Dictionary
a characteristic state or mode of living "social life" "city life" "real life" the experience of being alive the course of human events and activities "he could no longer cope with the complexities of life" the course of existence of an individual the actions and events that occur in living "he hoped for a new life in Australia" "he wanted to live his own life without interference from others" the condition of living or the state of being alive "while there's life there's hope" "life depends on many chemical and physical processes" the period during which something is functional (as between birth and death) "the battery had a short life" "he lived a long and happy life" the period between birth and the present time "I have known him all his life" the period from the present until death "he appointed himself emperor for life" a living person "his heroism saved a life" animation and energy in action or expression "it was a heavy play and the actors tried in vain to give life to it" living things collectively "the oceans are teeming with life" the organic phenomenon that distinguishes living organisms from nonliving ones "there is no life on the moon" an account of the series of events making up a person's life a motive for living "pottery was his life" a prison term lasting as long as the prisoner lives "he got life for killing the guard"
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Wikipedia
For other uses, see Life (disambiguation) Life and Living (disambiguation)Living''Life is a multi-faceted concept. ''Life'' may refer to an ongoing process of which living things are a part, the period between the conception (or a point at which the entity can be considered to be an individualized being) and death of an organism, the condition of an entity that has been born (or reached the point in its existence at which it can be established to be alive) and has yet to die, and that which makes a living thing alive.
Defining the concept of life - How can one tell when an entity is a lifeform? It would be relatively straightforward to offer a practical set of guidelines if one's only concern were life on Earth as we know it (see biosphere), but as soon as one considers questions about life's Origin of life (disambiguation)origins on Earth, or the possibility of extraterrestrial life, or the concept of artificial life, it becomes clear that the question is fundamentally difficult and comparable in many respects to the problem of defining intelligence (trait)intelligence. Also, loosely speaking, some theories are grounded in the basic assumption that Meme"ideas have a life of their own".
A conventional definition - unsolvedbiologyHow did life start? Is life a cosmic phenomenon? Are the conditions necessary for the origin of life narrow or broad? How did life originate and diversify in hundreds of millions of years? Why, after rapid diversification, do microorganisms remain unchanged for millions of years? Why have so many biological systems developed sexual reproduction? How do organisms recognize like species? How are the sizes of cells, organs, and bodies controlled? In biology, a lifeform has traditionally been considered to be a member of a population whose members can exhibit all the following phenomena at least once during their existence:#Growth, full development, maturity#MetabolismMetabolism, consuming, transforming and storing energy/mass; growing by absorbing and reorganizing mass; excreting waste#Motion, either moving itself, or having internal motion#ReproductionReproduction, the ability to create entities that are similar to, yet separate from, itself#Response to stimulusstimuli - the ability to measure properties of its surrounding natural environmentenvironment, and act upon certain conditions. This property is also called homeostasis.
Exceptions to the conventional definition - These criteria are not without their uses, but their disparate nature makes them unsatisfactory from a number of perspectives; in fact, it is not difficult to find counterexamples and examples that require further elaboration. For example, according to the above definition, one could say:Mules and people who are infertilityinfertile cannot reproduce and thus would not qualify as lifeforms. Also worker bees and other organisms living in colonies would not qualify; only the queen and the drones (or the whole colony) can be considered 'alive'.Fire and stars could be considered lifeforms.A virus (biology)virus does not grow and cannot reproduce outside of a host cell and thus would not qualify as a lifeform.Many individual organisms are incapable of reproduction and yet are still considered to be lifeforms; see mules and ants for examples. This is because the term "lifeform" applies on the level of entire species or of individual genes. (For example, see ''kin selection'' for information about one way by which non-reproducing individuals can still enhance the spread of their genes and the survival of their species.) It is important to keep in mind the difference between a "lifeform" and "a being that is alive." One example of sterilesterility does not render the rest of the species a non-lifeform, any more than one dead animal renders the rest of the species dead.Note also that the two cases of fire and stars fitting the definition of life can be simply remedied by defining metabolism in a more biochemically exact way. ''Fundamentals of Biochemistry'' by Donald Voet and Judith Voet (ISBN 0471586501) defines metabolism as follows: "Metabolism is the overall process through which living systems acquire and utilize the free energy they need to carry out their various functions. They do so by coupling the exergonic reactions of nutrient oxidation to the endergonic processes required to maintain the living state, such as the performance of mechanical work, the active transport of molecules against concentration gradients, and the biosynthesis of complex molecules." This definition, in use by most biochemists, makes it clear that fire is not alive, because fire releases all the oxidative energy of its fuel as heat.(Note: Actually, the definition does not help much at all. For it is circular. What we are looking for, after all, is a definition of "living entity." We agreed that part of the definition is "capable of metabolism." We then tried to define "metabolism" in order to get clear on which entities are capable of it and which not. But the definition of "metabolism" just offered is in terms of living systems. And those are exactly what we are trying to define!) This could also be remedied by adding the requirement of locality, where there is an obvious structure that delineates the spatial extension of the living being, such as a cell membrane. A conceptual problem with saying that fire is life is that it collapses the distinction between "growth" and "reproduction." It is possible to think of a spreading flame as either growing or reproducing, but what would it mean to say that the same act is ''both'' growth and reproduction? Viruses reproduce, flames grow, some software programs mutate and evolve, future software programs will probably evince (even high-order) behavior, machines move, and some form of proto-life consisting of metabolizing cells without the ability to reproduce presumably existed. Still, some would not call these entities alive. Generally, all five characteristics are required for a population to be considered a lifeform.
Other definitions - Biologists who are content to focus on terrestrial organisms often note some additional signs of life, including these:# Living organisms contain molecular components such as: carbohydrates, lipids, nucleic acids, and proteins.# Living organisms ''require'' both energy and matter in order to continue living.# Living organisms are composed of at least one cell (biology)cell.# Living organisms maintain homeostasis for some period of time. # Species of living organisms will evolutionevolve.All life on Earth is based on the chemistry of carbon compounds. Some assert that this must be the case for all possible forms of life throughout the universe; others describe this position as 'carbon chauvinism'.The Systems Theorysystemic definition is that living things are self-organizing and autopoiesisautopoietic (self-producing). These objects are not to be confused with Dissipative systemdissipative structures (e.g. fire). Variations of this definition include:Francisco Varela and Humberto Maturana's definition of life (also widely used by Lynn Margulis) as an autopoiesisautopoietic (self-producing), water based, lipid-protein bound, carbon metabolic, nucleic acid replicated, protein readout system"a system of inferior negative feedbacks subordinated to a superior positive feedback" (mol.uj.edu.pl - J. theor Biol. 2001)Tom Kinch's definition of life as a highly organized auto-cannibalizing system naturally emerging from conditions common on planetary bodies, and consisting of a population of replicators capable of mutation, around each set of which a homeostatic metabolizing organism, which actively helps reproduce and/or protect the replicator(s), has evolvedStuart Kauffman's definition of life as an agentautonomous agent or a multi-agent system capable of reproducing itself or themselves, and of completing at least one thermodynamic work cycleRobert Pirsig's definition of life, found in his book ''Lila: An Inquiry into Morals'', as that which maximizes its range of possible futures, in other words, that which makes decisions that result in the most future choices, or that which strives to keep its options open. A system converting entropy to negentropy, using flow of energy.Other definitions: That which seeks to continue its own existence (attributed to Clifford A. Schaffer).
Descent with modification: a "useful" characteristic - A useful characteristic upon which to base a definition of life is that of common descentdescent with modification: the ability of a life form to produce offspring that are like its parent or parents, but with the possibility of some variation due to chance. Descent with modification is sufficient by itself to allow evolution, assuming that the variations in the offspring allow for differential survival. The study of this form of heritability is called genetics. In all known life forms (assuming prions are not counted as such), the genetic material is primarily DNA or the related molecule, RNA. Another exception might be the software code of certain forms of computer virusviruses and programs created through genetic programming, but whether computer programs can be alive even by this definition is still a matter of some contention.
Origin of life - ''Main article Origin of lifeThere is no truly "standard" model of the origin of life, but most currently accepted models build in one way or another on the following discoveries, which are listed roughly in order of postulated emergence:#Plausible pre-biotic conditions result in the creation of the basic small molecules of life. This was demonstrated in the Miller experimentUrey-Miller experiment.#Phospholipids spontaneously form lipid bilayers, the basic structure of a cell membrane.#Procedures for producing random RNA molecules can produce ribozymes, which are able to produce more of themselves under very specific conditions.There are many different hypotheses regarding the path that might have been taken from simple organic molecules to protocells and metabolism. Many models fall into the "genes-first" category or the "metabolism-first" category, but a recent trend is the emergence of hybrid models that do not fit into either of these categories.
The possibility of extraterrestrial life - ''Main articles Extraterrestrial life, AstrobiologyAs of 2005, Earth is the only planet in the universe known by humans to support life. The question of whether life exists elsewhere in the universe remains open, but analyses such as the Drake equation have been used to estimate the probability of such life existing. There have been a number of claims of the discovery of life elsewhere in the universe, but none of these have yet survived scientific scrutiny.Today, the closest that scientists have come to finding extraterrestrial life is fossil evidence of possible bacteriumbacterial life on Mars (planet)Mars (via the ALH84001 meteorite). Searches for extraterrestrial life are currently focusing on planets and moons believed to possess liquid water, at present or in the past. Recent evidence from the NASA rovers MER-ASpirit and MER-BOpportunity supports the theory that Mars once had surface water. See ''Life on Mars'' for further discussion.Jupiter (planet)Jupiter's moons are also considered good candidates for extraterrestrial life, especially Europa (moon)Europa, which seems to possess oceans of liquid water.Other highly speculative and somewhat doubtful places for present or past life include the atmosphere of Venus, Titan (moon)Titan cyrovolcanoes, or even Enceladus (moon)Enceladus.
See also - Animal Artificial life Bacteria Biology Death Fungi Kingdom_%28biology%29Biological kingdom Biological life cycle Monera Odic force Origin of life (disambiguation) Plant Prehistoric life Protista
References - Kauffman, Stuart. The Adjacent Possible: A Talk with Stuart Kauffman. Retrieved Nov. 30, 2003 from edge.org
External links - define wikiquote edge.org - "The Adjacent Possible: A Talk with Stuart Kauffman"angelfire.com - Animals and other living things: their interests, mental capacities and moral entitlementstolweb.org - Tree of Life Web Project - Life on Earthplato.stanford.edu - Stanford Encyclopedia of Philosophy entryweb.archive.org - The Deep Hot Biosphere Theory (Thomas Gold)Category:Life Category:Biologyca:Vidada:Liv (biologi)de:Leben (Biologie)eo:Vivo !(biologio)es:Vidafi:Elämäfr: Viehe:חיי 501;hu:Életit:Vita? !(biologia)ja:生命k o:생명la:Vitams:Be nda? !hidupnl:Levenno:livpl:Życ iept:Vidaru:Жи
79;ньsimple:Lifesk :Životsl:Življenjesv :livuk:Жит&# 1090;яvi:Sự? !sốngzh:生命
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Websites
Subliminal Crusher
Subliminal Crusher Official Pages
http://www.subcrush.it
Natural Freedom
Natural Freedom has been produced to lead people into freedom, (a state of being in which we experience wellbeing, health and healing), to help this world to become a more loving, peaceful, trusting, friendlier, healthier world. Being simply, naturally nude releases us into freedom.
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US, Canadian and international online wills, power of attorney, living wills, funeral planning, online memorials and other advance directives.
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The first wishing well on planet...
Wishing well (well of wishing) is a term to describe special place where any wish would be sent and placed. It came from the idea that water contained deities or had been placed there as a gift from the gods, since water was a source of life and oftentimes a scarce commodity. Water was seen to have healing powers and therefore wells became popular with many people drinking, bathing or just simply wishing over it. We all believe that our guardian or dweller of this First Wishing Well only would receive and accept every wish on Earth. After uttering the wish, one would generally drop coins in the well. Coins would be placed there as gifts for the deity in thanks.
http://www.firstwishingwell.net
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Wyld Life
History, Changes and Education of One of the Few. Take a look at deployments and operations outside the United States. Learn what drives some of these individuals to the extreme in which they are. Enter if you are so bold.
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Get to know to your essence with the help of energy work. You make experiences which help you to find out how you are when you are who you are. In weekend seminars you explore how you can achieve more for yourself by participating in a group of people woh are joining their energies. How you get to an attitude towards life where you really take the responsability for your power, health, your place in society... Das PROJEKT is a place for people who want to live their life.
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Seamless Garment
A Web site promoting the seamless garment approach that life is a seamless garment from conception to natural death. This approach is inconsistent with war, abortion, the death penalty and euthanasia.
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Guided Bible Studies for Hungry Christians
Becker Bible Studies provide ministry to growing Christians all over the world, through the Guided Bible Studies for Hungry Christians series. These studies are popular among soldiers, youth, missionaries and prisoners, and are embraced by the King James Bible Adherents, Fundamental and Reform Movements to bring Christians back to the truth through God's Word.
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The Biking Life Magazine
A print and online publication that covers the motorcycle happenings in Missouri and Illinois, also lists biker friendly places, clubs and upcoming events.
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Creating a diet and exercise plan when your overweight and over 50
I'm over weight & over 50 and ready to create a new healthy lifestyle plan. This site is to help me create a fitness and diet plan that creates a healthy lifestyle.
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Alternative Thinking Institute Self Help Philosophy
An alternative thinking program that will bring more truth and create more love and happiness in your life.
http://www.rogerbondy.net/
USLegalWills.com – Online Legal Wills
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Cuban Comtemporary Photography
cubangallery.net is a on-line art space for some of the best cuban photographers; emerging and known artists. cubangallery.net is open to contemporary art and offers to his visitors high art quality and a wide outlook on contemporary photography. Contemporary cuban art is influenced by international trends but is still strongly enriched with the different cultures that live togheter in the isle.
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Farrell Backlund Insurance Agency
FBInsure.com provides online insurance quotes for residents of Massachusetts and Rhode Island. A service of the Farrell Backlund Insurance Agency in Taunton, Massachusetts. This site is a great resource for Massachusetts residents who are looking for competitive home, life, or auto insurance
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Athenslife
A site with all the news about entertainment and nightlife in Athens, television, cinema, art etc.
http://www.athenslife.gr/
BSA Troop 270 - Thurmont, MD
Boy Scouts of America Troop 270 of Thurmont Maryland 21788
http://www.troop270.com/
Photosub.eu - Open Underwater-Photography & Video - Online Gallery
Photosub.eu - is the free possibility for underwater photographers, divingclubs etc, to set ther UW-photos or pictorial material with dive related topics, online.
http://www.photosub.eu/
On-Line Gamers Anonymous
On-Line Gamers Anonymous is a fellowship of people sharing their experience, strengths and hope to help each other recover and heal from the problems caused by excessive, obsessive game playing.
http://www.olganon.org/
The 4 Realities of Success During and After College
A parent and student guide to achieving suceess in college, the senior year job search, the first professional job, and preparation for independent living. Topics include goals, study skills, relationships, resumes, succeeding in the workplace, more.
http://www.The4Realities.com
The Little Things
Positive thinking quotes, motivations and inspirations about the little things in life that keep us going and make us smile. Keep smiling. Be happy. Love yourself, love your family. Smile.
http://www.chench.com/thelittlethings/
AnalogHeart/Yoshinori Sakuma-sakuweb.com
Japanese modern arts by yoshinori sakuma from Tokyo
http://www.sakuweb.com/
http://www.leenakejriwal.com
Website of Kolkata based Indian creative / fine art photographer Leena Kejriwal.
http://www.leenakejriwal.com/
Conscious Living-Conscious Dying
The Institute for Living and Dying offers extensive insights and information on the spiritual dimensions of living and dying. seminars, audio program, trainings and meditations.
http://www.living-dying.com
Universe Evolution
A set of big waves is sufficient for explaining evolution of life and of the Universe
http://www.ontostat.com/
Tree of Life
Phylogenetic tree with information about the diversity of organisms on Earth, their history, and characteristics. An on-going multi-authored project hosted by the University of Arizona.
http://tolweb.org/
National Right to Life
Find information on partial-birth abortion, Congressional efforts, fetal development, euthanasia, and other human life issues.
http://www.nrlc.org/
Real Life
A daily online comic about the normal lives of some abnormal people. In otherwords, me and my friends.
http://www.reallifecomics.com
From WBEZ in Chicago - This American Life
Features many Sedaris bits in RealAudio.
http://www.thislife.org/
ZDNet: Reviews
Reviews of computers, hardware, internet accessories, software, gadgets. Prices are American.
http://reviews-zdnet.com.com/
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