Talk:Gaia hypothesis/Archive 2

Archive 1

Archive 2

Archive 3

Misc talk

EofT writes: "Not to be hasty, but, "science textbooks" are not the last word here. The general idea of a Gaia theory goes back a long way and includes some very early spiritual and cognitive views. Johannes Kepler, ....instance had very specific ideas of what it meant for a biosphere to be like organism, or part of a whole universe that was like one, or for us to live inside either (biosphere or universe)."

No one disputes this. I was only talking about how this article should be organized. RK 20:16 4 Jun 2003 (UTC)

EofT writes "Western biology and ecology as now understood do not "own" the concept of "Gaia" or a "theory" about it. It would be scientism to claim that they do. EofT"

There is no such thing as scientism. That word was coined by religious fundamentalists who did not understand how science works, and who were scared that science may reveal facts about the world which might challenge some of their preconceived notions. This word is also now use by radical pseudo-philosophers ("deconstructionists") who showhow imagine that science doesn't actually tells us about the world we live in, but that their literature somehow mysteriously can produce such truths. Some scientists, skeptics and humanists see this word as an ad-homenin attack against anyone who uses the scientific method to learn about the world. RK 20:16 4 Jun 2003 (UTC)

Your view seems, itself, to be [[scientism]: science having monopoly on truth. EofT

EofT writes "The danger is that the merged article will then lose all this context and be censored down strictly to the issues Lynn Margulis and other scientific ecologists talk about."

What danger is this? I don't see anyone refusing to discuss these concepts. All I see are some people who wish to distinguish how scientists use this term. BTW, no traditional religion used the term "Gaia theory" in their cosmology or mythology. You are seeing an example of religions grabbing onto the terminology of a new scientific concept, and trying to claim "this is what we taught all along". RK 20:16 4 Jun 2003 (UTC)

The name Gaia is itself religious terminology appropriated by science. There are similar goddesses or Earth Mother figures in most religions. EofT

EofT writes "It is really hard also to separate this from similar issues in evolution - maybe a revisiting of all those articles is also required, as there seems to be no gaia theory that is not ultimately talking about evolutionary concepts."

I agree that some forms of the Gaia idea may be necessary for evolution to have occured, and this really should be discussed in the appropriate articles here on Wikipedia. Many college textbooks already do this. RK 20:16 4 Jun 2003 (UTC)

College textbooks don't have the unique answer, and neither do have scientists. Which is also a quite improper comment as I am one. What you are currently doing is called censorship of points of view which don't fit your. I would also call that refusal to discuss and properly cooperate. Ant

You are paranoid. No one here, let alone I, is censoring any point of view in these articles. That charge is a flat-out lie. I am only pointing out that you are making up bizarre names for these theories that no one else in the world uses. Worse, you are cutting apart a scientific article on Gaia into three separate articles, using a bizarre uppercase and lowercase spelling system, which violates all Wikipedia naming conventions. RK 23:28 4 Jun 2003 (UTC)

I don't own these articles more than you do. I am ready to discuss changes. And when we come to an agreement, that changes are made. But here, you are just pretending everyone is agreeing with you, when you are in fact alone. And you are refusing to discuss anything at all. This is not an acceptable behavior imho. ----

I have a totally crazy idea. How about we call this article (the one with a capital T) Modern Gaia theory. This is the way it's referred to in Gaia theory, and clearly the word "modern" is general enough to encapsulate the fact that this is probably the most scientific branch of Gaia theory to date. Whether it starts with Margulis or Lovelock I don't really care, but I think it's definitely a better title than (homeorhetic) or (Marguils') or whatever. Thoughts? -- Wapcaplet 20:54 4 Jun 2003 (UTC)

And, as if this page is not large enough already, here's a pretty good article that covers most of modern Gaia theory:

http://www.gaianet.fsbusiness.co.uk/gaiatheory.html

-- Wapcaplet 20:59 4 Jun 2003 (UTC)

I ask time for consideration. You asked for links. Here is one you might look at from the library of Arizona State University (where I spent some time).

http://www.asu.edu/lib/noble/earth/gaia.htm

<snip>

---

I like the general division, but propose putting all the soft-science stuff (Gaia theory analogs), plus the social groups (Gaians) under "Gaia theory (social)", with "Gaians" as a redirect to that page. The rest seems sensible.

I'm happy things are converging.

Steve Rapaport 19:02 8 Jul 2003 (UTC)

---

How about uniting Gaia theory (science) and Gaia hypothesis as Gaia (science)? --Eloquence 03:05 18 Jul 2003 (UTC)

It would be unfortunate to make entirely disappear the names given to these scientific works, known under hypothesis for Lovelock initial work and theories in a more general sense.

I think it also interesting to keep a short and simple (sort of) article on Lovelock hypothesis for clarity. This one being a more thorough background of all works and backup of this set of theories. User:Anthere

I am *really* not thrilled at all by the idea of writing it is a mathematically based theory. Anthère

But my impression is that everything that's called a "Gaia theory" in the sciences is something people run on a computer, which they can do because the theories define the relationships between living things and the environment mathematically. It seemed to me "mathematically" was the ideal way to distinguish a "Gaia theory" from a "Gaia philosophy." Why does "mathematically" bother you?168... 22:14, 5 Nov 2003 (UTC)

Did Lovelock actually hypothesize that the living matter of the planet functioned like a single organism? Or did he rather discover evidence that it does? (i.e. by running his computer model) I'm thinking that Lovelock didn't build self-regulation into the model, but that probably he defined only the direct relations between unit components in his model. Then the idea of life regulating the Earth is a wholistic thing that would have emerged and that he would have seen when he typed "run." That's just my intuition. Does anybody know? Note that under this interpretation of what Lovelock did, his original "Gaia hypothesis" is just that the simple model (in which life really does control the conditions for itself) is like the complex Earth, which is sort of a trivial and obvious hypothesis that every modeler makes about the thing he or she is modeling. I've always thought this term "Gaia hypothesis" undermined the credibility of Lovelock's idea, because it suggests he simply cooked it up or pulled it out of the air, and that he made no test of it. To the extent his idea has been accepted, I'm sure it's because of tests and evidence more than because people like the sound of it. 168... 16:48, 6 Nov 2003 (UTC)

Most of what has been done scientifically with respect to Gaia or theories of Gaia, have not been mathematical (or more precisely computational) at all. Lovelock's first 1979 book was written entirely before the famous Daisyworld model of Watson and Lovelock, which was published around 1983 or so, I believe. If you've read Gaia (1979), you'll find that he did marshall his evidence as done any scientist would, mostly drawing on empirical work including looking at variation in the increase or decrease incoming solar radio levels was buffered by mechanisms unknown and hypothesised to be a feedback effect. This was then backed up by detailed analysis of temperature records from stratigraphy. He was mainly puzzled by these kinds of anomalies, and his experience in helping design various detection mechanisms for NASA. Of course, other hypotheses to account for these observations were possible, and are still debated, Lovelock was really attempting more of a synthesis of all the evidence that he had, and as such, he was presenting a case for a new research direction as well as a specific "hypothesis". Lynn Margulis's take has also been non-mathematical and empirical in nature (see her late 1990s book, Symbiotic Planet). Computer models came later, the initial motivation was most definitely empirically driven.

The distinction between "discovery" and "hypothesis", is largely moot, because in practice scientists don't really sit around "hypothezing" out of thin air, then immediately go the bench to test when they like the idea enough. Nor do they walk into the lab and look at a dish (discovery of Penicillin and radioactivity, are the exceptions that prove the rule) and say, look I "discovered" something in there, I wonder what it can be. It's always a constant too and fro between the two modes of activity and it's rarely possible to completely separate them, scientists typically have some idea about how something works, and are looking for patterns to fit that, which are modified by discovery of new patterns and so on. You never really start with a clean slate. --Lexor 09:55, 7 Nov 2003 (UTC)

Funny, you basically say here what I finally wrote this morning. Essentially. I will add my feeling anyway.

I will try to explain. I have though of several ways, but none appears clear to me. So, I'll do it another way, by somehow personal experience. In the field I studied and work now, these relationships between living things and the environnement, and impact of one on the other, and reversally, are not questionned, because they are just thought obvious somehow. Gaia theories are very little discussed and known in France, because it is very much an english work. However, it can't escape me that the concepts (not the strongest ones, but certainly much more than just the weaker theory) are just those that are taught at university level and widely admitted.

Those fields I know, rely very little on mathematics. They rely first on observation. After lengthy observations, people try to draw hypothesis, and usually check these hypothesis in the field. Sometimes, they make models and compare model results with observations, but that is not so frequent. Ecology for example is first of all a science of observation. Models came next. Agronomy, very developped in my country, uses very few models. Very empiric stuff. Geology is also first before anything a science of observation. You do not practice it well sitting in front of a computer.

I do not think everything called a Gaia theory in sciences is something people run on a computer. It is not the theory that define relationships between organisms and environment, it is observation, first. Mathematics does not explain everything.

As Lexor said, there were several years between the moment Lovelock stated his first hypothesis, and the moment he published the DaisyWorld model. Nearly 20 years I think. I think most of his initial hypothesis came from observations, and very likely from discussions with experts of very various fields. For a good deal of the hypothesis rely on biological and geological considerations. As I understood, a good deal of the noise that followed was due to the fact it was uniting perspectives from different disciplines at the same time. The theory (then perhaps a bit based on some mathematical consideration, but mostly observations, definitly not on modelling) was attacked because people challenged the fact the action of all the living organisms could be planned somehow. They also said it could not be foreseen how feedback loops could help stabilizing the system (which is a rather strange comment to me, because the ecosystems stabilisation was already a known concept), because the new definition of what was "alive" was irrelevant (I think there still is debate here to say what is alive to what is not), and of course because he could not "prove" it (which is quite funny considering the number of scientific facts only "proved" till they are refuted, but anyway...).

To answer them, Lovelock created (many years later) the daisyworld model. It could not answer all criticism, but was meant to prove the activity of living beings could indeed influence, stabilize an environment, for it to be the most favorable to their existence...without necessarily involving consciouness. This was the strongest mathematical base.

I reflected the following points, that I offer to you. This is geological knowledge. I suppose Lovelock used this, though most papers seem to reference to later times in Earth story.

When all the planets of the solar system were created by little dust accretion, there was initially an atmosphere around all of them. The initial (we say primordial, I don't know the word in english) atmosphere was the exact replica of the composition of gaz in the solar system in terms of proportion. There were mostly hydrogen, CO2, a bit of N and some water. Not much. 2 criterias oriented what happened to the atmosphere. If the planet was very near the sun, the gaz were vaporised. That is the case of Mercure where all atmosphere is gone. If the planet was too small, gravity did not permit to keep the atmosphere. Gaz just went away. Venus, which is far away enough and big enough kept most of it, only lost some of the H I think. Jupiter probably lost extremely little. Mars lost most of it because it was too small. But from the planets which kept the atmosphere, only the Earth drastically changed it. All the other ones evoluted in direction that can be explained only by temperature and density.

This was known when Lovelock worked with Nasa probably. They had possibility to analyse gaz composition (roughly) from other solar system planet.

Lovelock had to work to help "guessing" whether there was life on Mars. At that point, he considered the main difference between Earth and the other planets, was that Earth atmosphere was perfectly illogical, because the predominant gaz were not at all in the proportion and concentration in the original atmosphere. With the knowledge we have of what life is, we know that all life we know exchange elements with its environnement.

What mostly changed for Earth was that most CO2 disappeared, and a lot of oxygen (there was basically none initially) appeared.

Nothing really happened from an atmospheric pov initially, because CO2 does not dissolve well at high temperatures. As soon as temperature was low enough, CO2 could dissolve in it. That CO2 was then slowly trapped by several means.

• First through photosynthesis, as soon as 2.8 or 3 billions years. Perhaps even sooner. Most of this CO2 was transformed as C in organic matter. Very early.
• Second biggest trap was through calcareous tests. Calcareous tests are made of CaCO3, and could not occur until Ca was in reasonnable quantities in water. The calcium dissolved in water came from weathering rocks, water sweeping over the continents. The amount of Ca in water was not high until about 2 billions years. And in any cases, most life with calcareous tests appear much much later. Only stromatolithes, which appeared around 2.8 or 3 billions years had CaCO3.

Consequently, the biggest part of CO2 which disappeared initially was due to photosynthetic activity. Activity producing oxygen, slowly building up in the atmosphere, but really seriously increasing around 2.2 when life exploded. And only when oxygen level started being reasonnably high could aerobic life, more efficient start. It is entirely life which created the current atmosphere; that no other planets have.

How do we know ? Models ? No, not by models, though models are nice to complete holes. We know because of observations, indirect observations. We know when oxygen started to really build up in the atmosphere, because around 2.2, sedimentation of FeCO3 (which is Fe2+) switched toward a sedimentation of iron oxydes (with Fe2+ and Fe3+). this indicates a major change in atmospheric conditions. We also know by these huge iron precipitations that occured between 1.8 and 2.5. And we know about the CO2 being trapped as carbon in organic matter, because of the great accumulation of coal very rich in organic matter in Russia and Gabon, around 2.2. We know calcareous sedimentation had an impact much later, because the fossils accumulated much later at the bottom of the oceans. The arguments Lovelock give about the coccolithophores are very interesting in that sense, but that is already quite late in story. Anyway, I just wanted to say (mostly :-)) that these are sciences that certainly use models at some point or another, but to say those are based on mathematics is, sorry, grossly misleading. Lovelock essentially did (I think) a gathering of all what available by then (because the disciplines of geology, biology, ecology, pedology, climatology etc...) were much more walled than what they are right now; and drew conclusions from what could appear soon as "evidence". Of course, he added some interpretations, that are still controversial (and little likely to be ever proved or rejected ihmo). The models were attempt to answer some criticisms.

Sorry, if I was not clear. Horrible english :-) But I had little time these days. Just wanted to try to explain why I cannot accept to see that Gaia theories are based on mathematics. I know that Lexor explained it much better, but I was the one who refused this assertion, so had to explain :-) Anthère

Wow. That's about the most thorough answer I've ever gotten. Obviously, I didn't know about all the work the preceded the modeling and didn't appreciate either how important the evidence from the field was and continues to be. It's a very interesting story, and thanks to both of you for doing me the favor and summoning the patience to tell it to me.168... 17:14, 7 Nov 2003 (UTC) (P.S. "primordial" is the English word too)

Well, *that* probably is a miracle that you understood me. Reading me again, I do not understand myself :-) Anthère

There is something wrong with data. 83 and 88. I will fix later the article. Anthère

Was Lewis Thomas so influencial to be cited in the introduction while others are not ? Should Thomas be listed here as a major influence in the scientific field on Gaia theory ? I regret here the article on the Gaia hypothesis per Lovelock only that RK blanked. I feel like reviving it :-) Anthère

you were gentle 168. I was thinking of entirely removing it. I am not sure it should be part of "science" really. Ant

Well, I felt strongly that that material fit badly in the intro, and your post suggested that you weren't any fan of that positioning either, and so I moved it. I didn't want to do anything more drastic because yours was the only post and you didn't seem to condemn the content all together. I don't feel strongly about it one way or the other, although as I remarked in the subject line of my edit I don't know that the Thomas quote really has a place anywhere in the article, unless it's in a new section for "that kind of thing" (i.e. whatever that kind of thing is. what did I call it? modern parallels?). 168... 06:13, 10 Nov 2003 (UTC)

What I found about the book suggests that it is more a collection of philosophical ideas, with the scientific background of a physician. It depends whether this article is supposed to be Gaia hypothesis as perceived by scientifics, or scientific basis for Gaia hypothesis. If the former, it fits here, but then the article could soon become a collection of opinion by the various scientific people who have given it a bit of thought. If the latter, my belief is that it does not belong here really.

My opinion is that the article is about the second option, but not knowing neither this guy, nor the book, I am not sure he actually brought scientific arguments for or against the hypothesis. Even if he did, the citation ihmo is of little interest and should be removed or should go to the Gaia theory (philosophy). I would like other opinions though. Anthère

Gaia_theory_(science) page

Disclaimer: Just stumbled onto this page looking for biogeography stuff and don't know what this is all about but..:

"Gaia hypothesis led to the new science called biogeography, or even geophysiology, which take into account the interactions between biota, the oceans and the atmosphere."

Waidaminute there. Take a look at this link: http://www.wku.edu/~smithch/biogeog/

With that I just wanted to say that biogeography was around some time before the Gaia theory. Further, biogeography has nothing to do with Gaia theory. Geophysiology is not my area of expertise but I'm pretty certain that too did not sprout out of the Gaia theory.

Hope I have been of help. ErikW

PS. Props on a truly amazing site!

Feel free to bring any correction you feel suitable to that page Erik :-) SweetLittleFluffyThing 17:48, 2 Mar 2004 (UTC)

You mean I can edit the encyclopedia myself? Witohut even being registered?

What are you doing right now ?

Heh, cool! Unfortunately though, I thought Gaia was esotheric drivel. I'm not qualified :P

ErikW

esotheric drivel ? Head to Gaia (philosophy)... SweetLittleFluffyThing

Gaia hypothesis

Since when is this a theory? Last I checked it was still a hypothesis with little empirical support, and still regarded as speculative by most ecologists. Guettarda 01:52, 10 Dec 2004 (UTC)

it depends on whether you consider the weak or strong versions. Some aspects of it are obviously not regarded as speculative at all. SweetLittleFluffyThing

Gaia hypothesis in ecology

After initial criticism, Gaia hypothesis is now considered an essential part of ecological science, proposing the planet to be the object of ecological study. Most ecologists agree to assimilate the biosphere to a super ecosystem and consider this hypothesis, though a simplification, is consistent with the modern vision of global ecology, relying the concept of biosphere and biodiversity.

This statement is inaccurate, especially without qualification.

• There is no single Gaia hypothesis, but a number of related hypotheses. Many ecologists are unaware of the later definitions put forward by Lovelock, and are only aware of his original "superorganism" view. Few ecologists take this seriously, and thus, it could not be said that most ecologists support Gaia.
• Among those whose views (consciously or unconsciously) are influenced by Lovelock's hypothesis, many are unwilling to associate their views with the baggage associated with the early forms of the hypothesis.
• Many ecologists simply ignore the whole debate as irrelevant ot them. As recently as 2003, Wilkinson (a pro-Gaian) makes the point that Daisyworld models have had almost no impact on the ecological literature, and thus, on mainstream ecological thinking.

Gaia remains highly controvertial. Most would agree that Lovelock's ideas about coupling biological processes with climatic and geological processes, and his ideas about emergence have not profoundly altered scientific thinking (those who would disagree suggest that these things were already anticipated by the development of biogeochemistry by Hutchinson and his students), but many of the observed feedback cycles work in precisely the opposite way that Lovelock anticipated (e.g., DMS, methane and carbon dioxide all function as positive feedbacks on climate, making warm periods warmer and cool periods cooler).

On the other hand, some of the modern re-workings of Gaia (weak Gaia) are little more than statements of the obvious - they have been weakened to the point where it is unable to make a priori predictions, and thus is useless as a hypothesis generator.

Finally, there is no satisfactory reconcilliation between Gaia and Darwinian evolution (although there have been some tentative attempts). Given the centrality of Darwinian evolution to biology (and the overwhelming weight of evidence in support of it), "acceptance" of Gaia among ecologists is unlikely until either there is a theoretical reconcilliation or Darwinian evolution is displaced. Guettarda 22:26, 12 Dec 2004 (UTC)

Gaian concepts ... generated an environmental literature ... that extends far beyond the bounds of the traditional relevant subfield of biology: "ecology." Ecology as taught in academic circles has become more Gaian or has faded away. Lynn Margulis, 2004, Gaia by Any Other Name, in Scientists Debate Gaia, the MIT Press ISBN 0262194988

Seems that Margulis disagrees a bit with your statement above. The book also addresses some of your other points, Gaia and evolutionary theory and the feedback problem. Perhaps Gaia remains highly controversial to reductionist turf defenders, but not to all scientists.

Wake up and smell the daisies :-) -Vsmith 04:23, 13 Dec 2004 (UTC)

Sorry, library's copy is checked out. It isn't helpful to be insulting. I have no turf to defend here - I'm a community ecologist, it doesn't affect my work one way or the other (unless Neodarwinism is wrong, in which case I would have to revise my philosophy, but not my conclusions). I have no axe to grind - I did look at everything I could find in the peer reviewed literature and the consensus there was what I put into my question/comment. I would add though, that I have never met anyone who espouses support for the Gaian point of view.

I made the effort to read both supporters of Gaia (Wilkinson, Kleidon, Lenton, Lovelock - who unfortunately seemed to be more interested in insulting people than clarifying issues), people who appeared to be in the middle (Schneider) and opponents (Kirschner, Volk) in trying to figure out this question. All admitted that there was real controversy. Vsmith's response brings to mind a quote from Popper (1963) in Kirschner (2003: Climate Change 58: 21-45) -

These theories appeared to be able to explain practically everything that happened within the fields to which they referred. The study of any of them seemed to have the effect of an intellectual conversion or revelation, opening your eyes to new truth hidden from those not yet initiated. Once your eyes were thus opened you saw confirming instances everywhere: the world was full of verifications of the theory. Whatever happened always confirmed it. This its truth appeared manifest; and unbelievers were clearly people who did not want to see the manifest truth?(Popper 1963)

Can you answer any of the questions rather than being insulting? Guettarda 17:42, 13 Dec 2004 (UTC)

Insulting?? I did answer one of your points with the quote from Margulis. I apologize if you took my bit of sarcasm and/or humor as a personal insult. It was not intended as an insult in any way, just a comment on a common problem in academia. The daisies bit was supposed to be humorous and general. -Vsmith 21:17, 13 Dec 2004 (UTC)

Yep, it's insulting to call someone's professional ethics into question.

As for the Margulis quote, it doesn't answer any of my questions about Gaia, it merely says that my Darwinian-influenced view of the world will fade away. Maybe true, but it doesn't answer the questions raised. In essence, a cell biologist tells ecologists that they are too full of themselves (presumably for doubting her). That certainly does not refute my assertion that the Gaia hypothesis is not accepted by most ecologists.

• Gaia requires "group selection" to an extent that is incompatible with Neodarwinism. I am unaware of ecologists/evolutionary biologists abandoning Darwin, and I don't see people who fail to do so as "turf defenders". If Margulis answers this, I am interested (and disappointed that this major breakthrough in group selection has not been more widely reported in the literature - it should have made the front cover of Science - did I miss that?)
• As pointed out by Kirschner, the feedback loops that have been quantified seem to go more strongly in the opposite direction of what Gaia requires. Has this been dealt with? Can we stop worrying about Global Warming?
• Weak Gaia has moved to the point where it has almost no predictive power. Wilkinson (1999, TREE 14(7):256-257) - One of the main ideas of Gaia theory is that the biotic and abiotic environments are coupled and change together. If it gets down to something as trivial as that there is no Gaia anymore, just the Lovelock-Margulis legacy that has forced biologists, geologists and climatologists to notice one-another. That legacy is valuable, but it is balanced by Lovelock's use of Gaia theory to argue that there was nothing to worry about with respect to ozone depletion.

Without these issues addressed I don't see how it could cease to be controvertial among ecologists. Margulis is free to trivialise ecology, but I don't see how that has won over hoards of ecologists to the cause. Have I been too busy teaching this semester to notice this shift in opinion? Silly me, I thought I was decently well-informed. Guettarda 01:00, 14 Dec 2004 (UTC)

Whoa! Now I called your professional ethics into question - wow, this escalates fast. Bull puppies! Your comments about Lynn Margulis are what I consider to be insulting and absurd (and revealing). She has the seemingly rare ability to see beyond, or outside the narrow blinders of an academic discipline and take the view of system science. It seems to me that she revolutionized cell biology and now is seeking to widen the horizons of all biology. As for neodarwinism, in my view there is nothing sacred about it and it (rather those scientists working with it) perhaps needs to evolve to incorporate the system view and emergent properties that are part of the Gaia concept. Now, I'm just an old geologist who doesn't know much, and am still reading that book, but I recall the furor that the new plate tectonics caused among many traditional geologists in the 60s while I was in college - and I see much of the same entrenchment and reluctance to change among biologists over the last 20 years with respect to the Gaian view. Maybe, after I finish the book, I'll come back and consider some of those issues of yours. And then maybe I won't - I'd probably end up insulting somone's professional ethics with my crude humor. -Vsmith 05:45, 14 Dec 2004 (UTC)

It's a very severe statement to tell someone that they are a turf defender, not a scientist. It implies that I am an unethical scientist, and that implication is based on nothing more than questioning a theory. So I saw your comment as a personal attack. If that was not your implication, then my apologies for taking it wrongly. But that was the way I saw it, hence my request for you not to engage in personal attacks. You can call my ideas ridiculous, you can tell me my statements are out of line. Fine. But to call me a turf defender/not a scientist for questioning a statement that is contrary to my experience, and which disagrees with what I can find in the literature (and I put a day and a half that I could not afford reading the literature on the issue to avoid simply shooting off my mouth. (My first, in the section before this, was simply shooting off my mouth).

I am not saying the neodarwinism is sacred. Like any theory, it needs to evolve, and will probably be replaced by something else eventually. Nonetheless, it is supported by a large weight of evidence which cannot be simply dismissed by "new" ideas. I may be wrong, but plate tectonics won the day by being able to provide a better explanation for the data than the prevailing theory (which was what? stasis?) Granted, I know very little about plate tectonics, but I read what is likely to have been the last serious work of biogeography which tried to explain plant distributions without plate tectonics (largely through the use of several land bridges across the Pacific)...what was once logical will seem laughable eventually.

I am not sure what I said that was "revealing" about my attitude to Margulis. But then, I suppose I wouldn't, since I am not in a position to psychoanalyse my own comments (even a madman makes sense in his own head). As it stands (admittedly, without context) the quote: Ecology as taught in academic circles has become more Gaian or has faded away seems to imply that ecologists either have the choice of falling in line behind Gaia, or being condemned to obscurity (cell biologists have been telling organismal biologists about their impending irrelevance for decades, *shrug*). Science works by consensus - you win by convincing your opponents, not by looking down your nose at them. As for my "insulting and absurd" comments about Margulis...

1. As for the Margulis quote, it doesn't answer any of my questions about Gaia - is it insulting or absurd to say that the quote did not answer my question?

2. Gaia requires "group selection" to an extent that is incompatible with Neodarwinism...If Margulis answers this, I am interested, sure, I followed that up with sarcasm - but all I am saying is that I am unaware that an answer to the problem of group selection, as posed by Gaia, has been answered, and I feel that such a major breakthrough (and it would be a very major breakthrough) would somehow have made its way to me.

3. My third comment acknowledges that the Lovelock-Margulis legacy has had a major impact on how scientists think, especially about issues like emergence and systems science. That fact does not mean that they are right on Gaia (in fact, as originally stated, they appear to have been quite wrong, and Lovelock has admitted as much).

4. Margulis is free to trivialise ecology, but I don't see how that has won over hoards of ecologists to the cause - this might be seen as insulting, but all it says is that trivialising the opposition is not the way you win debates in science. As it stands in your quote from her, it would appear that is what she is doing.

Big changes in science are more likely to come through Kantian paradigm shifts than through Popperian normal science. Nonetheless, when the weight of evidence is against the new paradigm, and the observations can be explained by existing science, then the conservative point of view is logically justifiable. That does not mean it is right. But Gaia theory is older than I am, and despite substantially reducing its claims, it still lacks experimental verification. Daisyworld models have done well to show that a negative feedback between climate and biota can result in co-evolution toward a climate that favours the biota. The problem is that possible isn't good enough, especially in ecology. There are hundreds of ideas which have been shown to be logically plausible and experimentally possible but which turn out to be ecologically trivial. They were touted as revolutionary, strongly defended by their supporters, and have ended up in obscurity. In addition, scientific evolution has been full of fundamentally flawed ideas which have helped science progress.

If Gaia theory turns out to be true, more power to them. I remember loving the idea when I discovered it (in high schol). But as a disinterested party, I see no reason to jump ship until the weight of evidence supports such a shift. The more I learn about Lovelock, the less respect I have for him, though I need to actually read his autobiography, not just skim it and use Schneider's crib notes (review in Science). I have immense respect for what Margulis has done with respect to endosymbiont theory and the whole 5 kingdom approach. But even great minds can be off track - Linus Pauling and vitamin C, for example. I'm not saying she's wrong, and after Christmas I will recall the library's copy and find out what it is that the book actually asserts.

I still stand by my first comment though - I think the statement that most ecologists support Gaia to be at variance with the evidence, as I can find. If it can be supported with a citation, (as statements in Wikipedia are supposed to be), please do so. If not, I don't think it should stand as is. Guettarda 21:59, 14 Dec 2004 (UTC)

• There is no single Gaia hypothesis, but a number of related hypotheses. Many ecologists are unaware of the later definitions put forward by Lovelock, and are only aware of his original "superorganism" view. Few ecologists take this seriously, and thus, it could not be said that most ecologists support Gaia.
• Among those whose views (consciously or unconsciously) are influenced by Lovelock's hypothesis, many are unwilling to associate their views with the baggage associated with the early forms of the hypothesis.
• Many ecologists simply ignore the whole debate as irrelevant ot them. As recently as 2003, Wilkinson (a pro-Gaian) makes the point that Daisyworld models have had almost no impact on the ecological literature, and thus, on mainstream ecological thinking.

I agree with Guettarda that the most is too fluttery a word and not reflecting the reality/diversity of situations. The three arguments given are correct, to which I would add that Gaia hypothesis is also mostly known and discussed among english-speaking world, and far less in other cultures.

What I would rather agree with is that Most ecologists agree to assimilate the biosphere to a super ecosystem, while the second part of the sentence lacks accuracy for the reasons Guettarda mention.

If I dared suggest... what about adding the three arguments given by Guettarda in the text ? These are much better reflecting the reality.

The final text would be

Most ecologists agree to assimilate the biosphere to a super ecosystem. However,not all of them would agree to say the Gaia hypothesis, though a simplification, is consistent with the modern vision of global ecology, relying the concept of biosphere and biodiversity. First, many ecologists are unaware of the later definitions put forward by Lovelock and are only aware of the original "superorganism" view, which is generally not taken seriously. Besides, among those whose views (consciously or unconsciously) are influenced by Lovelock's hypothesis, many are unwilling to associate their views with the baggage associated with the early forms of the hypothesis. Finally, many ecologists simply ignore the whole debate as irrelevant ot them. As recently as 2003, Wilkinson (a pro-Gaian) makes the point that Daisyworld models have had almost no impact on the ecological literature, and thus, on mainstream ecological thinking.

What do you think ? - user:anthere

Say that with pride, guys

I see a more than a bit of back and forth in the discussion above, but all of you that contributed to this article have something now to be proud of. In an article titled "The So-called Gaia Theory" (Skeptical Inquirer, 29(3), May/June 2005) Massimo Pigliucci (p. 21) makes this statement:

....(quoted at http://en.wikipedia.org—a good, neutral introduction to the theory and controversy);....

Wow! For those of you unfamiliar with Skeptical Inquirer, I can only tell you that it is very exciting to me as a scientist to see that the likes of M. Pigliucci considers Wikipedia worth his time to visit, read, AND mention! - Marshman 02:44, 7 May 2005 (UTC)

categorization

Gaia theory could feasibly be put into a number of categories in the Earth sciences, however I have added it to the parent category:Earth sciences as Gaia is interdisciplinary. --Vincej 16:33, 30 July 2005 (UTC)

Gaia as a life form

While the Earth as a unit does not match the generally accepted biological criteria for life itself (Gaia does not reproduce, for instance), many scientists would be comfortable characterising the earth as a single "system".

The argument that "Gaia does not reproduce" is either weak or outright faulty. There is some amount of evidence that life on the Earth was brought here on comets, so Gaia may be a "child" of life elsewhere (panspermia), and may by that process produce other planets with life. Another, non-falsifiable, argument is that mankind is in the early stages of exploring the universe and will someday soon start colonizing other planets.

I would suggest either use some other argument that Gaia is not alive, or mention these points in the article.

--zandperl 23:33, 29 August 2005 (UTC)

I second that. ObsidianOrder 00:11, 30 August 2005 (UTC)

The dispersion of any species is a part of its reproductive strategy, but few complex systems reproduce by dispersion (an interesting thought, though). Neither point brought forward here (panspermia or humans exploring the universe) rises to the level comparable to species or organism reproduction and therefore cannot support such an interpretation for Gaia as a superorganism. To do so is not far from declaring that Ford motor cars reproduce because, gosh, there always seem to be new ones out on the road. - Marshman 04:05, 30 August 2005 (UTC)

rises to the level comparable to species or organism reproduction

Can you quantify what that means? What I think you're saying is that panspermia doesn't happen frequently enough for us to say that a biosphere is reproducing. If that's what you mean, I disagree. An amoeba would think that a redwood or saguaro doesn't reproduce frequently either. --zandperl 04:16, 30 August 2005 (UTC)

Systems are complex things comprised of many parts. To say a system reproduces, at whatever frequency, implies that a very similar or identical system will arise from that reproduction. That is not the same as dispersion in biology. No part of Gaia as an "organism" can point to a reproductive unit that would in any sense disperse and reproduce the system in another place. To say that life may disperse is arguable off this planet, but certainly within the realm of possibility. To say that the system will reproduce itself is absurd. We (as humans) cannot get ecosystems to "reproduce" on earth. Whatever units of life are dispersed to other planets by us or independent of us could possibly evolve into other complex systems. That is not reproduction. I suspect that those who would argue a superorganism reproduces are simply not being very specific about their terminology. In esence, this seems to be an argument about the dispersal of life throughout the universe. If you want to call that "reproduction" be my guest; but it is not reproduction in a biological sense. - Marshman 04:47, 30 August 2005 (UTC)

At present there is zero scientific evidence to support even weak Gaia hypotheses. Similarly, there is zero evidence for panspermia. That does not mean that they are false, but you cannot, in the realm of science, do anything more than speculate. Assuming for arguments sake that the idea of a superorganismal Gaia is reasonable, in order to "reproduce" it have have to give rise to new superorganisms, new inhabited planets which function as "superorganisms", which self-regulate. Human colonisation of other planets would not qualify any more than Biosphere 2 would qualify unless and until a new self-regulating system was established. Of course, this all pre-supposes that there is such a thing as a superorganismal Gaia. All experimental evidence to date has failed to support the idea of a homeostatic planet. This isn't the same as the amoeba saying that the redwood does not reproduce. An amoeban scientist couild still find evidence that redwoods reproduce...and would still be able to recognise the other characteristics of life. What are the "gametes" of Gaia? Humans? Hmmm...have we just found the "missing designer"? Guettarda 13:34, 30 August 2005 (UTC)

At present there is zero scientific evidence to support even weak Gaia hypotheses. (Guettarda)

(a) No controversy exists, however, that life and the physical environment significantly influence one another. (b) At one end is the undeniable statement that the organisms on the Earth have radically altered its composition. (article)

(a) Do you believe in global warming? If so (or even if not), then you may have seen plots of the atmpsheric CO₂ levels over the past century. The trend is generally upwards, but on top of this is a fluctuation within each year. Environmentalists agree that this is caused by the plant life of the world, as follows. There is more land mass in the Northern Hemisphere than the Southern, and therefore more plants in the north than south. In Northern Hemisphere summer (Southern winter), there are more plants in the world than in Northern winter (Southern summer). Plants take CO_2 out of the atmosphere. Therefore it is no surprise that the yearly variation has less CO_2 during northern summer and more during northern winter. Life (plants) interacts with the physical environment (CO_2 levels).

(b) refers to how primordial organisms created the O_2 currently in our atmosphere.

The weak Gaia theory is believed by most mainstream scientists, though many are not aware of it due to the more well known but less mainstream versions of the theory. --zandperl 15:45, 30 August 2005 (UTC)

I'm unclear where the "argument" jumped to (you did not respond to the points made by either myself or Guettarda regarding reproduction), but I will respond to a couple of your statements. Yes, (a) and (b) are essentially correct and you present reasonable supporting arguments. I do not think anyone is arguing that the "Gaia as a system" is not true; it is "Gaia as a super-organism" that may be stretching things. I think anyone really interested in this approach to understanding life on the planet should delve a deeper into ecosystem theory. Ecosystems are units of the organization of life and the physical environment that would have to show the properties some would ascribe to gaia if gaia were to exist. The reason being: if system properties of ecosystems do not include self-regulation (I think they do to some extent), then either gaia does not show such a property or ecosystems are not "real" units. In other words, either gaia is the ultimate ecosystem, and we can learn about by studying smaller, more manageable units, or ecostystems do not really exist and therefore gaia theory has nothing to offer. - Marshman 18:26, 30 August 2005 (UTC)

My apologies for not being clearer. I thought there was some debate here over whether "Gaia as system" was true. Additionally, I do not personally believe "Gaia as a super-organism," I was simply taking the Devil's Advocate position. I did not respond to the latest arguments by yourself (Marshman) and Guettarda (i.e., panspermia and terraforming do not create true replicas) because they are good points and I have no rebuttal for them - though the amoeba observing tree reproduction makes me wonder if stars can be considered to reproduce through the shockwaves of star death or stellar winds triggering the collapse of nearby molecular clouds and therefore new star formation, but that's a different argument.  :)

--zandperl 20:12, 30 August 2005 (UTC)

I suppose there is a debate somewhere, but looks like we are all preaching to the chior - Marshman

Actually I do disagree with Gaia as a system. Global warming is actually evidence against Gaia, since warming and cooling cycles are examples of positive feedback, which pushes the system away from equilibrium, not negative feedback which the Gaia hypothesis predicts. While theoretic and simulation-based models suggest that Gaia is plausible and possible, none of the predictions made by Gaia theory have been supported experimentally, and in fact most tests of the predictions have not supported the Gaia hypothesis. Of course, since Lovelock keeps shifting the goalposts, it's hard to pin down what the "hypothesis" is.

That said, of course I don't disagree with the whole Earth Systems Science approach, and of course Gaia has influenced the field (for the better, I believe). But as a scientific hypothesis it lacks experimental verification. As for stars reproducing...interesting idea but I wouldn't know where to take it... Guettarda 21:16, 30 August 2005 (UTC)

Well, by extension: ecosystems cannot be bounded, so they are in essence always a part of some larger system (my opinion). Eventually that will lead to the conclusion of the earth being the only reasonably bounded ecosystem; ergo a system. As for all the other requirements of the gaia hypothesis, well you are right, but any system can be pushed to a new state by overwhelming the feedbacks' abilities to return the system to some original equilibrium state. I don't think it removes the earth-life or "gaia" from consideration as a system; but you seem to be saying that as well in your 2nd paragraph. - Marshman 02:26, 31 August 2005 (UTC)