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Encyclopedia > Gaia theory (science)

The Gaia hypothesis, a hypothesis put forward to explain a number of paradoxes about life and the earth was first formulated in the 1960s, by the independent research scientist James Lovelock. Until 1975 it was almost totally ignored. An article in the of February 15th, 1975 in the New Scientist and a popular book length version of the theory, published as "The Quest for Gaia" began to attract scientific and critical attention to the hypothesis. Championed by certain environmentalists and with some scientists, it was vociferously rejected by many others, both within and without science. [1]. James Lovelock in front of a statue of Gaia in 2000 Dr James Ephraim Lovelock CH CBE FRS, (born July 26, 1919) is an independent scientist, author, researcher and environmentalist who lives in Cornwall, in the south west of Great Britain. ... New Scientist cover - 18 December 2004 New Scientist is a weekly international science magazine covering recent developments in science and technology for a general English-speaking audience. ...


The Gaia hypothesis forms part of what is scientifically referred to as earth system science, is a class of scientific models of the geo-biosphere in which life as a whole fosters and maintains suitable conditions for itself by helping to create an environment on Earth suitable for its continuity. The first such theory was created by the atmospheric scientist and chemist , who was working with NASA when he developed his hypotheses in the 1960s. He wrote an article in the science journal Nature, before formally publishing the concept in the 1979 book Gaia: A new look at life on Earth. He hypothesized that the living matter of the planet functioned like a single organism and named this self-regulating living system after the Greek goddess Gaia, using a suggestion from the novelist William Golding. An abstract model (or conceptual model) is a theoretical construct that represents physical, biological or social processes, with a set of variables and a set of logical and quantitative relationships between them. ... The Geo-Biosphere refers to the tight coupling of biological with geological processes such as soil weathering, rates of erosion and deposition, as a result of the presence of the living tissues of the biosphere. ... Look up life, living in Wiktionary, the free dictionary. ... Earth (often referred to as The Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth in order of size. ... Meteorology is the scientific study of the atmosphere that focuses on weather processes and forecasting. ... Chemist Julie Perkins of Lawrence Livermore National Laboratory pours from a Florence flask. ... NASA logo Listen to this article · (info) This audio file was created from an article revision dated 2005-09-01, and does not reflect subsequent edits to the article. ... The outrageously crowded Woodstock festival epitomized the popular antiwar movement of the 60s. ... First title page, November 4, 1869 Nature is one of the oldest and most reputable scientific journals, first published on 4 November 1869. ... This page refers to the year 1979. ... In biology and ecology, an organism (in Greek organon = instrument) is a living complex adaptive system of organs that influence each other in such a way that they function as a more or less stable whole. ... // Greek mythology consists in part in a large collection of narratives that explain the origins of the world and detail the lives and adventures of a wide variety of gods, goddesses, heroes, and heroines. ... Gaia (pronounced //[citation needed], sometimes also // or //) (land or earth, from the Greek ; variant spelling Gaea—see also Ge from ) is a Greek goddess personifying the Earth. ... Sir William Gerald Golding (September 19, 1911 – June 19, 1993) was a British novelist, poet and winner of the Nobel Prize for Literature (1983), best known for his work Lord of the Flies. ...


Since 1971, the noted microbiologist Lynn Margulis has been Lovelock's most important collaborator in developing Gaian concepts (Turney 2003). 1971 (MCMLXXI) was a common year starting on Friday (the link is to a full 1971 calendar). ... A Microbiologist is a biologist that studies the field of microbiology. ... Lynn Margulis. ...


Gaia "theories" have non-technical predecessors in the ideas of several cultures. Today, "Gaia theory" is sometimes used among non-scientists to refer to hypotheses of a self-regulating Earth that are non-technical but take inspiration from scientific models. Among some scientists, "Gaia" carries connotations of lack of scientific rigor and quasi-mystical thinking about the planet Earth, and therefore Lovelock's hypothesis was received initially with much antagonism by much of the scientific community. No controversy exists, however, about the fact that life and the physical environment significantly influence one another (see Ecology). To meet Wikipedias quality standards, this article or section may require cleanup. ... Social Cognitive Perspective: Zimmerman et al specified three important characteristics: self-observation (monitoring ones activities); self-judgement (self-evaluation of ones performance) and self-reactions (reactions to performance outcomes) Cognitive Processing Perspective Winne & Marx posited that motivational thoughts and beliefs are governed by the basic principles of cognitive... Ernst Haeckel coined the term oekologie in 1866. ...

Contents


Range of views

The original Gaia hypothesis has split into a spectrum of hypotheses, ranging from the undeniable (Weak Gaia) to the radical (Strong Gaia).


At one end of this spectrum is the undeniable statement that the organisms on the Earth have radically altered its composition. A stronger position is that the Earth's biosphere effectively acts as if it is a self-organizing system, which works in such a way as to keep its systems in some kind of meta-equilibrium that is broadly conducive to life. The history of evolution, ecology and climate show that the exact characteristics of this equilibrium intermittently have undergone rapid changes, which are believed to have caused extinctions and felled civilisations (see climate change). Self-organization refers to a process in which the internal organization of a system, normally an open system, increases automatically without being guided or managed by an outside source. ... In epistemology, the prefix meta- is used to mean about (its own category). ... Look up equilibrium in Wiktionary, the free dictionary. ... In biology and ecology, extinction is the ceasing of existence of a species or group of taxa. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years Climate change refers to the variation in the Earths global climate or regional climates over time. ...


Biologists and earth scientists usually view the factors that stabilize the characteristics of a period as an undirected emergent property or entelechy of the system; as each individual species pursues its own self-interest, for example, their combined actions tend to have counterbalancing effects on environmental change. Opponents of this view sometimes point to examples of life's actions that have resulted in dramatic change rather than stable equilibrium, such as the conversion of the Earth's atmosphere from a reducing environment to an oxygen-rich one. However, proponents will point out that those atmospheric composition changes created an environment even more suitable to life. Emergence is the process of deriving some new and coherent structures, patterns and properties in a complex system. ... Entelechy is a philosophical concept of Aristotle. ... General Name, Symbol, Number oxygen, O, 8 Chemical series Nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless Atomic mass 15. ... Earths atmosphere is the layer of gases surrounding the planet Earth and retained by the Earths gravity. ...


Some go a step further and hypothesize that all lifeforms are part of one single living planetary being called Gaia. In this view, the atmosphere, the seas and the terrestrial crust would be results of interventions carried out by Gaia through the coevolving diversity of living organisms. While it is arguable that the Earth as a unit does not match the generally accepted biological criteria for life itself (Gaia has not yet reproduced, for instance; it still might spread to other planets through human space colonization and terraforming), many scientists would be comfortable characterising the earth as a single "system". Bumblebees and the flowers they pollinate co-evolve so that the flower is dependent on the bee and the bee is dependent on the flower for survival In Biology, Co-evolution is the mutual evolutionary influence between two species that become dependent on each other. ... Biology is the branch of science dealing with the study of life. ... Look up life, living in Wiktionary, the free dictionary. ... Artists conception of a space habitat called the Stanford torus, by Don Davis Space colonization, also called space settlement and space humanization, is the possible permanent autonomous (self-sufficient) human habitation of locations outside Earth. ... Artists conception of a terraformed Mars in three stages of development. ... Look up system in Wiktionary, the free dictionary. ...


The most extreme form of Gaia hypothesis is that the entire Earth is a single unified organism; in this view the Earth's biosphere is consciously manipulating the climate in order to make conditions more conducive to life. Scientists contend that there is no evidence at all to support this last point of view, and it has come about because many people do not understand the concept of homeostasis. Many non-scientists instinctively see homeostasis as an activity that requires conscious control, although this is not so. Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ...


Much more speculative versions of Gaia hypothesis, including all versions in which it is held that the Earth is actually conscious or part of some universe-wide evolution, are currently held to be outside the bounds of science. These are discussed in the Gaia philosophy article. Also outside the bounds of science is the Gaia Movement, a collection of different organisations operating in different countries, but all sharing a concern for how humans might live more sustainably within the "living system". To meet Wikipedias quality standards, this article or section may require cleanup. ... The Gaia Movement is an international network of individuals and Gaia groups, that share concerns with living more sustainably on the Earth. ...


Gaia Theories

Early modern parallels

In Lives of a Cell (1974), the biologist, Lewis Thomas, makes an observation very similar to Lovelock's Gaia hypothesis: Lewis Thomas (November 25, 1913 - December 3, 1993) was a physician, poet, etymologist, essayist, administrator, educator, policy advisor, and researcher. ...

I have been trying to think of the earth as a kind of organism, but it is no go. I cannot think of it this way. It is too big, too complex, with too many working parts lacking visible connections. The other night, driving through a hilly, wooded part of southern New England, I wondered about this. If not like an organism, what is it like, what is it most like? Then, satisfactorily for that moment, it came to me: it is most like a single cell.

Lovelock initial hypothesis

Lovelock defined Gaia as:

a complex entity involving the Earth's biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet.

His initial hypothesis was that the biomass modifies the conditions on the planet to make conditions on the planet more hospitable – the Gaia Hypothesis properly defined this "hospitality" as a full homeostasis. Lovelock's initial hypothesis, accused of being teleological by his critics, was that Gaia atmosphere is kept in homeostasis by and for the biosphere. The biosphere is the part of a planets outer shell — including air, land, surface rocks and water — within which life occurs, and which biotic processes in turn alter or transform. ... Saturns atmosphere is made up of hydorgen, helium and methane ... The worlds oceans as seen from the South Pacific Oceans (from Okeanos, Greek for river, the ancient Greeks noticed that a strong current flowed off Gibraltar, and assumed it was a great river) cover almost three quarters (71%) of the surface of the Earth, and nearly half of the... Soil is the material on the surface of a lithosphere subject to weathering, and especially the earthy portion of that material. ... Cybernetics is a theory of the communication and control of regulatory feedback. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Teleology (telos: end, purpose) is the philosophical study of design, purpose, directive principle, or finality in nature or human creations. ...


Lovelock suggested that life on Earth provides a cybernetic, homeostatic feedback system operated automatically and unconsciously by the biota, leading to broad stabilization of global temperature and chemical composition. Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Feedback is (generally) information about actions. ... Biota is the plant and animal life of a region or area. ...


With his initial hypothesis, Lovelock claimed the existence of a global control system of surface temperature, atmosphere composition and ocean salinity. His arguments were: The historical temperature record shows the fluctuations of the temperature of the atmosphere and the oceans throughout history, and in particular since 1850. ... Salinity is the saltiness or dissolved salt content of a body of water. ...

  • The global surface temperature of the Earth has remained constant, despite an increase in the energy provided by the Sun.
  • Atmospheric composition remains constant, even though it should be unstable.
  • Ocean salinity is constant.

Since life started on Earth, the energy provided by the Sun has increased by 25% to 30%; however the surface temperature of the planet has remained remarkably constant when measured on a global scale. Furthermore, he argued, the atmospheric composition of the Earth is constant. The Earth's atmosphere currently consists of 79% nitrogen, 20.7% oxygen and 0.03% carbon dioxide. Oxygen is the second most reactive element after fluorine, and should combine with gases and minerals of the Earth's atomosphere and crust. Traces of methane (at an amount of 100,000 tonnes produced per annum), should not exist, as methane is combustible in an oxygen atmosphere. This composition should be unstable, and its stability can only have been maintained with removal or production by living organisms. The Sun is the star at the center of our solar system. ...


Ocean salinity has been constant at about 3.4% for a very long time. Salinity stability is important as most cells require a rather constant salinity degree and do not tolerate much values above 5%. Ocean salinity constancy was a long-standing mystery, because river salts should have raised the ocean salinity much higher than observed. Recently it was suggested that salinity may also be strongly influenced by seawater circulation through hot basaltic rocks, and emerging as hot water vents on ocean spreading ridges. However, the composition of sea water is far from equilibrium, and it is difficult to explain this fact without the influence of organic processes.


The only significant natural source of atmospheric carbon dioxide (CO2) is volcanic activity, while the only significant removal is through the precipitation of carbonate rocks. In water, CO2 is dissolved as a "carbonic acid," which may be combined with dissolved calcium to form solid calcium carbonate (limestone). Both precipitation and solution are influenced by the bacteria and plant roots in soils, where they improve gaseous circulation, or in coral reefs, where calcium carbonate is deposited as a solid on the sea floor. Calcium carbonate can also be washed from continents to the sea where it is used by living organisms to manufacture carbonaceous tests and shells. Once dead, the living organisms' shells fall to the bottom of the oceans where they generate deposits of chalk and limestone. Part of the organisms with carboneous shells are the coccolithophores (algae), which also happen to participate in the formation of clouds. When they die, they release a sulfurous gas (DMS), (CH3)2S, which act as particles on which water vapor condenses to make clouds. Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ... Coccolithophores are single-celled algae belonging to the haptophytes. ... A seaweed (Laurencia) up close: the branches are multicellular and only about 1 mm thick. ... Condensation is the change in matter1 of a substance to a denser phase, such as a puppy gas (or vapor) to a liquid. ...


Lovelock sees this as one of the complex processes that maintain conditions suitable for life. The volcanoes produce CO2 in the atmosphere, CO2 participates in rock weathering as carbonic acid, itself accelerated by temperature and soil life, the dissolved CO2 is then used by the algae and released on the ocean floor. CO2 excess can be compensated by an increase of coccolithophoride life, increasing the amount of CO2 locked in the ocean floor. Coccolithophorides increase the cloud cover, hence control the surface temperature, help cool the whole planet and favor precipitations which are necessary for terrestrial plants. For Lovelock, coccolithophorides are one stage in a regulatory feedback loop. Lately the atmospheric CO2 concentration has increased and there is some evidence that concentrations of ocean algal blooms are also increasing. In cybernetics and control theory, feedback is a process whereby some proportion or in general, function, of the output signal of a system is passed (fed back) to the input. ... An algal bloom is a relatively rapid increase in the population of (usually) phytoplankton algae in an aquatic system. ...


Critical analysis

Basis

This theory is based on the simple idea that the biomass self-regulates the conditions on the planet to make its physical environment (in particular temperature and chemistry of the atmosphere) on the planet more hospitable to the species which constitute its "life". The Gaia Hypothesis proper defined this "hospitality" as a full homeostasis. A simple model that is often used to illustrate the original Gaia Hypothesis is the so-called Daisyworld simulation. To meet Wikipedias quality standards, this article or section may require cleanup. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Daisyworld, a computer simulation, is a hypothetical world orbiting a sun whose temperature is slowly increasing in the simulation. ...


Whether this sort of system is present on Earth is still open to debate. Some relatively simple homeostatic mechanisms are generally accepted. For example, when atmospheric carbon dioxide levels rise, plants are able to grow better and thus remove more carbon dioxide from the atmosphere, but the extent to which these mechanisms stabilize and modify the Earth's overall climate are not yet known. Less clear is the reason why such traits evolve in a system in order to produce such effects. Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Layers of Atmosphere (NOAA) Air redirects here. ... Carbon dioxide is an atmospheric gas comprised of one carbon and two oxygen atoms. ...


Criticism

After initially being largely ignored by scientists, (from 1969 till 1977), thereafter for a period, the initial Gaia hypothesis was ridiculed by some scientists. On the basis of its name alone, the Gaia hypothesis was derided as some kind of neo-Pagan New Age religion. Many scientists in particular also criticised the approach taken in his popular book "Gaia, a New look at Life on Earth" for being teleological; a belief that all things have a predetermined purpose. Lovelock seems to have accepted this criticism of some of his statements, and has worked hard to remove the taint of teleological purpose from his theories, stating "Nowhere in our writings do we express the idea that planetary self-regulation is purposeful, or involves foresight or planning by the biota." – (Lovelock, J. E. 1990). Neopaganism (sometimes Neo-Paganism, meaning New Paganism) is a heterogeneous group of religions which attempt to revive ancient, mainly European pre-Christian religions. ... New Age describes a broad movement characterized by alternative approaches to traditional Western culture. ... Teleology (telos: end, purpose) is the philosophical study of design, purpose, directive principle, or finality in nature or human creations. ... Biota is the plant and animal life of a region or area. ...


In 1981, W. Ford Doolittle, in the CoEvolution Quarterly article "Is Nature Motherly" argued that there was nothing in the genome of individual organisms which could provide the feedback mechanisms Gaia theory proposed, and that therefore the Gaia hypothesis was an unscientific theory of a maternal type without any explanatory mechanism. In 1982 Richard Dawkins in his book The Blind Watchmaker argued that organisms could not act in concert as this would require foresight and planning from them. Like Doolittle he rejected the possibility that feedback loops could stabilize the system. Dawkins claimed "there was no way for evolution by natural selection to lead to altruism on a Global scale". W. Ford Doolittle Dr. W. Ford Doolittle (born 1942 in Urbana, Illinois) is a biochemist. ... CoEvolution Quarterly (later re-named Whole Earth Review) was one of the publishing ventures of the same visionary biologist (with interests in cultures and in art) who launched the Whole Earth Catalog and an early Internet community, still functioning, called the WELL. Stewart Brand is the name of this editor... In biology the genome of an organism is the whole hereditary information of an organism that is encoded in the DNA (or, for some viruses, RNA). ... Richard Dawkins Clinton Richard Dawkins DSc, FRS, FRSL (known as Richard Dawkins; born March 26, 1941) is an eminent British ethologist, evolutionary theorist, and popular science writer who holds the Charles Simonyi Chair in the Public Understanding of Science at Oxford University. ... Cover illustration by the zoologist Desmond Morris The Blind Watchmaker is a 1986 book by Richard Dawkins in which he presents an explanation of, and argument for, the theory of evolution by means of natural selection. ... Altruism is the practice of placing others before oneself. ...


At the American Geophysical Union's first Chapman Conference on Gaia, held at San Diego in 1981, James Kirchner criticised the Gaia hypothesis for its imprecision. He claimed that Lovelock and Margulis had not presented one Gaia hypothesis, but four - The American Geophysical Union (or AGU) is a nonprofit organization of geophysicists, consisting (as of 2004) of over 41,000 members from 130 countries. ... James Kirchner is professor of Earth and Planetary Science at University of California, Berkeley. ...

  • CoEvolutionary Gaia - that life and the environment had evolved in a coupled way. Kirchner claimed that this was already accepted scientifically and was not new.
  • Homeostatic Gaia - that life maintained the stability of the natural environment, and that this stability enabled life to continue to exist.
  • Geophysical Gaia - that the Gaia theory generated interest in geophysical cycles and therefore led to interesting new research in terrestrial geophysical dynamics.
  • Optimising Gaia - that Gaia shaped the planet in a way that made it an optimal environment for life as a whole. Kirchner claimed that this was not testable and therefore was not scientific.

Of Homeostatic Gaia, Kirchner recognised two alternatives. "Weak Gaia" asserted that life tends to make the environment stable for the flourishing of all life. "Strong Gaia" according to Kirchner, asserted that life tends to make the envronment stable, in order to enable the flourishing of all life. Strong Gaia, Kirchner claimed, was untestable and therefore not scientific. Bumblebees and the flowers they pollinate co-evolve so that the flower is dependent on the bee and the bee is dependent on the flower for survival In Biology, Co-evolution is the mutual evolutionary influence between two species that become dependent on each other. ... Homeostasis or homoeostasis is the property of an open system, especially living organisms, to regulate its internal environment so as to maintain a stable condition, by means of multiple dynamic equilibrium adjustments controlled by interrelated regulation mechanisms. ... ‹ The template below has been proposed for deletion. ...


Lawrence Joseph in his book "Gaia: the birth of an idea" demonstrated that Kirchner's attack was principally against Lovelock's integrity as a scientist, and was graciously ignored at the gathering by Lovelock himself. Nevertheless he and other Gaia inspired scientists have worked hard to disprove the claim that the theory is not scientific because it is impossible to test it by controlled experiment. Against the charge that Gaia was Teleological Lovelock and Andrew Watson offered the Daisyworld model as mathematical evidence to refute most of these criticisms. Daisyworld, a computer simulation, is a hypothetical world orbiting a sun whose temperature is slowly increasing in the simulation. ...


A final criticism leveled against the idea that Gaia is a "living" organism is the fact that the planet has not and is unable to reproduce. Certainly one of the hallmarks of living organisms is their ability to replicate and pass on their genetic information to succeeding generations. But the same criticism could be levelled at a sterile mule, or of a seventy year old spinster. We have no difficulty recognising the fact that they are alive even though they cannot reproduce. Other Gaians have proposed that Gaia is still too young to reproduce and this is not to say that it is conceptually impossible, as humankind may be the means by which Gaia will reproduce. Humanity's exploration of space, its interest in colonizing other planets, and the large body of sci-fi literature that describes terraforming, lend strong evidence to the idea that Gaia is planning to reproduce. The astronomer Carl Sagan also remarked that from a cosmic viewpoint, the space probes since 1959 have the character of a planet preparing to go to seed. It has been suggested that Minimum deterrence be merged into this article or section. ...


DaisyWorld simulations

Lovelock responded to criticisms with the mathematical Daisyworld model (1983), first to prove the existence of feedback mechanisms, second to demonstrate it was possible that control of the global biomass could occur without consciousness being involved. Daisyworld, a computer simulation, is a hypothetical world orbiting a sun whose temperature is slowly increasing in the simulation. ...


More recently, studies of artificial life using various guilds, of photosynthesisers, herbivores, carnivores, scavengers and decomposers, enables nutrient recycling within a regulatory framework derived by natural selection amongst species, where one being's harmful waste, becomes low energy food for members of another guild. This research on the Redfield Ratio of Nitrogen to Phosphorus, shows that local biotic processes can regulate global systems (See Keith Downing & Peter Zvirinsky, The Stimulated Evolution of Biochemical Guilds: Reconciling Gaia Theory with Natural Selection). Artificial life, also known as alife or a-life, is the study of life through the use of human-made analogs of living systems. ... The leaf is the primary site of photosynthesis in plants. ... A deer and two fawns feeding on some foliage In zoology, an herbivore is an animal that is adapted to eat primarily plant matter (rather than meat). ... The lion is a well-known, truly carnivorous member of the order Carnivora. ... Harvestman eating the tail of a five-lined skink The word scavenger, in zoology, refers to animals that consume already dead organic life-forms. ... Rotting fruit Decomposition is a phenomenon common in the sciences of biology and chemistry. ...   The Recycling symbol. ... Natural selection is the process by which individual organisms with favorable traits are more likely to survive and reproduce. ... In biology, a species is one of the basic units of biodiversity. ...


The First Gaia Conference

In 1988, to draw attention to the Gaia hypothesis, the climatologist Stephen Schneider organised a conference of the American Geophysical Union solely to discuss Gaia. The accusations of teleologism were largely dropped after that meeting. Climatology is the study of climate, and is a branch of the atmospheric sciences. ... Stephen H. Schneider (born ca. ... The American Geophysical Union (or AGU) is a nonprofit organization of geophysicists, consisting (as of 2004) of over 41,000 members from 130 countries. ... Teleology (telos: end, purpose) is the philosophical study of design, purpose, directive principle, or finality in nature or human creations. ...


Lovelock was careful to present a version of the Gaia Hypothesis which had no claim that Gaia intentionally or consciously maintained the complex balance in her environment that life needed to survive. It would appear that the claim that Gaia acts "intentionally" was a metaphoric statement in his popular initial book and was not meant to be taken literally. This new statement of the Gaia hypothesis was more acceptable to the scientific community. He supported this hypothesis with the example of Daisyworld. Using computer simulations of a hypothetical Daisyworld (with no atmosphere, taking into account only the different albedos of a black and white daisy type) and a mathematical approach, Lovelock and Andrew Watson proved that the controlled stability of the climate was an automatic consequence of the feedback mechanisms that would foster one kind of daisy over another. Thus the Gaian stabilities were not being teleological. The Gaia hypothesis had always asserted that Gaia was homeostatic, i.e. that the biota influence the abiotic world in a way that involves homeostatic feedback. Later tests, using grey daisies in addition to black and white ones, from which mutations could lead to evolution of different colours, and the introduction of daisy eating rabbits and rabbit eating foxes only seemed to increase the stability of the Daisyword simulations. Kirchner responded that these results were predicatble because of the intention of the programmers - Lovelock and Watson, who selected examples which would produce the responses they desired. More recently other research since the first conference, modelling the real biochemical cycles of Earth, and using various "guilds" of life (eg. photosynthesisers, decomposers, herbivores and primary and secondary carnivores has also been shown to produce Daisyworld-like regulation and stability, which helps to explain planetary biological diversity. Daisyworld, a computer simulation, is a hypothetical world orbiting a sun whose temperature is slowly increasing in the simulation. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Abiotic factors are the non-living factors of the Earth which affect the ability of living organisms to survive in an environment. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... The leaf is the primary site of photosynthesis in plants. ... Rotting fruit Decomposition is a phenomenon common in the sciences of biology and chemistry. ... In zoology, an herbivore is an animal that is adapted to eat primarily plants (rather than meat). ... This article deals with meat-eating animals. ... Rainforests are the most biodiverse ecosystems on earth Biodiversity or biological diversity is the diversity of life. ...


Strong and weak Gaia hypotheses

Despite the evidence that Gaia Theory has developed considerably[2] many critics have still not progressed beyond Kirchner's original attacks on Gaia Theory. They persist in stating that several types of strong Gaia hypotheses may be defined. A version called "Optimizing Gaia" asserts that biota manipulate their physical environment for the purpose of creating biologically favorable, or even optimal, conditions for themselves. "The Earth's atmosphere is more than merely anomalous; it appears to be a contrivance specifically constituted for a set of purposes" (Lovelock and Margulis, 1974). Further, "...it is unlikely that chance alone accounts for the fact that temperature, pH and the presence of compounds of nutrient elements have been, for immense periods, just those optimal for surface life. Rather, ... energy is expended by the biota to actively maintain these optima."


Another strong hypothesis is the one called "Omega Gaia". Teilhard de Chardin claimed that the Earth is evolving through stages of cosmogenesis, affecting the geosphere, biogenesis of the biosphere, and noogenesis of the noosphere, culminating in the Omega Point. This article needs cleanup. ... Cosmogenesis is the term created by the French Jesuit Priest and Scientist Pierre Teilhard de Chardin to describe the cosmological process of the creation of the Universe. ... Geosphere is a term denoting the solid body of the Earth (i. ... Biogenesis has two meanings. ... The biosphere is the part of a planets outer shell — including air, land, surface rocks and water — within which life occurs, and which biotic processes in turn alter or transform. ... This article needs to be cleaned up to conform to a higher standard of quality. ... The noosphere can be seen as the sphere of human thought being derived from the Greek νους (nous) meaning mind in the style of atmosphere and biosphere. Just as the biosphere is composed of all the organisms on Earth and their interactions, the noosphere is composed of all the interacting minds... Omega point is a term invented by Pierre Teilhard de Chardin to describe the ultimate maximum level of complexity-consciousness, considered by him the aim towards which consciousness evolves. ...


Weak Gaian hypotheses suggest that Gaia is co-evolutive. Co-evolution in this context has been thus defined: "Biota influence their abiotic environment, and that environment in turn influences the biota by Darwinian process." Lovelock (1995) gave evidence of this in his second book, showing the evolution from the world of the early thermo-acido-phyllic and methanogenic bacteria towards the oxygen enriched atmosphere today that supports more complex life. Bumblebees and the flowers they pollinate have co-evolved so that both have become dependent on each other for survival. ... Biota is the plant and animal life of a region or area. ... Biota is the plant and animal life of a region or area. ... Charles Darwin Darwinism is a term for the underlying theory in those ideas of Charles Darwin concerning evolution and natural selection. ... Subgroups Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular: bacterium) are a major group of living organisms. ... Methanogens are Archaea that produce methane as a metabolic by-product. ... The Phanerozoic (occasionally Phaenerozoic) Eon is the period of geologic time during which abundant animal life has existed. ...


The weakest form of the theory has been called "influential Gaia". It states that biota barely influence certain aspects of the abiotic world, e.g. temperature and atmosphere. Few would disagree. Biota is the plant and animal life of a region or area. ... Abiotic factors are the non-living factors of the Earth which affect the ability of living organisms to survive in an environment. ...


The weak versions are more acceptable from an orthodox science perspective, as they assume non-homeostasis. They state the evolution of life and its environment may affect each other. An example is how the activity of photosynthetic bacteria during Precambrian times have completely modified the Earth atmosphere to turn it aerobic, and as such supporting evolution of life (in particular eukaryotic life) . However, these theories do not claim the atmosphere modification has been done in coordination and through homeostasis. Also such critical theories have yet to explain how conditions on Earth have not been changed by the kinds of run-away positive feedbacks that have effected Mars and Venus. Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... The leaf is the primary site of photosynthesis in plants. ... Layers of Atmosphere (NOAA) Air redirects here. ... This is the current Astronomy collaboration of the week! Please help improve it to featured article standard. ... Adjective Venusian or (rarely) Cytherean (*min temperature refers to cloud tops only) Atmospheric characteristics Atmospheric pressure 9. ...


Unfortunately, some critics argue, many supporters of the various Gaia theories do not state exactly where they sit on this spectrum; this makes discussion and criticism difficult. More recently, after other conferences, the whole spectrum of "weak" and "strong Gaia" itself has been called into question. The "Gaia Hypothesis" has developed into "Gaia Theory" and even "Gaia Science" where a variety of different interpretations and modifications are simultaneously developing. Much effort on behalf of those analyzing the theory currently is an attempt to clarify what these different hypotheses are, and devising and presenting variours proposals that "test" the various outcomes.


Controversial concepts

Lovelock, especially in his older texts, has often indulged in language that has later caused fiery debates. What does he mean in the first paragraph of his first Gaia book (1979), when he writes that "the quest for Gaia is an attempt to find the largest living creature on Earth"? How "alive" is that, and in what respect? Is Gaia really an organism? In what sense? And in what sense does the cybernetic system called Gaia seek "an optimal physical and chemical environment for life on this planet"? Optimal for whom?


Lynn Margulis, the coauthor of Gaia hypotheses, is more careful to avoid controversial figures of speech than is Lovelock. In 1979 she wrote, in particular, that only homeorhetic and not homeostatic balances are involved: that is, the composition of Earth's atmosphere, hydrosphere, and lithosphere are regulated around "set points" as in homeostasis, but those set points change with time. Also she wrote that there is no special tendency of biospheres to preserve their current inhabitants, and certainly not to make them comfortable. Accordingly, the Earth is not a living organism which can live or die all at once, but rather a kind of community of trust which can exist at many discrete levels of integration. But this is true of all multicellular organisms, not all cells in the body die instantaneously. Homeorhesis, derived from the Greek for similar flow, is a concept encompassing dynamical systems which return to a trajectory, as opposed to systems which return to a particular state, which is termed homeostasis. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Homeostasis is the property of an open system, especially living organisms, to regulate its internal environment to maintain a stable, constant condition, by means of multiple dynamic equilibrium adjustments, controlled by interrelated regulation mechanisms. ... Earth (often referred to as The Earth) is the third planet in the solar system in terms of distance from the Sun, and the fifth in order of size. ... Multicellular organisms are those organisms containing more than one cell, and having differentiated cells that perform specialized functions. ...


In her 1998 book, The Symbiotic Planet, Margulis dedicated the last of the book's eight chapters to Gaia. She resented the widespread personification of Gaia and stressed that Gaia is "not an organism", but "an emergent property of interaction among organisms". She defined Gaia "the series of interacting ecosystems that compose a single huge ecosystem at the Earth's surface. Period." Yet still she argues, "the surface of the planet behaves as a physiological system in certain limited ways". Margulis seems to agree with Lovelock in that, in what comes to these physiological processes, the earth's surface is "best regarded as alive". The book's most memorable "slogan" was actually quipped by a student of Margulis': "Gaia is just symbiosis as seen from space". This neatly connects Gaia theory to Margulis' own theory of endosymbiosis.


Both Lovelock's and Margulis's understanding of Gaia are now largely considered valid scientific hypotheses, though controversies continue.


Recent developments

The Second Gaia Conference

By the time of the 2nd Chapman Conference on the Gaia Hypothesis, held at Valencia, in Spain on the 23 June 2000, the situation had developed significantly in accordance with the developing science of Bio-geophysiology. Rather than a discussion of the Gaian teleological views, or "types" of Gaia Theory, the focus was upon the specific mechanisms by which basic short term homeostasis was maintained within a framework of significant evolutionary long term structural change.


The major questions were:--


A. "How has the global biogeochemical/climate system called Gaia changed in time? What is its history? Can Gaia maintain stability of the system at one time scale but still undergo vectorial change at longer time scales? How can the geologic record be used to examine these questions?


B. What is the structure of Gaia? Are the feedbacks sufficiently strong to influence the evolution of climate? Are there parts of the system determined pragmatically by whatever disciplinary study is being undertaken at any given time or are there a set of parts that should be taken as most true for understanding Gaia as containing evolving organisms over time? What are the feedbacks among these different parts of the Gaian system, and what does the near closure of matter mean for the structure of Gaia as a global ecosystem and for the productivity of life?


C. How do models of Gaian processes and phenomena relate to reality and how do they help address and understand Gaia? How do results from Daisyworld transfer to the real world? What are the main candidates for "daisies"? Does it matter for Gaia theory whether we find daisies or not? How should we be searching for daisies, and should we intensify the search? How can Gaian mechanisms be investigated using process models or global models of the climate system which include the biota and allow for chemical cycling?"


Tyler Volk (1997) has suggested that once life evolves, a Gaian system is almost inevitably produced as a result of an evolution towards far-from-equilibrium homeostatic states that maximise entropy production (MEP). Kleidon (2004) agrees with Volk's hypothesis, stating: "...homeostatic behavior can emerge from a state of MEP associated with the planetary albedo"; "...the resulting behavior of a biotic Earth at a state of MEP may well lead to near-homeostatic behavior of the Earth system on long time scales, as stated by the Gaia hypothesis." Staley (2002) has similarly proposed "...an alternative form of Gaia theory based on more traditional Darwinian principles... In [this] new approach, environmental regulation is a consequence of population dynamics, not Darwinian selection. The role of selection is to favor organisms that are best adapted to prevailing environmental conditions. However, the environment is not a static backdrop for evolution, but is heavily influenced by the presence of living organisms. The resulting co-evolving dynamical process eventually leads to the convergence of equilibrium and optimal conditions."


Global warming inevitable

In Lovelock's latest book, The Revenge of Gaia, he argues that because of global warming the world population should brace itself for the inevitable: most of the planet will become uninhabitable by the end of this century (Anon., 2006).


Gaia hypothesis in ecology

After much initial criticism, a modified Gaia hypothesis is now considered within ecological science basically consistent with the planet earth being the ultimate object of ecological study. Ecologists generally consider the biosphere as an ecosystem and the Gaia hypothesis, though a simplification of that original proposed, to be consistent with a modern vision of global ecology, relaying the concepts of biosphere and biodiversity. The Gaia hypothesis has been called geophysiology or Earth system science, which takes into account the interactions between biota, the oceans, the geosphere, and the atmosphere. Ernst Haeckel coined the term oekologie in 1866. ... In ecology, an ecosystem is a combination of all the living and non-living elements of an area. ... The biosphere is the part of a planets outer shell — including air, land, surface rocks and water — within which life occurs, and which biotic processes in turn alter or transform. ... Rainforests are the most biodiverse ecosystems on earth Biodiversity or biological diversity is the diversity of life. ... This page is a candidate to be copied to Wiktionary. ... Earth science (also known as geoscience, the geosciences or the Earth Sciences), is an all-embracing term for the sciences related to the planet Earth. ... Biota is the plant and animal life of a region or area. ... The worlds oceans as seen from the South Pacific Oceans (from Okeanos, Greek for river, the ancient Greeks noticed that a strong current flowed off Gibraltar, and assumed it was a great river) cover almost three quarters (71%) of the surface of the Earth, and nearly half of the... Geosphere is a term denoting the solid body of the Earth (i. ... Layers of Atmosphere (NOAA) Air redirects here. ...


Other Notes

At least three works of fiction use the Gaia hypothesis as a central part of the plot. The film Final Fantasy: The Spirits Within, arguably contains a fictional parallel to Sir James Lovelock in the character of Dr. Sid, who is met with skepticism from the scientific and social community when he promotes the idea of a "living Earth". In the film, Dr. Sid attempts to create a "waveform" from the positive energy signature of the Earth's spirit, in order to combat the films antagonists, the negative energy "Phantoms", through use of phase inversion canceling. Final Fantasy: The Spirits Within is a science fiction movie by Hironobu Sakaguchi, the creator of the Final Fantasy series of video games. ... James Lovelock in front of a statue of Gaia in 2000 Dr James Ephraim Lovelock CH CBE FRS, (born July 26, 1919) is an independent scientist, author, researcher and environmentalist who lives in Cornwall, in the south west of Great Britain. ... A phase inversion is the introduction of a phase difference of 180° into a waveform. ...


In Lovelock (1994), a novel by Orson Scott Card & Kathryn H. Kidd), Gaiaology is a fully-fledged interdisciplinary science which will soon be put to use by the Earth's first interstellar colony ship. Assuming the target planet will need terraforming, the job of the ship's Gaiaologist will be to integrate the terrestrial species needed for the colonists' survival with the planet's existing ecology. The Gaiaologist's "Witness," a form of assistance animal whose job it is to record every waking moment in the life of such a prominent member of society, is the central character of the book, an enhanced Capuchin monkey named after Sir James Lovelock. Lovelock (1994), a novel by Orson Scott Card & Kathryn H. Kidd) is set in a near-future where mankind is preparing to send out its first interstellar colonization ship, the Mayflower. ... 1994 (MCMXCIV) was a common year starting on Saturday of the Gregorian calendar, and was designated as the International Year of the Family and the International Year of the Sport and the Olympic Ideal. // Events January Bill Clinton January 1 : North American Free Trade Agreement (NAFTA) goes into effect. ... Orson Scott Card (born August 24, 1951) is a prolific and best-selling author working in numerous genres. ... Kathryn H. Kidd was Orson Scott Cards co-author in writing a novel named Lovelock. ... Artists conception of a terraformed Mars in three stages of development. ... The term capuchin can refer to: the capuchin monkeys, genus Cebus, a group of highly intelligent New World monkeys. ... James Lovelock in front of a statue of Gaia in 2000 Dr James Ephraim Lovelock CH CBE FRS, (born July 26, 1919) is an independent scientist, author, researcher and environmentalist who lives in Cornwall, in the south west of Great Britain. ...


The Gaia hypothesis was also used as a central theme in the novel Portent, by James Herbert, in which Lovelock is mentioned by name.


Maxis has specifically named the Gaia hypothesis and Lovelock as inspirations for their 1990 game, SimEarth. A color version of the Maxis logo, used since 1992 Maxis Software was founded as a video game developer and is now a brand name of Electronic Arts (EA). ... SimEarth: The Living Planet is a simulation computer game designed by Will Wright and published in 1990 by Maxis, in which the player controls the development of an entire planet. ...


Fritjof Capra in his fourth book The web of life too has used Gaia theory to explain the complications and interconnections in the marvellous web of life. Dr. Fritjof Capra – photo by Kate Mount Dr. ...


See also

An arcology is an extremely large habitat or settlement, sufficient to maintain an internal ecology as well as an extremely high human population density. ... Climate engineering is a term coined by the Global Commons Institute to mean the sundry assortment of proposals to, for example, deflect solar radiation with mirrors or seed the oceans with massive amounts of iron filings. ... The Earth Charter is a declaration of international values and principles thought to be necessary for building a just, sustainable, and peaceful future. ... It has been suggested that this article or section be merged into environmentalist. ... Elisabet Sahtouris is an American/Greek evolutionary biologist, futurist, business consultant, event organizer and UN consultant on indigenous peoples. ... Gaia is a fictional planet described in the book Foundations Edge, by Isaac Asimov. ... This page is a candidate to be copied to Wiktionary. ... Industrial ecology is the shifting of industrial process from open loop systems, in which resource and capital investments move through the system to become waste, to a closed loop system where wastes become inputs for new processes. ... James Kirchner is professor of Earth and Planetary Science at University of California, Berkeley. ... The noosphere can be seen as the sphere of human thought being derived from the Greek νους (nous) meaning mind in the style of atmosphere and biosphere. Just as the biosphere is composed of all the organisms on Earth and their interactions, the noosphere is composed of all the interacting minds... Also called Od [õd] and Odyle, Odic Force is the 19th century name given to a hypothetical vital energy or life force that proponents say permeates all living plants, animals, and humans. ... The twelve leverage points to intervene in a system were proposed by Donella Meadows. ... SimEarth: The Living Planet is a simulation computer game designed by Will Wright and published in 1990 by Maxis, in which the player controls the development of an entire planet. ... Cover by Oscar Chichoni for the Spanish edition Solaris is a science fiction novel by StanisÅ‚aw Lem (1921-2006), published in Warsaw in 1961. ... Technogaianism (a portmanteau word combining techno for technology and Gaia for the Earth Mother of Greek mythology) is the stance that advanced technology can help restore Earths environment, and that developing such technology should therefore be an important goal of environmentalists. ... Urban ecology is the subfield of ecology which deals with the interaction of plants, animals and humans with each other and with their environment in urban or urbanizing settings. ... Vladimir Ivanovich Vernadsky (Владимир Иванович Вернадский) (March 12, 1863, N.S. [ February 28, O.S. ] – January 6, 1945) was a Russian mineralogist and geochemist who first popularized the concept of the noosphere and deepened the idea biosphere to the meaning largely recognized by todays scientific community. ...

References

  • Anonymous (2006). The Independent. on-line article, 16 January 2006.
  • Kleidon, Axel (2004). Beyond Gaia: Thermodynamics of Life and Earth system functioning. Climate Change, 66(3): 271-319.
  • Lovelock, James (????). Gaia: A New Look at Life on Earth ISBN 0192862189
  • Lovelock, James (1995). The Ages of Gaia: A Biography of Our Living Earth ISBN 0393312399
  • Lovelock, James (2001). Homage to Gaia: The Life of an Independent Scientist ISBN 0198604297
  • Lovelock, James (2006). The Revenge of Gaia: Why the Earth Is Fighting Back - and How We Can Still Save Humanity. Allen Lane, Santa Barbara (California). ISBN 0713999144..
  • Margulis, Lynn (1998). Symbiotic Planet: A New Look at Evolution. Weidenfeld & Nicolson, London. ISBN 029781740X.
  • Staley, M. (2004). Darwinian selection leads to Gaia. J. Theoretical Biol., 218(1): Staley abstract
  • Stephen H. Schneider, et al.,(Eds) (2004), Scientists Debate Gaia: The Next Century ISBN 0262194988
  • Thomas, Lewis (1974) Lives of a Cell
  • Turney, Jim (2003). Lovelock & Gaia. Signs of Live. Icon Books UK, Cambridge. ISBN 1840464585.
  • Volk, Tyler (1997). Gaia's Body: Towards a Physiology of the Earth ISBN 0387982701

External links

  • Earthdance by Elisabet Sahtouris
  • The Gaia Hypothesis proposed by Dr James Lovelock & Dr Lynn Margulis
  • Gaia and Thermodynamics
  • The Gaia Hypothesis
  • Gaia Theory: Science of the Living Earth
  • Keep a positive attitude Comment by Peter van Vliet of the iNSnet Foundation on Dr James Lovelock's article in The Independent of January 16 2006

  Results from FactBites:
 
Gaia theory (science) - Wikipedia, the free encyclopedia (4443 words)
The Gaia hypothesis forms part of what is scientifically referred to as earth system science, is a class of scientific models of the geo-biosphere in which life as a whole fosters and maintains suitable conditions for itself by helping to create an environment on Earth suitable for its continuity.
This theory is based on the simple idea that the biomass self-regulates the conditions on the planet to make its physical environment (in particular temperature and chemistry of the atmosphere) on the planet more hospitable to the species which constitute its "life".
Ecologists generally consider the biosphere as an ecosystem and the Gaia hypothesis, though a simplification of that original proposed, to be consistent with a modern vision of global ecology, relaying the concepts of biosphere and biodiversity.
  More results at FactBites »

 
 

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