Life generally refers to three American magazines:
The Life founded in 1883 was similar to Puck and published for 53 years as a general-interest light entertainment magazine, heavy on illustrations, jokes and social commentary. It featured some of the greatest writers, editors and cartoonists of its era, including Charles Dana Gibson, Norman Rockwell and Harry Oliver. During its later years, this magazine offered brief capsule reviews (similar to those in The New Yorker) of plays and movies currently running in New York City, but with the innovative touch of a colored typographic bullet appended to each review, resembling a traffic light: green for a positive review, red for a negative one, amber for mixed notices.
The Luce Life was the first all-photographic American news magazine, and it dominated the market for more than 40 years. The magazine sold more than 13.5 million copies a week at one point and was so popular that President Harry S. Truman, Sir Winston Churchill and General Douglas MacArthur all serialized their memoirs in its pages.
Perhaps one of the best-known pictures printed in the magazine was Alfred Eisenstaedt’s photograph of a nurse in a sailor’s arms, snapped on August 27, 1945, as they celebrated VJ Day in New York City. The magazine's place in the history of photojournalism is considered its most important contribution to publishing. Luce purchased the rights to the name from the publishers of the first Life but sold its subscription list and features to another magazine; there was no editorial continuity between the two publications.
Life was wildly successful for two generations before its prestige was diminished by economics and changing tastes. Since 1972, Life has twice ceased publication and resumed in a different form, before ceasing once again with the issue dated April 20, 2007. The brand name continues on the Internet and in occasional special issues.[2][1]
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Life was born January 4, 1883, in a New York City artist's studio at 1155 Broadway. The founding publisher was John Ames Mitchell, a 37-year old illustrator, who used a $10,000 inheritance to launch the weekly magazine. Mitchell created the first Life nameplate with cupids as mascots; he later drew its masthead of a knight leveling his lance at the posterior of a fleeing devil. Mitchell took advantage of a revolutionary new printing process using zinc-coated plates, which improved the reproduction of his illustrations and artwork. This edge helped because Life faced stiff competition from the bestselling humor magazines Judge and Puck, which were already established and successful. Edward Sandford Martin was brought on as Life’s first literary editor; the recent Harvard graduate was a founder of the Harvard Lampoon.
The motto of the first issue of Life was, “While there’s Life, there’s hope.” The new magazine set forth its principles and policies to its readers: “We wish to have some fun in this paper... We shall try to domesticate as much as possible of the casual cheerfulness that is drifting about in an unfriendly world... We shall have something to say about religion, about politics, fashion, society, literature, the stage, the stock exchange, and the police station, and we will speak out what is in our mind as fairly, as truthfully, and as decently as we know how.”[3]
The magazine was a success and soon attracted the industry’s leading contributors. Among the most important was Charles Dana Gibson. Three years after the magazine was founded, the Massachusetts native sold Life his first contribution for $4: a dog outside his kennel howling at the moon. Encouraged by a publisher who was also an artist, Gibson was joined in Life’s early days by such well-known illustrators as Palmer Cox (creator of the Brownie), A. B. Frost, Oliver Herford, and E. W. Kemble. Life attracted an impressive literary roster too: John Kendrick Bangs, James Whitcomb Riley, and Brander Matthews all wrote for the magazine at the turn of the century.
However, Life also had its dark side. Mitchell was sometimes accused of outright anti-Semitism. When the magazine blamed the theatrical team of Klaw & Erlanger for Chicago’s grisly Iroquois Theater Fire in 1903, a national uproar ensued. Life’s drama critic, the rascal James Stetson Metcalfe, was barred from the 47 Manhattan theatres controlled by the so-called Theatrical Syndicate. His magazine hit back with terrible cartoons of grotesque Jews with enormous noses.
Life became a place that discovered new talent; this was particularly true among illustrators. In 1908 Robert Ripley published his first cartoon in Life, 20 years before his Believe It or Not! fame. Norman Rockwell’s first cover for Life, "Tain’t You", was published May 10, 1917. Rockwell's paintings were featured on Life’s cover 28 times between 1917 and 1924. Rea Irvin, the first art director of The New Yorker and creator of Eustace Tilley, got his start drawing covers for Life.
Just as pictures would later become Life’s most compelling feature, Charles Dana Gibson dreamed up its most celebrated figure. His creation, the Gibson Girl, was a tall, regal beauty. After her early Life appearances in the 1890s, the Gibson Girl became the nation’s feminine ideal. The Gibson Girl was a publishing sensation and earned a place in fashion history.
This version of Life took sides in politics and international affairs, and published fiery pro-American editorials. Mitchell and Gibson were incensed when Germany attacked Belgium; in 1914 they undertook a campaign to push America into the war. Mitchell’s seven years spent at Paris art schools made him partial to the French; there wasn’t a shred of unbiased coverage of the war. Gibson drew the Kaiser as a bloody madman, insulting Uncle Sam, sneering at crippled soldiers, and even shooting Red Cross nurses. Mitchell lived just long enough to see Life’s crusade result in the U. S. declaration of war in 1917.
Following Mitchell’s death in 1918, Gibson bought the magazine for $1 million. But the world was a different place for Gibson’s publication. It was not the Gay Nineties where family-style humor prevailed and the chaste Gibson Girls wore floor-length dresses. World War I had spurred changing tastes among the magazine-reading public. Life’s brand of fun, clean, cultivated, humor began to pale before the new variety: crude, sexy, and cynical. Life struggled to compete on newsstands with such risqué rivals.
In 1920 Gibson tapped former Vanity Fair staffer Robert E. Sherwood to be editor. A World War I veteran and member of the Algonquin Round Table, Sherwood tried to inject sophisticated humor onto the pages. Life published Ivy League jokes, cartoons, flapper sayings and all-burlesque issues. Beginning in 1920 Life undertook a crusade against Prohibition. It also tapped the humorous writings of Frank Sullivan, Robert Benchley, Dorothy Parker, Franklin P. Adams and Corey Ford. Among the illustrators and cartoonists were Ralph Barton, Percy Crosby, Don Herold, Ellison Hoover, H. T. Webster, Art Young and John Held Jr.
Despite such all-star talents on staff, Life had passed its prime, and was sliding toward financial ruin. The New Yorker, debuting in February 1925, copied many of the features and styles of Life; it even raided its editorial and art departments. Another blow to Life’s circulation came from raunchy humor periodicals such as Ballyhoo and Hooey, which ran what can be termed outhouse gags. Esquire joined Life’s competitors in 1933. A little more than three years after purchasing Life, Gibson quit and turned the decaying property over to Publisher Clair Maxwell and Treasurer Henry Richter. Gibson retired to Maine to paint and lost active interest in the magazine, which he left deeply in the red.
Life had 250,000 readers in 1920. But as the Jazz Age rolled into the Great Depression, the magazine lost money and subscribers. By the time Maxwell and Editor George Eggleston took over, Life had switched from publishing weekly to monthly. The two men went to work revamping its editorial style to meet the times, and in the process it did win new readers. Life struggled to make a profit in the 1930s when Henry Luce pursued purchasing it.
Announcing the death of Life, Maxwell declared: “We cannot claim, like Mr. Gene Tunney, that we resigned our championship undefeated in our prime. But at least we hope to retire gracefully from a world still friendly.”
For Life’s final issue in its original format, 80 year-old Edward Sandford Martin was recalled from editorial retirement to compose its obituary. He wrote, “That Life should be passing into the hands of new owners and directors is of the liveliest interest to the sole survivor of the little group that saw it born in January 1883... As for me, I wish it all good fortune; grace, mercy and peace and usefulness to a distracted world that does not know which way to turn nor what will happen to it next. A wonderful time for a new voice to make a noise that needs to be heard!”[3]
In 1936 publisher Henry Luce paid $92,000 to the owners of Life magazine because he sought the name for Time Inc. Wanting only the old Life’s name in the sale, Time Inc. sold Life’s subscription list, features, and goodwill to Judge. Convinced that pictures could tell a story instead of just illustrating text, Luce launched Life on November 23, 1936. The third magazine published by Luce, after Time in 1923 and Fortune in 1930, Life gave birth to the photo magazine in the U.S., giving as much space and importance to pictures as to words. The first issue of Life, which sold for ten cents (approximately USD $1.48 in 2007, see Cost of Living Calculator) featured five pages of Alfred Eisenstaedt’s pictures.
When the first issue of Life magazine appeared on the newsstands, the U.S. was in the midst of the Great Depression and the world was headed toward war. Adolf Hitler was firmly in power in Germany. In Spain, General Francisco Franco’s rebel army was at the gates of Madrid; German Luftwaffe pilots and bomber crews, calling themselves the Condor Legion, were honing their skills as Franco’s air arm. Italy under Benito Mussolini annexed Ethiopia. Luce ignored tense world affairs when the new Life was unveiled: the first issue depicted the Fort Peck Dam in Montana photographed by Margaret Bourke-White.
The format of Life in 1936 was an instant classic: the text was condensed into captions for 50 pages of pictures. The magazine was printed on heavily coated paper that cost readers only a dime. The magazine’s circulation skyrocketed beyond the company’s predictions, going from 380,000 copies of the first issue to more than one million a week four months later.[4] It spawned many imitators, such as Look, which was founded just a year later in 1937, and folded in 1971.
Life got its own building at 19 West 31st Street, a Beaux-Arts architecture jewel built in 1894 and considered of "outstanding significance" by the New York Landmarks Preservation Commission. Later it moved editorial offices to 9 Rockefeller Plaza.
Luce pulled a stringer for Time, Edward K. Thompson, to become assistant picture editor in 1937. From 1949–1961 he was the managing editor and editor in chief, until his retirement in 1970. His influence was significant during the magazine’s heyday - roughly from 1936 until the mid-1960s. Thompson was known for the free rein he gave his editors, particularly a “trio of formidable and colorful women: Sally Kirkland, fashion editor; Mary Letherbee, movie editor; and Mary Hamman, modern living editor." [5]
The magazine became archly conservative, and attacked organized labor and trade unions. In August 1942, writing of labor unrest, Life concluded: "The morale situation is perhaps the worst in the U. S. …It is time for the rest of the country to sit up and take notice. For Detroit can either blow up Hitler or it can blow up the U. S." Detroit’s Mayor Edward J. Jeffries was outraged: "I'll match Detroit's patriotism against any other city's in the country. The whole story in Life is scurrilous. …I’d just call it a yellow magazine and let it go at that." [6] Martin R. Bradley, a U. S. Collector of Customs, was ordered to tear out of the August 17 issue five pages containing an article captioned "Detroit is Dynamite" before permitting copies of the magazine to cross the international border to Canada.
When the U. S. entered the war in 1941, so did Life. By 1944 not all of Time and Life's forty war correspondents were men; six were newswomen: Mary Welsh Hemingway, Margaret Bourke-White, Lael Tucker, Peggy Durdin, Shelley Smith Mydans, Annalee Jacoby, and Jacqueline Saix, an Englishwoman whose name is usually omitted (she and Welsh are the only women listed in Time's publisher's letter, May 8, 1944, as being part of the magazine's team) reported on the war for the company.
Life was pro-American and backed the war effort each week. In July 1942, Life launched its first art contest for soldiers and drew more than 1,500 entries, submitted by all ranks. Judges sorted out the best and awarded $1,000 in prizes. Life picked sixteen for reproduction in the magazine. Washington’s National Gallery agreed to put 117 on exhibition that summer.
The magazine employed the distinguished war photographer Robert Capa. A veteran of Collier's magazine, Capa was the sole photographer among the first wave of the D-Day invasion in Normandy, France, on June 6, 1944. A notorious controversy at the Life photography darkroom ensued after a mishap ruined dozens of Capa's photos that were taken during the beach landing; the magazine claimed in its captions that the photos were fuzzy because Capa's hands were shaking. He denied it; he later poked fun at Life by titling his memoir Slightly Out of Focus. In 1954, Capa was killed while working for the magazine while covering the First Indochina War after stepping on a landmine.
Each week during World War II the magazine brought the war home to Americans; it had photographers in all theaters of war, from the Pacific to Europe. The magazine was so iconic that it was imitated in enemy propaganda using contrasting images of Life and Death. [7]
In May 1950 the council of ministers in Cairo banned Life from Egypt, forever. All issues on sale were confiscated. No reason was given, but Egyptian officials expressed indignation over the April 10, 1950, story about King Farouk of Egypt, entitled the "Problem King of Egypt". The government considered it insulting to the country.
Life in the 1950s earned a measure of respect by commissioning work from top authors. After Life's publication in 1952 of Ernest Hemingway's The Old Man and the Sea, the magazine contracted with the author for a 4,000-word piece on bullfighting. Hemingway sent the editors a 10,000-word article, following his last visit to Spain in 1959 to cover a series of contests between two top matadors. The article was republished in 1985 as the novella The Dangerous Summer. [8]
In February 1953, just a few weeks after leaving office, President Harry S. Truman announced that Life magazine would handle all rights to his memoirs. Truman said it was his belief that by 1954 he would be able to speak more fully on subjects pertaining to the role his administration played in world affairs. Truman observed that Life editors had presented other memoirs with great dignity; he added that Life also made the best offer.
Dorothy Dandridge was the first African American woman to appear on the cover of the magazine in November 1954.
Life's motto became, "To see Life; see the world." In the post-war years it published some of the most memorable images of events in the United States and the world. It also produced many popular science serials such as The World We Live In and The Epic of Man in the early 1950s. The magazine continued to showcase the work of notable illustrators, including Alton S. Tobey, whose many contributions included the cover for a 1958 series of articles on the history of the Russian Revolution.
The magazine was losing readers as the 1950s drew to a close. In May 1959 it announced plans to reduce its regular newsstand price to 19 cents a copy from 25 cents. With the increase in television sales and viewership, interest in news magazines was waning. Life would need to reinvent itself.
In the 1960s the magazine was filled with color photos of movie stars, President John F. Kennedy and his family, the war in Vietnam, and the moon landing. Typical of the magazine’s editorial focus was a long 1964 feature on actress Elizabeth Taylor and her relationship to actor Richard Burton. Reporter Richard Meryman Jr. traveled with Taylor to New York, California, and Paris. Life ran a 6,000-word first-person article on the screen star. “I’m not a ‘sex queen’ or a ‘sex symbol,’ “ Taylor said. “I don’t think I want to be one. Sex symbol kind of suggests bathrooms in hotels or something. I do know I’m a movie star and I like being a woman, and I think sex is absolutely gorgeous. But as far as a sex goddess, I don’t worry myself that way... Richard is a very sexy man. He’s got that sort of jungle essence that one can sense... When we look at each other, it’s like our eyes have fingers and they grab ahold... I think I ended up being the scarlet woman because of my rather puritanical up bringing and beliefs. I couldn’t just have a romance. It had to be a marriage.”[9]
In the 1960s, the magazine’s photographs featured those by Gordon Parks. “The camera is my weapon against the things I dislike about the universe and how I show the beautiful things about the universe,” Parks recalled in 2000. “I didn’t care about Life magazine. I cared about the people,” he said.[10]
In March 1967 Life won the 1967 National Magazine Award, chosen by the Columbia University Graduate School of Journalism. The prestigious award paid tribute to the stunning photos coming out of the war in Southeast Asia, such as Henri Huet’s riveting series of a wounded medic that were published in January 1966. Increasingly, the photos that Life was printing of the war in Vietnam were searing images of death and loss.
However, despite the accolades the magazine continued to win, and publishing American’s mission to the moon in 1969, circulation was lagging. It was announced in January 1971 that Life would reduce its circulation from 8.5 million to 7 million in an effort to offset shrinking advertising revenues. Exactly one year later, Life cut its circulation from 7 million to 5.5 million beginning with the January 14, 1972, issue, publisher Gary Valk announced. Life was reportedly not losing money, but its costs were rising faster than its profits. Life lost credibility with many readers when it supported Clifford Irving, whose fraudulent autobiography of Howard Hughes was revealed as a hoax in January 1972. The magazine had purchased serialization rights to Irving's manuscript.
Industry figures showed that some 96 percent of Life's circulation went to mail subscribers, with only 4 percent coming from the more profitable newsstand sales. Valk was at the helm as publisher when hundreds lost their jobs. The end came when the weekly Life magazine shut down on December 8, 1972.
From 1972 to 1978, Time Inc. published ten Life Special Reports on such themes as “The Spirit of Israel”, “Remarkable American Women” and “The Year in Pictures”. With a minimum of promotion, those issues sold between 500,000 and 1 million copies at cover prices of up to $2.
In 1978, Life re-emerged as a monthly, and with this resurrection came a new, modified logo. Although still the familiar red rectangle with the white type, the new version was larger, and the lettering was closer together and the box surrounding it was smaller. (This "new" larger logo would be used on every issue until July 1993.)
Life continued for the next 22 years as a moderately successful general interest news features magazine. In 1986, it decided to mark its 50th anniversary under the Time Inc. umbrella with a special issue showing every Life cover starting from 1936, which of course included the issues that were published during the six-year hiatus in the 1970s. The circulation in this era hovered around the 1.5 million-circulation mark. The cover price in 1986 was $2.50. The publisher at the time was Charles Whittingham; the editor was Philip Kunhardt. Life also got to go back to war in 1991, and it did so just like in the 1940s. Four issues of this weekly Life in Time of War were published during the first Gulf War.
Hard times came to the magazine once again, and in February 1993 Life announced the magazine would be printed on smaller pages starting with its July issue. This issue would also mark the return of the original Life logo.
Also at this time, Life slashed advertising prices 35 percent in a bid to make the monthly publication more appealing to advertisers. The magazine reduced its circulation guarantee for advertisers by 12 percent in July 1993 to 1.5 million copies from the current 1.7 million. The publishers in this era were Nora McAniff and Edward McCarrick; Daniel Okrent was the editor. Life for the first time was the same trim size as its longtime Time Inc. sister publication, Fortune.
The magazine was back in the national consciousness upon the death in August 1995 of Alfred Eisenstaedt, the Life photographer whose pictures constitute some of the most enduring images of the 20th century. Eisenstaedt’s photographs of the famous and infamous — Adolf Hitler and Benito Mussolini, Marilyn Monroe, Ernest Hemingway, the Kennedys, Sophia Loren — won him worldwide renown and 87 Life covers.
In 1999 the magazine was suffering financially, but still made news by compiling lists to round out the 20th Century. Life editors ranked its 100 Most Important Events of the Millennium. This list has been criticized for being overly focused on Western achievements. The Chinese, for example, had invented type four centuries before Gutenberg, but with thousands of ideograms, found its use impractical. Life also published a list of the 100 Most Important People of the Millennium. This list, too, was criticized for focusing on the West. Also, Thomas Edison's number one ranking was challenged since there were others whose inventions (the combustion engine, the automobile, electricity-making machines, for example) had greater impact than Edison's. The top 100 most important people list was further criticized for mixing world-famous names, such as Isaac Newton, Albert Einstein, Louis Pasteur, and Leonardo da Vinci, with numerous Americans largely unknown outside of the United States (18 Americans compared to 13 Italians and French, 12 English).
It appeared that the money-losing magazine was just hanging on to make it into the 21st century, and it did, but barely. In March 2000, Time Inc. announced it would cease regular publication of Life with the May issue. “It’s a sad day for us here,” Don Logan, chairman and chief executive of Time Inc., told CNNfn.com. “It was still in the black,” he said, noting that Life was increasingly spending more to maintain its monthly circulation level of approximately 1.5 million. “Life was a general interest magazine and since its reincarnation, it had always struggled to find its identity, to find its position in the marketplace,” Logan said.[11]
For Life subscribers, remaining subscriptions were honored with other Time Inc. magazines, such as Time. And in January 2001, these subscribers received a special, Life-sized format of "The Year in Pictures" edition of Time magazine, which was in reality a Life issue disguised under a Time logo on the front. (Newsstand copies of this edition were actually published under the Life imprint.)
While citing poor advertising sales and a rough climate for selling magazine subscriptions, Time Inc. executives said a key reason for closing the title in 2000 was to divert resources to the company’s other magazine launches that year, such as Real Simple. Later that year, its parent company, Time Warner, struck a deal with the Tribune Company for Times Mirror magazines that included Golf, Ski, Skiing, Field & Stream, and Yachting. Life was not around when AOL and Time Warner announced their $183 billion merger, the largest corporate merger in history, which was finalized in January 2001.[12]
Life was absent from the U.S. market for only a few months, when it began publishing special newsstand "megazine" issues on topics such as 9/11 and the Holy Land in 2001. These issues, which were printed on thicker paper, were more like softcover books than magazines.
Beginning in October 2004, it was revived for a second time. Life resumed weekly publication as a free supplement to U.S. newspapers. Life went into competition for the first time with the two industry heavyweights, Parade and USA Weekend. At its launch, it was distributed with more than 60 newspapers with a combined circulation of approximately 12 million. Among the newspapers to carry Life: the Washington Post, New York Daily News, Los Angeles Times, Chicago Tribune, Denver Post, and St. Louis Post-Dispatch. Time Inc. made deals with several major newspaper publishers to carry the Life supplement, including Knight Ridder and the McClatchy Company.
This version of Life retained its trademark logo but sported a new cover motto, “America’s Weekend Magazine.” It measured 9½ x 11½ inches and was printed on glossy paper in full-color. On September 15, 2006, Life was just 20 pages. The editorial content contained one full-page photo, of actress Julia Louis-Dreyfus, and one three-page, seven-photo essay, of Kaiju Big Battel.
This era of Life lasted less than three years. On March 26, 2007, Time Inc. announced that it would fold the magazine as of April 20, 2007, although it would keep the web site.[2][1]
On November 18, 2008, Google began hosting an archive of the magazine's photographs, as part of a joint effort with Life.[13] Many images in this archive were never published in the magazine.[14] The archive is accessible through Google image search (see LIFE photo archive hosted by Google). Also, the full archive of the issues of the main run (1936-1972) is available through Google Book Search (see Google Books).
LIFE.com launched March 31, 2009. The site, a joint venture between Getty Images and Life magazine, offers millions of photographs from their combined collections. LIFE.com shares a partnership with Getty Images.[15]
Well-known contributors since 1936 have included:
| Life (Biota) |
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| File:Waitakere Piha Life on a rocky peak in the Waitakere Ranges
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| Scientific classification |
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| Domains and Kingdoms |
Life (cf. biota) is a characteristic that distinguishes objects that have self-sustaining biological processes ("alive," "living"), from those which do not[1][2] —either because such functions have ceased (death), or else because they lack such functions and are classified as "inanimate."
In biology, the science that studies living organisms, "life" is the condition which distinguishes active organisms from inorganic matter, including the capacity for growth, functional activity and the continual change preceding death.[3][4] A diverse array of living organisms (life forms) can be found in the biosphere on Earth, and properties common to these organisms—plants, animals, fungi, protists, archaea, and bacteria — are a carbon- and water-based cellular form with complex organization and heritable genetic information. Living organisms undergo metabolism, maintain homeostasis, possess a capacity to grow, respond to stimuli, reproduce and, through natural selection, adapt to their environment in successive generations. More complex living organisms can communicate through various means.[1][5]
In philosophy and religion, the conception and nature of life varies, and offer interpretations in the frameworks of existence and consciousness, and touch on many other related issues, such as, ontology, value, life stance, purpose, conceptions of God, the soul and the afterlife.
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It is still a challenge for scientists and philosophers to define life in unequivocal terms.[6][7][8] Any definition must be sufficiently broad to encompass all life with which we are familiar, and it should be sufficiently general that, with it, scientists would not miss life that may be fundamentally different from earthly life.[9]
In order to answer the question ‘What is life?’, some scientists have recently proposed that a general Living systems theory is required.[10] Such general theory, arising out of the biological sciences, attempts to map general principles for how all living systems work. Instead of examining phenomena by attempting to break things down into component parts, a general living systems theory explores phenomena in terms of dynamic patterns of relationship.[11]
Since there is no unequivocal definition of life, the consensus is to attempt to describe it. Therefore, life is a characteristic of organisms that exhibit all or most of the following phenomena:[12][13]
life]] |
plain]] |
of |
To reflect the minimum phenomena required, some have proposed other biological definitions of life:
Viruses are most often considered replicators rather than forms of life. They have been described as "organisms at the edge of life",[16] since they possess genes, evolve by natural selection,[17] and replicate by creating multiple copies of themselves through self-assembly. However, viruses do not metabolise and require a host cell to make new products. Virus self-assembly within host cells has implications for the study of the origin of life, as it may support the hypothesis that life could have started as self-assembling organic molecules.[18][19]
Biophysicists have also commented on the nature and qualities of life forms—notably that they function on negative entropy.[20][21] In more detail, according to physicists such as John Bernal, Erwin Schrödinger, Eugene Wigner, and John Avery, life is a member of the class of phenomena which are open or continuous systems able to decrease their internal entropy at the expense of substances or free energy taken in from the environment and subsequently rejected in a degraded form (see: entropy and life).[22][23]
Some of the earliest theories of life were materialist, holding that all that exists is matter, and that all life is merely a complex form or arrangement of matter. Empedocles (430 B.C.) argued that every thing in the universe is made up of a combination of four eternal 'elements' or 'roots of all': earth, water, air, and fire. All change is explained by the arrangement and rearrangement of these four elements. The various forms of life are caused by an appropriate mixture of elements. For example, growth in plants is explained by the natural downward movement of earth and the natural upward movement of fire.[24]
Democritus (460 B.C.), the disciple of Leucippus, thought that the essential characteristic of life is having a soul (psychê). In common with other ancient writers, he used the term to mean the principle of living things that causes them to function as a living thing. He thought the soul was composed of fire atoms, because of the apparent connection between life and heat, and because fire moves.[25] He also suggested that humans originally lived like animals, gradually developing communities to help one another, originating language, and developing crafts and agriculture.[26]
In the scientific revolution of the seventeenth century, mechanistic ideas were revived by philosophers like Descartes.
Hylomorphism is the theory (originating with Aristotle (322 BC)) that all things are a combination of matter and form. Aristotle was one of the first ancient writers to approach the subject of life in a scientific way. Biology was one of his main interests, and there is extensive biological material in his extant writings. According to him, all things in the material universe have both matter and form. The form of a living thing is its soul (Greek 'psyche', Latin 'anima'). There are three kinds of souls: the 'vegetative soul' of plants, which causes them to grow and decay and nourish themselves, but does not cause motion and sensation; the 'animal soul' which causes animals to move and feel; and the rational soul which is the source of consciousness and reasoning which (Aristotle believed) is found only in man.[27] Each higher soul has all the attributes of the lower one. Aristotle believed that while matter can exist without form, form cannot exist without matter, and therefore the soul cannot exist without the body.[28]
Consistent with this account is a teleological explanation of life. A teleological explanation accounts for phenomena in terms of their purpose or goal-directedness. Thus, the whiteness of the polar bear's coat is explained by its purpose of camouflage. The direction of causality is the other way round from materialistic science, which explains the consequence in terms of a prior cause. Most modern biologists now reject this functional view in terms of a material and causal one: biological features are to be explained not by looking forward to future optimal results, but by looking backwards to the past evolutionary history of a species, which led to the natural selection of the features in question.
Vitalism is the belief that the life-principle is essentially immaterial. This originated with Stahl, and held sway until the middle of the nineteenth century. It appealed to philosophers such as Henri Bergson, Nietzsche, Wilhelm Dilthey, anatomists like Bichat, and chemists like Liebig.
Vitalism underpinned the idea of a fundamental separation of 'organic' and inorganic material, and the belief that organic material can only be derived from living things. This was disproved in 1828 when Wöhler prepared urea from inorganic materials. This so-called Wöhler synthesis is considered the starting point of modern organic chemistry. It is of great historical significance because for the first time an organic compound was produced from inorganic reactants.
Later, Helmholtz, anticipated by Mayer, demonstrated that no energy is lost in muscle movement, suggesting that there were no vital forces necessary to move a muscle. These empirical results led to the abandonment of scientific interest in vitalistic theories, although the belief lingered on in non-scientific theories such as Homeopathy, which interprets diseases and sickness as caused by disturbances in a hypothetical vital force or life force.
For religious beliefs about the creation of life, see creation myth.
Although it has not been pinpointed exactly, evidence suggests that life on Earth has existed for about 3.7 billion years.[29] All known life forms share fundamental molecular mechanisms, and based on these observations, theories on the origin of life attempt to find a mechanism explaining the formation of a primordial single cell organism from which all life originates. There are many different hypotheses regarding the path that might have been taken from simple organic molecules via pre-cellular life 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.[30]
There is no scientific consensus as to how life originated and all proposed theories are highly speculative. However, most currently accepted scientific models build in one way or another on the following theories:
The diversity of life on Earth today is a result of the dynamic interplay between genetic opportunity, metabolic capability and environmental challenges.[32] For most of its existence, Earth's habitable environment has been dominated by microorganisms and subjected to their metabolism and evolution. As a consequence of such microbial activities on a geologic time scale, the physical-chemical environment on Earth has been changing, thereby determining the path of evolution of subsequent life.[32] For example, the release of molecular oxygen by cyanobacteria as a by-product of photosynthesis induced fundamental, global changes in the Earth's environment. The altered environment, in turn, posed novel evolutionary challenges to the organisms present, which ultimately resulted in the formation of our planet's major animal and plant species. Therefore this 'co-evolution' between organisms and their environment is apparently an inherent feature of living systems.[32]
The inert components of an ecosystem are the physical and chemical factors necessary for life – energy (sunlight or chemical energy), water, temperature, atmosphere, gravity, nutrients, and ultraviolet solar radiation protection.[33] In most ecosystems the conditions vary during the day and often shift from one season to the next. To live in most ecosystems, then, organisms must be able to survive a range of conditions, called 'range of tolerance'.[34] Outside of that are the 'zones of physiological stress', where the survival and reproduction are possible but not optimal. Outside of these zones are the 'zones of intolerance', where life for that organism is implausible. It has been determined that organisms that have a wide range of tolerance are more widely distributed than organisms with a narrow range of tolerance.[34]
Life has evolved strategies that allow it to survive even beyond the physical and chemical limits to which it has adapted to grow. To survive, some microorganisms can assume forms that enable them to withstand freezing, complete desiccation, starvation, high-levels of radiation exposure, and other physical or chemical challenges. Furthermore, they can survive exposure to such conditions for weeks, months, years, or even centuries.[32] Extremophiles are microbial life forms that thrive outside the ranges life is commonly found in. They also excel at exploiting uncommon sources of energy. While all organisms are composed of nearly identical molecules, evolution has enabled such microbes to cope with this wide range of physical and chemical conditions. Characterization of the structure and metabolic diversity of microbial communities in such extreme environments is ongoing. An understanding of the tenacity and versatility of life on Earth, as well as an understanding of the molecular systems that some organisms utilize to survive such extremes, will provide a critical foundation for the search for life beyond Earth.[32]
Traditionally, people have divided organisms into the classes of plants and animals, based mainly on their ability of movement. The first known attempt to classify organisms was conducted by the Greek philosopher Aristotle (384-322 BC). He classified all living organisms known at that time as either a plant or an animal. Aristotle distinguished animals with blood from animals without blood (or at least without red blood), which can be compared with the concepts of vertebrates and invertebrates respectively. He divided the blooded animals into five groups: viviparous quadrupeds (mammals), birds, oviparous quadrupeds (reptiles and amphibians), fishes and whales. The bloodless animals were also divided into five groups: cephalopods, crustaceans, insects (which also included the spiders, scorpions, and centipedes, in addition to what we now define as insects), shelled animals (such as most molluscs and echinoderms) and "zoophytes". Though Aristotle's work in zoology was not without errors, it was the grandest biological synthesis of the time and remained the ultimate authority for many centuries after his death.[1]
The exploration of the American continent revealed large numbers of new plants and animals that needed descriptions and classification. In the latter part of the 16th century and the beginning of the 17th, careful study of animals commenced and was gradually extended until it formed a sufficient body of knowledge to serve as an anatomical basis for classification.
In the late 1740s, Carolus Linnaeus introduced his method, still used, to formulate the scientific name of every species.[2] Linnaeus took every effort to improve the composition and reduce the length of the many-worded names by abolishing unnecessary rhetoric, introducing new descriptive terms and defining their meaning with an unprecedented precision. By consistently using his system, Linnaeus separated nomenclature from taxonomy. This convention for naming species is referred to as binomial nomenclature.
The fungi were originally treated as plants. For a short period Linnaeus had placed them in the taxon Vermes in Animalia. He later placed them back in Plantae. Copeland classified the Fungi in his Protoctista, thus partially avoiding the problem but acknowledged their special status.[3] The problem was eventually solved by Whittaker, when he gave them their own kingdom in his five-kingdom system. As it turned out, the fungi are more closely related to animals than to plants.[4]
As new discoveries enabled us to study cells and microorganisms, new groups of life were revealed, and the fields of cell biology and microbiology were created. These new organisms were originally described separately in protozoa as animals and protophyta/thallophyta as plants, but were united by Haeckel in his kingdom protista, later the group of prokaryotes were split off in the kingdom Monera, eventually this kingdom would be divided in two separate groups, the Bacteria and the Archaea, leading to the six-kingdom system and eventually to the current three-domain system.[5] The classification of eukaryotes is still controversial, with protist taxonomy especially problematic.[6]
As microbiology, molecular biology and virology developed, non-cellular reproducing agents were discovered, such as viruses and viroids. Sometimes these entities are considered to be alive but others argue that viruses are not living organisms since they lack characteristics such as cell membrane, metabolism and do not grow or respond to their environments. Viruses can however be classed into "species" based on their biology and genetics but many aspects of such a classification remain controversial.[7]
Since the 1960s a trend called cladistics has emerged, arranging taxa in an evolutionary or phylogenetic tree. It is unclear, should this be implemented, how the different codes will coexist.[8]
| Linnaeus 1735 2 kingdoms | Haeckel 1866[9] 3 kingdoms | Chatton 1937[10] 2 empires | Copeland 1956[11] 4 kingdoms | Whittaker 1969[12] 5 kingdoms | Woese et al. 1977[13] 6 kingdoms | Woese et al. 1990[5] 3 domains |
|---|---|---|---|---|---|---|
| (not treated) | Protista | Prokaryota | Monera | Monera | Eubacteria | Bacteria |
| Archaebacteria | Archaea | |||||
| Eukaryota | Protista | Protista | Protista | Eukarya | ||
| Vegetabilia | Plantae | Fungi | Fungi | |||
| Plantae | Plantae | Plantae | ||||
| Animalia | Animalia | Animalia | Animalia | Animalia |
Earth is the only planet in the universe known to harbour life. The Drake equation, which relates the number of extraterrestrial civilizations in our galaxy with which we might come in contact, has been used to discuss the probability of life elsewhere, but scientists disagree on many of the values of variables in this equation. Depending on those values, the equation may either suggest that life arises frequently or infrequently.
Panspermia and exogenesis are hypotheses proposing that life originated elsewhere in the universe and was subsequently transferred to Earth in the form of spores perhaps via meteorites, comets or cosmic dust. However, those hypotheses do not help explain the ultimate origin of life.
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Wikimedia Commons has media related to: Tree of life |
| Wikiquote has a collection of quotations related to: Life |
| Look up life or living in Wiktionary, the free dictionary. |
| Wikispecies has information related to: The Taxonomy of Life |
| Taxonomic ranks | ||||||||
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| Magnorder | ||||||||
| Domain/Superkingdom | Superphylum/Superdivision | Superclass | Superorder | Superfamily | Superspecies | |||
| Kingdom | Phylum/Division | Class | Legion | Order | Family | Tribe | Genus | Species |
| Subkingdom | Subphylum | Subclass | Cohort | Suborder | Subfamily | Subtribe | Subgenus | Subspecies |
| Infrakingdom/Branch | Infraphylum | Infraclass | Infraorder | Alliance | Infraspecies | |||
| Microphylum | Parvclass | Parvorder | ||||||
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Life is mainly a biological idea that has no simple definition. The study of life is called biology and people who study life are biologists. A lifespan is the average length of life in a species. All life is directly or indirectly powered by solar energy. Without energy from the sun no life could exist.
All known life on Earth is based on the chemistry of carbon compounds. Some say that this must be true for all possible forms of life throughout the Universe; others describe this position as "carbon chauvinism".
Currently, the Earth is the only planet in the Universe known to have things living on it. The question of whether life exists elsewhere in the Universe remains open. There have been a number of false alarms of life elsewhere in the Universe, but none of these apparent discoveries have so far been confirmed. The best evidence of life outside of Earth is fossil evidence of possible bacterial life on Mars.
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One explanation of life is called the cell theory. The cell theory has three basic points: All living things are made of cells. The cell is the smallest living thing that can do all the things needed for life. All cells must come from preexisting cells.
Something is often said to be alive if it:
However, there are a few exceptions to these rules. Because this definition is not exact, it could be said that:
Many organisms are not able to reproduce and yet are still generally considered to be "alive"; see mule and ant for examples. However, these exceptions can be covered by defining life at the level of entire species or of individual genes (for example, see kin selection for one way that non-reproducing individuals can still enhance the spread of their genes and the survival of their species).
The thermodynamic definition of life is any system which can keep its entropy levels below maximum (usually through adaptation and mutations).
Death is the end of life in a living system, or in a part of it.
Life insurances, including pensions and life annuities, provide payments depending on life or death of a particular person. Because of this, documents that may be required for payment are:
Port Ghalib march
Fish are examples of marine life |
Adult citrus root weevil, Diaprepes
An Adult citrus root weevil is an example of an insect |
Salmonella
Salmonella typhimurium is an example of bacteria |
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Chromista collage
Chromista is an example of protista (protozoa) |
Amanita muscaria
Amanita muscaria tyndrum (Fly agaric) is an example of fungi |
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   | "The Adjacent Possible: A Talk with Stuart Kauffman" - Edge: THE ADJACENT POSSIBLE |
| | Stanford Encyclopedia of Philosophy entry - Life (Stanford Encyclopedia of Philosophy) |
 | Life under extreme conditions - Larger Than Life Global Discussion Forums: You are using an invalid IP |
| | History of life through time - History of life through time |
| | Wikispecies - Wikispecies, free species directory |
| | Defining Life, Explaining Emergence - Defining Life, Explaining Emergence |
| | What is Life ? The Process from Birth to Death - What Is Life ? |
| | classifies - Human Knowledge: Foundations and Limits |
| | The Deep Hot Biosphere Theory (Thomas Gold) - The Deep, Hot Biosphere |
| | Life; birth to death, answers to some common questions - Life, from Birth to Death |
| | Animals and other living things: their interests, mental capacities and moral entitlements - Vincent Torley's Home Page |
| | Tree of Life Web Project - Life on Earth - Life on Earth |
| | Life's Rational Meaning - meaning of life from meaninginmylife.com |
| | Magazin Haberleri Güncel Magazin Hayatın En Güzel Anı Life Magazin - Magazin Haberleri, Magazin, Sosyete, Güzeller Galerisi, Frikik, BBG Evi, Ünlüler |
| | The Deep Hot Biosphere Theory (Thomas Gold) - CU People: Welcome |
| | Today life and stress - Elimina Stress, Ansia, Depressione, Attacchi di panico in 10 minuti al giorno! -- Benessere -- La nostra esclusiva tecnologia, migliora il tuo benessere, le tue performances mentali, ed elimina definitivamente lo stress, ansia e depressi |
| | Express your theory and meaning of life - Life Theory | Perception Speaks |
| | LIFE website - Coming to life |
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