The Earth as viewed from the ISS (NASA)

Gaia Hypothesis: Could Earth Really be a Single Organism?

30 Apr , 2008 by

Can a planet like Earth be considered a single living organism? After all, the human body is composed of hundreds of billions of bacteria, and yet we consider the human body to be a single organism. The Gaia Hypothesis (or popularly known as “Gaia Theory”) goes beyond the individual organisms living on Earth, it encompasses all the living and non-living components of Earth’s biosphere and proposes that the complex interacting systems regulate the environment to a very high degree (here’s a biosphere definition). So much so, that the planet may be viewed as a single organism in its own right. What’s more this hypothesis was developed by a NASA scientist who was looking for life on Mars…

When you stop to think about it, our planet does act like a huge organism. If you look at the interrelationship between plants and atmospherics, animals and humans, rocks and water, a complex pattern of symbiotic processes seem to complement each other perfectly. Should one system be pushed out of balance by some external force (such as a massive injection of atmospheric carbon dioxide after a volcanic event), other processes are stimulated to counteract the instability (more phytoplankton appear in the oceans to absorb the carbon dioxide in the water). Many of these processes could be interpreted as a “global immune system”.

James Lovelock (Guardian.co.uk)

The hypothesis that our planet could be a huge organism was the brain child of British scientist Dr James Lovelock. In the 1960’s when Lovelock was working with NASA on methods to detect life on the surface of Mars, his hypothesis came about when trying to explain why Earth has such high levels of carbon dioxide and nitrogen. Lovelock recently defined Gaia as:

…organisms and their material environment evolve as a single coupled system, from which emerges the sustained self-regulation of climate and chemistry at a habitable state for whatever is the current biota.” – Lovelock J. (2003) The living Earth. Nature 426, 769-770.

So, Lovelock’s work points to interwoven ecological systems that promote the development of life currently living on Earth. Naturally, the statement that Earth itself is actually one living organism encompassing the small-scale mechanisms we experience within our biosphere is a highly controversial one, but there are some experiments and tests that have been carried out to support his theory. Probably the most famous model of the Gaia hypothesis is the development of the “Daisyworld” simulation. Daisyworld is an imaginary planet whose surface is either covered in white daisies, black daisies or nothing at all. This imaginary world orbits a sun, providing the only source of energy for the daisies to grow. Black daisies have a very low albedo (i.e. they do not reflect the sun’s light), thereby getting hot and heating up the atmosphere surrounding them. White daisies have a high albedo, reflecting all the light back out of the atmosphere. The White daisies stay cool and do not contribute to atmospheric warming.
Java applet of the Daisyworld simulation »

When this basic computer simulation runs, a rather complex picture emerges. In the aim of optimizing the growth of daisies on Daisyworld, the populations of white and black daisies fluctuate, regulating the atmospheric temperatures. When the simulation starts, there are huge changes in population and temperature, but the system quickly stabilizes. Should the solar irradiance suddenly change, the white:black daisy ratio compensates to stabilize atmospheric temperatures once more. The simulated Daisyworld plants are self-regulating atmospheric temperature, optimizing their growth.

This is an oversimplified view of might be happening on Earth, but it demonstrates the principal argument that Gaia is a collection of self-regulating systems. Gaia helps to explain why atmospheric gas quantities have remained fairly constant since life formed on Earth. Before life appeared on our planet 2.5 billion years ago, the atmosphere was dominated by carbon dioxide. Life quickly adapted to absorb this atmospheric gas, generating nitrogen (from bacteria) and oxygen (from photosynthesis). Since then, the atmospheric components have been tightly regulated to optimize conditions for the biomass. Could it also explain why the oceans aren’t too salty? Possibly.

This self-regulatory system is not a conscious process; it is simply a collection of feedback loops, all working to optimize life on Earth. The hypothesis also does not interfere with the evolution of species or does it point to a “creator”. In its moderate form, Gaia is a way of looking on the dynamic processes on our planet, providing an insight to how the seemingly disparate physical and biological processes are actually interlinked. As to whether Gaia exists as an organism in it’s own right, it depends on your definition of “organism” (the fact that Gaia cannot reproduce itself is a major drawback for viewing Earth as an organism), but it certainly makes you think…

Original source: Guardian


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LLDIAZ
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LLDIAZ
April 30, 2008 11:47 AM

I believe life is anything that gives off takes in or simply is made up of energy. From our brain waves to a rocks magnetic pull on a compass is all some form of life. I’m open to critics so come on hit me with it….

Loretta Whitesides
Guest
April 30, 2008 5:48 PM

Ian/John,
Great points. Yes, I think that is actually one of the most intriguing ideas of our time. That humanity is the reproductive cells of Gaia and that it is the knowledge we gain of this planet and its incredible ecosystems and the seeds of life itself that we are charged with taking into the universe and making new Earths. I have heard Peter Diamandis discuss this idea before and I am thrilled to see more minds coming to this idea on their own.

Adam
Guest
Adam
April 30, 2008 11:18 AM

Does this theory even attempt to define exactly what “life” is? It’s hard to claim something is living without defining what that means. If you define it as depicted in the article, that means the earth, and millions of other non-living things are living. If you use commonly accepted requirements such as “must produce offspring”, “must adapt to it’s environment”, etc, then it’s a stretch to claim the earth can perform those actions.

Jozef
Member
Jozef
April 30, 2008 11:24 AM

I never really thought of the earth and its organisms inthe same way that our body is made up of living cells…I guess this is putting the term “mother nature” to the test…

Hamy
Guest
Hamy
April 30, 2008 11:28 AM

Quote: “…the fact that Gaia cannot reproduce itself is a major drawback for viewing Earth as an organism…”
How do you know that? Of the 4.3 billion years of planet Earth, we have only experience of a sentient two or three millennia.
We had no concept of sulphur based organisms and would have thought the possibility preposterous until they were discovered… to have had to accept that they could breed would have taxed the credulity a few decades ago. In the expectation of eternity, perhaps Earth hasn’t got around to planning a family yet.
Presume what you wish, but keep it to yourself please.

Al Hall
Member
Al Hall
April 30, 2008 11:46 AM

The Earth a single living organism? I’ve heard this one before… Perhaps, I suppose.. Depending on the definition. But then why not let us go further and say that the whole known Universe is, or part of, a single living organism? All of the building blocks are there (here).

Adam
Guest
Adam
April 30, 2008 11:50 AM

Hamy, are you familiar with the term “burden of proof”? You have the burdon of proof and you are making the presumption in this case.

You could say the earth already has made offspring, the moon. It came from the mating of the earth and an asteroid. You could also say two cars having a car wreck and a bumper flying off is reproduction, therefore the cars are alive.

Al Hall
Member
Al Hall
April 30, 2008 12:06 PM

Here is an old website for those who are interested/bored… It also has a page on the Gaian Hypotheses.

http://library.thinkquest.org/C003763/index.php?page=origin06

John Mendenhall
Member
John Mendenhall
April 30, 2008 12:11 PM

If we terraform a few planets to suit ourselves, has Gaia reproduced?

Kendall
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Kendall
April 30, 2008 12:21 PM

“(the fact that Gaia cannot reproduce itself is a major drawback for viewing Earth as an organism), ”

Actually, think panspermia. Meteor strikes may have caused mass extinction on earth while spreading microbes to other planets.

Then again, consider expansion of humankind into space… “manspermia”? Maybe when we (humanity) are able to settle other planets, our planet will have reached puberty.

Though the planet itself is not reproduced, the shell of life that encompasses the earth can reproduce.

Al Hall
Member
Al Hall
April 30, 2008 12:26 PM

Here is an old website for those who are interested/bored… It also has a page on the Gaian Hypotheses.

library.thinkquest.org/C003763/index.php?page=origin06

Clint
Guest
Clint
April 30, 2008 12:52 PM

I think this is dangerous thinking. If the Earth is one organism, then what if to keep the Earth healthy, it is determined that the “bacterial” entity, human, must be vacinated against? Are we ready for that?

Jason
Guest
Jason
April 30, 2008 1:18 PM

With all of the technology that we are creating we are losing our connection to the universe. Our heart beats are connected to it, our bodies are made of the same materials, we are all one. Nothing on this level of reality is independent of anything else. Everything is one. Check out theories of the holographic universe (robert talton), string theory, documentary called “what the bleep do we know”, or search google or youtube for the esoteric agenda.

Mr. LAME
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Mr. LAME
April 30, 2008 1:56 PM

hell yeah! reminds of south park lice capades !
great ep … :S

Cynthia
Guest
Cynthia
April 30, 2008 2:25 PM

Isn’t the Earth more like an orange covered with fungus floating in free space?

Al Hall
Member
Al Hall
April 30, 2008 3:15 PM

Hmmm.. I like it, but would have to disagree. I think because of plate tectonics it would be more like a rotten mango covered with fungus floating in free space… It’s more squishy… That’s a technical term… smile

Polaris93
Member
April 30, 2008 11:08 PM
Ian — I would differ with you as to the assumption that Gaia can’t reproduce. No less a scientist than biologist Lynn Margulis has pointed out that our efforts to establish ourselves offworld are precisely that: Gaia’s mode of reproduction. We provide the transport offworld, and take a good representative of Earthly life with us, out of necessity, perhaps in mobile habitats carved out of asteroids or that sort of thing. You’re thinking of “little planets” as equivalent to a planet’s babies. But sexual reproduction among multicellular organism involves transfer of genetic material to the eggs of the female, resulting in zygotes which then undero development that culminates in viable young. The female’s egg and male’s sperm look… Read more »
sofista
Member
April 30, 2008 4:45 PM

¿Puede considerarse que la Tierra es un único organismo viviente? Después de todo, el cuerpo humano está compuesto por cientos de miles de millones de bacterias, pero consideramos que el cuerpo es un único organismo. La hipótesis de Gaia (popularmente conocida como “la teoria de Gaia”) va más allá de los organismos individuales que pueblan la Tierra, […] Fuente: Ian O’Neill para Universe Today.

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