However, they exist in two quite different phases. One phase is dormant, not active. The other is inside a living cell of some other organism. Then the virus is very active reproducing itself. Consider the parallel with a computer program. When in use it is active; when it is not, it is completely inactive. It is still a program all the same.

Another example from biology is the spore, which is a distribution phase of a bacteria, fungus or some plants. They are not active until they get to the right situation. They have all the working parts to build a complete organism, but for the moment it is switched off.

Some organisms are made up of millions of cells. They are multicellular organisms. Many can be seen without using a microscope.

Most organisms are so small that they cannot be seen with the naked eye. You need a microscope to see them. They are called microorganisms. Organisms can be made up of just one cell. They are called unicellular organisms or single celled organisms. Examples include bacteria, and protozoa such as the Amoeba and Paramecium.

The project which works on the relationships between living things is the Tree of Life project; identifying a LUCA (last universal common ancestor) is one of its main aims. The LUCA is estimated to have lived some 3.8 billion years ago (sometime in the Palaeoarchaean era).[1][2]

A universal common ancestor is at least 102860 times more probable than having multiple ancestors.[3]
A model with a single common ancestor but allowing for some gene swapping among species was... 103489 times more probable than the best multi-ancestor model...[3]

The idea came from Charles Darwin's On the Origin of Species, "Therefore... probably all the organic beings which have ever lived on this earth have descended from some one primordial form..."

References

  1. Doolittle, W.F. (2000), "Uprooting the tree of life" (PDF), Scientific American, 282 (6): 90–95, doi:10.1038/scientificamerican0200-90, 10710791.
  2. Glansdorff, N.; Xu, Y; Labedan, B. (2008), "The last universal common ancestor: emergence, constitution and genetic legacy of an elusive forerunner", Biology Direct, 3: 29, doi:10.1186/1745-6150-3-29, PMC 2478661, 18613974.
  3. 3.0 3.1 Hesman Saey, T. (2010). "All modern life on Earth derived from common ancestor". Discovery News.
Other Languages
Afrikaans: Organisme
Alemannisch: Lebewesen
العربية: كائن حي
aragonés: Organismo
armãneashti: Hiințâ
অসমীয়া: জীৱ
asturianu: Ser vivu
azərbaycanca: Orqanizm
تۆرکجه: جانلی‌لار
বাংলা: জীব
Bân-lâm-gú: Sèⁿ-miā-thé
башҡортса: Организм
беларуская: Арганізм
беларуская (тарашкевіца)‎: Арганізм
български: Организъм
Boarisch: Lebewesn
буряад: Махабад
català: Organisme
čeština: Organismus
Cymraeg: Organeb byw
dansk: Organisme
Deutsch: Lebewesen
eesti: Organism
English: Organism
español: Ser vivo
Esperanto: Organismo
estremeñu: Organismu
euskara: Organismo
فارسی: جاندار
Frysk: Organisme
Gaelg: Bioag
galego: Ser vivo
客家語/Hak-kâ-ngî: Sâng-vu̍t
한국어: 생물
հայերեն: Օրգանիզմ
हिन्दी: जीव
hrvatski: Organizam
Ilokano: Organismo
Bahasa Indonesia: Makhluk hidup
interlingua: Organismo
isiXhosa: I-organism
íslenska: Lífvera
עברית: אורגניזם
Basa Jawa: Organisme
ಕನ್ನಡ: ಸಾವಯವ
ქართული: ორგანიზმი
қазақша: Ағза
Kiswahili: Kiumbehai
Kreyòl ayisyen: Òganis
kurdî: Endamwer
Кыргызча: Организм
Latina: Organismus
latviešu: Organisms
Lëtzebuergesch: Liewewiesen
lietuvių: Organizmas
la .lojban.: jmive
magyar: Élőlény
македонски: Организам
Malagasy: Zavamanan'aina
മലയാളം: ജീവി
मराठी: सजीव
მარგალური: ორგანიზმი
Bahasa Melayu: Organisma
Mìng-dĕ̤ng-ngṳ̄: Sĕng-ŭk
မြန်မာဘာသာ: သက်ရှိရုပ်စု
Nederlands: Organisme
नेपाल भाषा: प्राणी
日本語: 生物
Napulitano: Organismo
Nordfriisk: Organismus
norsk: Organisme
norsk nynorsk: Organisme
oʻzbekcha/ўзбекча: Organizm
ਪੰਜਾਬੀ: ਪ੍ਰਾਣੀ
پنجابی: آرگنزم
Papiamentu: Organismo
Patois: Aaganizim
Plattdüütsch: Organismus (Biologie)
polski: Organizm
português: Organismo
Qaraqalpaqsha: Organizm
română: Organism
Runa Simi: Kawsaq
русиньскый: Орґанізм
русский: Организм
саха тыла: Организм
Scots: Organism
sicilianu: Urganismu
සිංහල: ජීවීයෝ
سنڌي: آرگن ازم
slovenčina: Živá bytosť
slovenščina: Organizem
کوردی: ئۆرگانیزم
српски / srpski: Организам
srpskohrvatski / српскохрватски: Organizam
Basa Sunda: Organismeu
suomi: Eliö
svenska: Organism
Tagalog: Organismo
தமிழ்: உயிரினம்
татарча/tatarça: Организм
తెలుగు: జీవి
тоҷикӣ: Организм
ᏣᎳᎩ: ᎬᏃᏗ
Türkçe: Canlı
Türkmençe: Organizm
українська: Організм
اردو: عضویہ
Vahcuengh: Swnghvuz
Tiếng Việt: Sinh vật
Võro: Elolinõ
文言: 生物
West-Vlams: Organisme
Winaray: Organismo
吴语: 生物
ייִדיש: ארגאניזם
粵語: 生物
Zazaki: Gani
žemaitėška: Uorganėzmos
中文: 生物
ГӀалгӀай: Организм