Brian likes to emphasize–and I agree–that ecology as a whole lacks what Brian calls a problem solving mentality. We’re too often satisfied with evidence that merely suggestive or consistent with our hypotheses, and we’re too reluctant to permanently discard ideas that are past their sell-by date.
So here’s a question. Actually, two of them:
- What’s the biggest idea ecologists have ever permanently rejected? Define “biggest” in any plausible way you like–most important, most influential, most widely-believed, most widely-studied, most fundamental, most cited, etc.
- How many big ideas have ecologists ever permanently rejected? Can we come up with a complete list? If we can, that would be consistent with Brian’s and my concern–because that would mean the list is short!
Here’s an opening bid: Clements’ notion of communities as superorganisms. Even community ecologists (like me!) who believe species aren’t independent of one another because interspecific interactions matter don’t believe in anything like Clementsian superorganisms as far as I know. And subsequent attempts to revive the idea by talking about speculative possibilities like community-level selection haven’t gotten very far. I suppose there’s an echo of the superorganism idea in the notion that stability constraints “select” for stable communities, but it’s a pretty faint echo.*
Here’s a second bid: “broken stick” models of species abundance distributions. Not all that big an idea in the grand scheme of things. But beggars can’t be choosers–we’ll end up with a really short list if only really big ideas qualify for inclusion.
Hopefully, the list (or lack thereof, if no one can think of any other entries!) will start a conversation about what it takes for an idea to end up on the list. What does it take for ecologists to give up on an idea? What combination of circumstances–features of the idea, the ecologists working on it, the available theory and data, and nature itself–conspire so as to cause an idea to be widely influential in ecology, and then later get permanently rejected?
I predict that at least one comment will be from someone arguing that superorganisms or broken stick models aren’t dead. Thereby confirming the first paragraph of the post. 🙂
*Aside: Here’s a brand-spankin’ new TREE paper by a bunch of sharp people on stability constraints possibly selecting for stable ecological systems. I think it’s an interesting topic that’s worth studying. I think you’ll need to look to microcosms or other appropriate model systems to get decent direct evidence (as opposed to highly indirect evidence that is sorta suggestive if you squint at it, wave your arms, and make lots of really strong assumptions). And I predict that the the effects of selection for stability (using whatever sense of stability you think is most relevant) will turn out to be quite weak to nonexistent in practice, because they’ll be swamped by other factors. But it’d be very cool if I turned out to be wrong about that. See this old post for further discussion.
Dynamic Ecology 
I’d love to read the old post for further discussion but the link is broken (last link)…
Thanks, fixed.
Thanks!
They don’t come much bigger than the Gaia Hypothesis….
Did ecologists ever take that seriously in the first place?
Depends what you mean by “ecologist”. But there were certainly quite a number of environmental scientists and biologists who took it very seriously, and its formulation makes no sense without some ecology – the Wiki entry’s quite informative: https://en.wikipedia.org/wiki/Gaia_hypothesis
Undergrads take it very, very seriously. I am continually amazed by how Gaia their world views can be.
@Meg:
Hmm, interesting. Now I’m curious if our undergrads here think about Gaia at all.
Do you find that their preexisting views about Gaia interfere with their ability to learn what I think of as standard ecological course material?
@Jeremy: They don’t refer to it as a Gaia worldview, but the way they think is very Gaia. For example, a really common misconception is that a mutation needs to benefit the community as a whole in order to spread. As another example, for mutualisms, many think that the organisms are doing it to help each other.
@Meg:
Ok, got it. And I’m surprised. My casual impression of our students is that their environmentalism doesn’t really stray into misconceptions like beneficial mutations benefit the community or mutualists are out to help each other. But it’s just a casual impression, possibly biased by my interacting most with our more experienced and better students.
I call this the “TV nature special” world view, where everything is perfectly adapted and completely interconnected and dependent on everything else. And despite the fact nature specials now show predation (didn’t much when I was a kid) they still have a Panglossian every thing is good overtone.
@Brian:
“And despite the fact nature specials now show predation (didn’t much when I was a kid)”
Hmm. I’m pretty sure I recall nature documentaries about great white sharks and lions from back when I was a kid, but perhaps not? And surely stuff like male bighorn sheep fighting over access to females is sufficiently visually impressive that it’s long shown up in nature documentaries?
In any case, your comment raises an interesting question: what are the best nature documentary treatments of natural selection? Are there any that don’t just talk about it at length and get it right, but that explicitly take on widespread misconceptions promoted (or at least not refuted) by the bulk of nature documentaries? Alan Alda once did one on Darwin and the Galapagos for PBS that was quite good on natural selection. It’s from 1998 or so.
Although one might assert the topic of mutualism is a bugaboo unto itself. Commensialism, for example… does it really exist? Symbiosis???
Seems as time goes on, more and more of these presumed mutualisms really turn out to be more parasitic than anything else… at least once we grasp the totality of the relationship. So I think part of what you mention concerning the TV worldview is absolutely correct. But I also believe ecology puts forth some of this “Vulcanesque” worldview (“The good of the many outweighs the good of the few”) with what could be characterized as Garden of Eden hypotheses.
I would prefer, for example, that the mutualist camp begin all investigations with the presumption of parasitism/ predation…. rather than the reverse, because then the layers of the onion must be teased apart to unseat the folly of all of this. So for example- the ant-aphid-buchnera trio appears to be a classic example of mutualism. But is it really? The ant hijacks the sweet sugars collected by the aphid in exchange for “presumed” protection, and the aphid & buchnera are likely just exploiting one another. Yet, we couch these things as Garden of Eden idyllic relation ships.
Chances are, they are all simply clinging to survival.
@DSS
“Although one might assert the topic of mutualism is a bugaboo unto itself…..we couch these things as Garden of Eden idyllic relation ships”
As someone who’s done a lot of research on mutualisitic interactions, I’m going to push back on this one. I know of no serious mutualism researchers who would discuss their systems in the way that you describe and I think you’re mixing up populist views of nature with the real science that’s being done.
Clearly all mutualism is mutual exploitation. But the difference in these systems is the fitness outcome for that exploitation: in parasitism/predation there’s a loss of fitness in one of the partners, whereas in mutualism there is a fitness gain (or at least no loss – which may be our definition of commensalism).
Group selection (which is very Gaia) has long been invoked to explain male-male competition. They’re picking the best males to mate, for the good of the species. So, yeah, they’ve long shown bighorns colliding, but that didn’t bother anybody because it wasn’t selfish.
After studying animals in the field, I find it hard to watch nature shows now, since it’s become so easy to see how cobbled together the footage is, often to make points that have nothing to do with what’s actually going on in the film… so I can’t comment about which shows best talk about natural selection.
“Group selection (which is very Gaia)”
Depends what version of “group selection” you mean. Woolly “good of the species” thinking, absolutely. The very non-woolly sort of thing that’s it’s own subfield of modern evolutionary biology, not so much. Indeed, that stuff is quite non-Gaia, since basically what it says is that individuals within groups all need to have their interests aligned and work together towards the same ends so that they can outcompete other groups.
Growth curves… and the associated log transformation.
You mean, notions like Gompertz or von Bertalanffy growth? People who work on life history evolution definitely haven’t discarded those (well, various growth curve models have been proposed, perhaps some have been discarded). Or do you mean some other sort of growth curve?
I think the highly idealized growth curves… and perhaps it would be better stated as “curve fitting”. Also the implicit concepts associated with them- “carrying capacities” “ultimate balance” “equilibria”.
Certainly these ideas hang on, but I think most acknowledge the chaotic behavior of natural systems precludes any long term realization.
@DSS:
Whether ecologists have rejected concepts like carrying capacity and equilibrium depends what you mean by “rejected”. Nobody expects any natural system to literally exhibit logistic growth or whatever, though I don’t know that anybody ever did. And perhaps we’re more conscious of possibilities like chaos than we once were. But concepts like carrying capacity and equilibrium remain quite useful (and often used) conceptually, and there are plenty of real-world cases in which they apply approximately if not exactly. Think for instance of the Park Grass experiment, which has been at a quasi-equilibrium for a long time now.
How about the Odums’ idea that ecosystems develop over the course of succession so as to maximize various variables? Though I’m not sure if ecologists have totally given up on those ideas–I think maybe Ulanowicz is still pushing a version of that idea? (Not sure, ecosystem ecology isn’t my field…)
If we broaden it to evolutionary biology, there’s naive “good of the species” thinking. And probably inheritance of acquired characters, though people who think maternal effects, DNA methylation, etc. are really important are trying to keep that idea alive. Don’t think macroevolutionary types have quite given up on punctuated equilibrium, but I’m not sure.
Having recently published a paper with “island biogeography” in the title (and obviously in the body as well), some folks ask, “but isn’t island biogeography dead?”. Others assert we should have used metacommunity ecology.
I think it’s true that metacommunity ecology has largely supplanted the use of island biogeography, but this is a different issue, isn’t it? That an old, popular theory has been replaced by a newer, more comprehensive one doesn’t mean the old theory has been rejected. On the contrary, most would probably argue that island biogeography has been largely accepted, but subsumed into metacommunity ecology. By analogy, island biogeography is like the genius tech start-up that got bought out by Google (or Hooli) for 10 million dollars.
If there are few cases of properly rejected ecological theories that were once giants, how many cases of intellectual buyouts are there?
Yes, saying an idea is “dead” in the sense of “nobody works on that anymore” or “it’s been supplanted by a different idea” is different than saying an idea’s been rejected because it was just wrong (and otherwise unhelpful). As a non-ecological example, Newton’s laws of motion aren’t the subject of active research anymore as far as I know, and they were supplanted by relativity. But they weren’t rejected–they’re actually an excellent approximation to relativity under many conditions and still are used to plan space launches.
not a point of disagreement, but those space launches explode!
Not because of Newton’s laws. Presumably. 🙂
Minor point relative to the topic, but there is an ever growing line of thought that relativity did not supplant Newtonian physics… but completed it. Still others suggest they are one in the same.
You mention succession here at one point and I agree in so much as we need to heavily modify our idea of succession. One we ought give up on is the idea of the climax community–at least in there being an ultimate endpoint/trajectory for any ecosystem. I feel it is a bankrupt term that too often surfaces in the literature. Great post by the way.
Yeah, “climax community” might be a candidate for the list. Although to the extent the term is still used in the literature, it’s a zombie idea rather than an idea ecologists have rejected.
WRT “I predict that at least one comment will be from someone arguing that … broken stick models aren’t dead”, I’ll be happy to provide this. They should be dead. They’re a terrible fit. And their inventor argued over 50 years ago that they should be dead. But there are still papers fitting broken stick as one of a handful of SAD models every year. And a lot of textbooks still have pictures explaining broken stick.
Overall, I’m not going to be the person to suggest ecology has successfully killed off ideas. Although I do have to give you superorganism as a pretty good try.
Maybe estimating lotka volterra competition coefficients from niche overlap?
But there aren’t many out there.
“Maybe estimating lotka volterra competition coefficients from niche overlap?”
Nobody does that explicitly anymore. (Though I wouldn’t be at all surprised if somebody tried to revive it, in the mistaken belief that it’ll work now because we have more data or can fit hierarchical models or something.) But *implicitly*, people still do this all the time.
“But there are still papers fitting broken stick as one of a handful of SAD models every year. ”
Perhaps “death” is a matter of degree. Surely there aren’t *that* many people still doing this? And the people who are mostly aren’t publishing in leading journals, are they?
And since I’ve just given myself an opening to link to this, I’ll take it:
🙂
Often, species distributions do not conform to any of the available selections, or they obey several. In this sense having the broken stick around as a means of reference to convey a pattern is probably useful, although its predictive capabilities are not worth a plugged nickle.
Is “taboo labels” the same or different. For example, it is a kiss of death to a paper to talk about r-K selection yet we keep reinventing it as “fast-slow life history continuum” and “leaf economic spectrum”.
I don’t think an idea counts as rejected if it just gets revived under a different name. Which gets into different but related issues, of how to tell when a “new” idea is truly new vs. old wine in a new bottle.
And yet r-K selection remains in most introductory ecology text books as well. For that matter so is the climax community, L-V competition coefficients, and sometimes even (at least in passing), the superorganism and even the Gaia hypothesis. Now the last two are usually “honored in the breach,” i.e., mentioned only to be jettisoned, but part of the persistence of these ideas might be widespread early exposure. We know they are inadequate, yet we keep them in the textbooks. Why?
This leads to the broader question touched on above about what it means for an idea to be “permanently rejected.” Just as Newton’s Laws have been surpassed yet remain quite useful, maybe ecologists keep ideas around even though we know they are in some sense scientifically insufficient, simply because they are useful for particular purposes. As Jeremy mentioned above, even though ecologists have largely rejected the traditional, purely equilibrial “balance of nature” perspective, we still find many cases in which it is quite useful to apply the concept of carrying capacity or equilibrium.
Perhaps ideas in science are less like toys or tools, static artifacts to be used in a particular way or discarded, and more like clay or legos, materials that can be continually reshaped and modified. Should we expect any ideas of real impact to be wholly discarded from our scientific toolbox?
Just to be clear, I (and I believe Brian) are fine with the notion of competition coefficients. Indeed, I’d like to have more good estimates of them! The rejected idea here is a seriously-flawed-but-once-popular way of estimating them.
“Should we expect any ideas of real impact to be wholly discarded from our scientific toolbox?”
Yes, if you think that ideas never become important/influential/etc. unless they have some important grain of truth or are useful in some other way, then yeah, you wouldn’t expect or want any important/influential/etc. idea to ever get totally, permanently rejected. But as you note, the premise is false–ideas do sometimes become important/influential/etc. despite having no grain of truth and no other redeeming features. Clementsian superorganisms, for instance–the world just isn’t like that, and there’s no purpose for which it’s useful to think of the world as being like that. Or think of various zombie ideas, that should be dead, but aren’t. Like the idea that disturbances promote coexistence by “interrupting” competitive exclusion. That’s just wrong. It’s in the textbooks not because it contains a grain of truth, or because it’s sometimes useful to pretend that it’s true, but because it’s an intuitively appealing mistake.
I’m not sure I am fine with competition coefficients. In 80 years we’ve never found a way to estimate them that isn’t a circular, phenomenological curve fitting. This makes lotka volterra competition pretty useless for any precise predictions. They now function only in a vague qualitative/strategic model/list possible outcomes way.
But we agree that niche overlap is a deservedly dead approach.
For Drew’s analogy, I don’t think Newton’s 3 laws of motion have been rejected so much as shown to be approximations that are closer approximations (indeed extremely close approximations) at earth-sized scales than cosmological scales.
That’s pretty different than some ideas that have been outright rejected in physics like ether.
“In 80 years we’ve never found a way to estimate them that isn’t a circular, phenomenological curve fitting.”
Hmm…well, competition coefficients *are* phenomenological, in the sense that there could be lots of mechanistic reasons why the per-capita growth rate of species X would decline with increasing density of species Y, all else being equal. They’re no different than the notion of “density dependence” in that way (or “natural selection, for that matter–phenotype-fitness covariances are phenomenological statistical associations that can arise for all sorts of mechanistic reasons…). But why would that mean that any estimate of competition coefficients is “circular”? You kind of lost me–are you sure “circular” is the word you want? “Curve fitting”, I get–I’ve estimated competition coefficients that way from time series data, as have many other folks of course. Although even there, you certainly can use curve-fitted competition coefficients to make precise testable predictions. Again, I know because I’ve done it myself (Fox 2007 Am Nat–that the predictions were wrong doesn’t undermine my point, I don’t think.) Is it that you want a model that predicts what the competition coefficients ought to be?
If the only way you can estimate coefficients is to fit them to the timeseries which they then predict there is a circularity. I’ve not seen them used too often to predict something other than the same timeseries they were fit to (occasionally a later part of the timeseries or a different replicate but not even those too often). Anyway, not going to draw a line in the sand over circularity, but to me the usage often seems circular.
I would either like to see the coefficients estimated independently of the timeseries (your model to predict coefficients), or the coefficients used to make predictions other than the timeseries. Turning the quantitative timeseries into a qualitative prediction (e.g. extinction) does’t count. Have to confess I haven’t read your 2007 paper so can’t comment on that.
“I’ve not seen them used too often to predict something other than the same timeseries they were fit to (occasionally a later part of the timeseries or a different replicate but not even those too often).”
Ah, ok, I’m with you now. Go read Fox 2007 Am Nat; I’ll wait here. 🙂
The Ecological Footprint? It seems as though this is a dying concept… not yet dead, but probably should be removed from life support.
I always found it a fool’s errand anyway. Not really all that informative, because it actually does not measure impact, but only perceived impact.
I think we need to be much more process oriented, to examine things not only in terms of consumption, but rather how goods are produced, utilized, conserved, reused, recycled, etc.
Inflow, outflow, and so on.
“The Ecological Footprint?”
I wouldn’t really know. That’s an environmentalism notion. Whether you count it as an ecological concept depends on how broadly you define “ecology”.
Agreed, very environmentalist in nature, yet I have seen it presented in many ecology/ biology courses. I suppose attaching the term “ecology” doesn’t make it ecological per se, but laymen believe it to be. And in the models I have played with they integrate a good bit of ecological data.
@Brian from earlier in the thread:
“But we agree that niche overlap is a deservedly dead approach.”
Here’s a brand spankin’ new paper that doesn’t go so far as to quantitatively estimate competition coefficients, but certainly does make inferences about strength of competition and coexistence just from diet overlap data:
http://www.pnas.org/content/112/26/8019.abstract
I am a bit confused here, would be great if you could quickly clarify this point for me. Thanks.
“But we agree that niche overlap is a deservedly dead approach.”
Do mean that niche overlap is a dead approach to estimate competition coefficents or that niche overlap per se is a dead approach?
We’re referring to the former. Not sure what you mean by the latter. But if you can’t use niche overlap to infer something about competition, it’s not clear why you’d care about it. I don’t think niche overlap is intrinsically interesting in its own right.
Diversity begets instability (of the whole system).
Whether that’s an idea we’ve decisively rejected depends on one’s definition of “stability”, I think.
Dependent upon what “stability” is. Same as deceased entropy?
“Same as deceased entropy?”
No. At least, that’s a rarely-used definition in ecology. I believe Margaret is thinking of definitions to do with reduced temporal variability. And in my reply, I’m thinking of definitions to do with the return rate of a system to equilibrium or some other attractor, or perhaps the probability that the system will have a feasible attractor.
I would concur about the definition issue. Also I would point out a need to better ferret out the element of diversity acting in relation to instability… which in my work, was far from easy. I defined “instability” in terms of “community decoupling” as it pertained to an array of community types (some might argue guilds, although I am not as certain of that). Community structure was assessed as the tendency of ecologically-relevant communities to form sinusiae (become stratified) within riparian corridors.
Curiously, instability presented itself in a variety of formats. Bio-invasion indeed exploded as decoupling progressed. However biodiversity did not appear to change as a function of percent cover of invasive species, but it did change (decreased) when invasive species formed sinusia.
The formation of sinusiae was considered a more ordered state compared to habitats where they did not form, or there were fewer of them. Thus, the emergence of uniform bands of exotic species parallel to channel banks was considered an increase in order (opposed to disorder,) while biodiversity concurrently decreased in comparison to habitats where exotics were not stratified. At first glance that would seem to represent disorder (a system moving away from equilibrium). However it was the range/ variance of diversity that was correlated with increases in the formation of sinusiae, not the mean. The range was curtailed from both tails of the distribution of diversity while the mean remained constant in regard to overall stratification of communities. That effect was therefore also judged to represent increased stability (i.e., increased order).
I used that information to construct an equation for ecologic integrity (The Vegetative Complex Health Index), using biodiversity as a scalar, and community structure and bio-invasion as the mean aggregate. The nuancing came into play because the scalar caused habitats with stratified invasive species to drop out of those VCHI ranks considered good & excellent due to the negative correlation with biodiversity.
So I suppose in this case one man’s stability is another man’s instability… .
Hi Jeremy, what about habitat fragmentation as important for population persistence? Early landscape ecology used the terms loss and fragmentation almost interchangeably but once they were tweezered apart there was a conviction that where and how many pieces of a constant amount of habitat, mattered. Now, I would say that most landscape ecologists are convinced that where and how many pieces is almost always way less important than how much. And when fragmentation matters, increased fragmentation is often better than decreased fragmentation (in terms of population persistence). I guess this is connected to the SLOSS debate, which I think has disappeared because the answer is seen as completely context dependent and so the debate as unproductive.
This has been an eye-opener for me because my discontent with progress in ecology stems from the fact that there are so few things I am certain are true (and I think that’s more or less true for most ecologists…not necessarily that they are unhappy with ecology but that there are few things they can be certain are true). This conversation is illustrating how few things there are that we are certain are false. It seems to me that the success of a discipline is pretty much captured by (The things we know are true + The things we know are false). This sum in ecology strikes me as relatively small. That may be because what we are certain is true or false depends on where and when you do your research but in ecology we haven’t even figured out at what spatial and temporal scales we can make general statements.
Jeff H
I was about to say “deterministic chaos”, but then a new paper suggest it might not be so dead… http://www.pnas.org/content/112/20/6389.short However, it seems fair to say that the original idea that (deterministic) chaotic population dynamics might be everywhere has been rejected. Of course, some lab systems can be designed to be chaotic, and some community modules in the wild can be “at the edge of chaos” or in stochastically/seasonally-driven chaos etc., but the idea that a likely explanation for erratic fluctuations in the wild is a logistic-map type of chaos seems to have been rejected. (the accompagnying commentary piece to the Benincà paper in PNAS, by Bjørnstad, is pretty good on telling the story http://www.pnas.org/content/112/20/6252.extract)
I’ll buy that, except that it’s not clear to me how “likely” deterministic chaos was ever considered to be.
I’ve always thought the issue with supporting or refuting this idea rests upon the scale of the data we have to assess it. In all likelihood, if such a process exists, then it seems reasonable it would be rooted in biogeochemical cycles… a broad framework I confess. However these cycles are the subject of geologic temporal scales. While we have some data at this scale (ice cores, fossils, sediments)- there just isn’t enough to provide any rigorous test of the theory.
I know there has been some discussion of the Gaia Hypothesis in this string of comments. Admittedly I have not kept pace with the literature on the topic, but it seems there has been a resurgence of sorts in terms of support for some of its elements, while the overall theory has pretty much been discarded.
To that end I am curious about the status of the Medea Hypothesis, and related Cronus Hypothesis. Apparently the Cronus worldview melds the Gaia and Medea hypotheses into some sort of unified view. Is there any substance to this approach, which claims to be deeply rooted in mathematics, or is it just another idea destined for the scrapheap?
‘Balance in Nature’ ‘equilibrium in Nature’ are broader worldview on nature and how nature works. aren’t these views already rejected?
Quite likely they have been broadly rejected, however, an equilibrium state is not necessarily a balanced state. I believe that is an important distinction because it enables the elucidation of equilibria without the expectation of balance, and v.v..
Balance implies equal distribution- for example- by placing two, 5 gram blocks on each side of a scale. Extending this to ecology, one could say a community was “balanced” if all species occurred in equivalent numbers (same relative abundance). However that community may or may not exist in an equilibrium… defined by its preservation across a temporal scale.
Obviously we very often observe log normal species distributions, where just a few are dominant and the rest relatively rare. Furthermore, we see that log normal distribution very often preserved across broad temporal scales. It is unbalanced, however I would argue its persistence represents equilibrium relative to the physiographic features of the environment.
Regime shifts have received attention lately, regarding the lack of evidence (or direct link between changes in ecological processes and real shifts) and liberal use of the term in aquatic ecology.
Now, I don’t know if empirical evidence of regime shifts have been permanently rejected or criticized by ecologists, since I’m not 85 years old and just a master candidate, but I think it’s a good ground for discussion.
Capon et al. (2015) recently discussed this topic in that paper (URL below). It’s worth a reading.
http://www.sciencedirect.com/science/article/pii/S0048969715001886
BTW, thanks for this blog, it’s refreshing to have a place to discuss these interesting subjects, and confronts ideas instead of methods and statistical analyzes.
I agree with you that “regime shifts” (and “alternate states”) is one of those terms that often gets tossed around without good evidence.
Glad you like the blog (though we host our share of statistical/methodological discussions too if you ever want that…)
The Gaia hypothesis you regard as rejected seems to be like the group selection hypothesis that is rejected (a dated concept with a modernised successor). Searching Scholar for “Daisyworld” instead, enough publications for 2014 come up to consider it not dead.
Elements of the Gaia theory have recently experienced a rebirth. James Kirchner (Berkeley) is likely the person who lead the charge in opposition to Lovelock’s idea, asserting time & again it was an ambiguous and untestable hypothesis. Kirchner’s views on Gaia are rooted in the reductionist philosophy of Karl Popper. However it now seems likely ecological modeling could test aspects of Gaia.
The hypothesis is rooted in the idea that the interaction between biota and the atmosphere give rise to a homeostatic mechanism sustaining life. Likely the best evidence Lovelock presented on this mechanism concerned nitrogenous/ sulfuric gases in the atmosphere relative to the two static states of the planet: glaciated v. warm. The correlation observed from ice cores was nearly perfect concerning the transitional state. Obviously correlations do not necessarily translate to causations.
In 1979 Lovelock himself declared Gaia an untestable hypothesis. In 1983, he began to reverse course with the publication of Daisyworld, arguing Gaia was neither deterministic nor teleologic. In he 1988 came full circle with Ages of Gaia (an excellent read, BTW). In 1991, Lovelock wrote: “… I am well aware that the term itself (Gaia) is metaphorical and that the Earth is not alive in the same way as you or me, or even as a bacterium. At the same time I insist that Gaia theory itself is proper science and no mere metaphor.”
A growing number of scientists now maintain aspects of Gaia can be tested as a chaotic system using holistic ecologic models. So you are correct, Gaia is not dead, and it is likely to experience increasing attention on the literature.
An idea that’s alive in one field or subfield can be dead in another. Were any of those papers in mainstream ecology journals?
By no means a whose who of journals, and by no means a cascade of recengt activity. But there does seem to be some momentum developing concerning empirical means to test Gaia. Oduroa et al. 2012 probably holds the most promise at this time.
Clarke B (2009) Neocybernetics of Gaia. In: Crist E, Rinker HK (eds)
The emergence of second-order Gaia theory, Gaia in turmoil.
MIT Press, USA
Free A & Barton NH 2007. Do evolution and ecology need the Gaia hypothesis? Trends in Ecology & Evolution 22(11) 611-619
Karnani, M. and Annila, A. (2009). “Gaia Again”. Biosystems 95 (1): 82–87
Kleidon A 2004. Beyond Gaia: Thermodynamics of Life and Earth System Functioning. Climate Change 66(3) 271-319
Kleidon A. 2009. Nonequilibrium thermodynamics and maximum entropy production in the Earth system. Naturwissenschaften 96(6) 1-25
Kump LR (2009) A second opinion for our planet. Science
325:539–540
Lenton TM (2002) Testing Gaia: the effect of life on Earth’s
habitability and regulation. Clim Change 52:409–422
Lenton TM, Wilkinson DM (2003) Developing the Gaia theory. Clim
Change 58:1–12
Lenton TM (2014) A Philosophical Look at Gaia. BioScience Volume 64, Issue 5 Pp. 455-456.
Luisi PL (2003) Autopoiesis: a review and a reappraisal in:
naturwissenschaften. Springer 90(2):49–59
Oduroa H, Van Alstyneb KL, and James Farquhara J 2012. Sulfur isotope variability of oceanic DMSP generation and its contributions to marine biogenic sulfur emissions. PNAS 109(23)
Scannerini S (2003) Il paradigma di gaia.
http://www.intelligenzartificiale.com/paradigma_gaia.htm
Schneider SH (2001) A goddess of Earth or the imagination of man?
Science 291:1906–1907
Scientists Debate Gaia: The Next Century. Stephen H. Schneider, James R. Miller, Eileen Crist, and Penelope J. Boston, eds. MIT Press, Cambridge, MA, 2004. 377 pp
Scofield, B. (2004) “Gaia: the living Earth—25,000 years of precedents in natural science and philosophy.” In S. H. Schneider, J. R. Miller, E. Crist, & P. J. Boston (Eds.), Scientists debate Gaia: The next century (pp. 151-160). Cambridge, MA: MIT Press
Vedral V (2011) Living in a quantum World. Scientific American
Volk T (2004) Gaia is life in a wasteworld of by-products. In:
Schneider SH, et al. (ed) Scientists Debate Gaia. MIT Press,
USA, pp 27–36
I have “The Ages of Gaia” and always thought that was the Gaia hypothesis, a negative feedback on a global scale that _tends_ to keep the temperature of the planet within a habitable range (though not by all means and not for all time and not against all human actions). If that’s not the Gaia hypothesis being rejected by everybody, I wonder what silly caricature is? Lovelock cannot really have meant an Earth as Superorganism theory? Can he?
By the way, David, you forgot Lenton’s paper in Nature or is that too old?
As 2001 is not too old for you, then you should have mentioned Lenton’s paper in Philosophical Transactions B (2002), or his Journal of Theoretical Biology paper (2000)?
My apologies if I gave the impression I was providing a comprehensive list. I was only trying to indicate the idea persists, and recently some have suggested there are empirical approaches for testing it. I’m sure there were many papers I missed, but no slight was intended.
Well okay, just read a review by Kirchner. If it is true that the Gaia proponents are biased to think that global feedbacks are generally negative and life-enhancing, and neglect the possibility of positive (destabilizing feedbacks), then that’s a good reason for rejection.
On the premise that ecology must have it’s phlogiston in order to be a proper science, I think, superorganism metaphors are good candidates anyway–except, maybe, the entomological one of a state of social insects.
I know there is quite a bit of confusion of what Lovelock intended when he proposed the Gaia Hypothesis, & the related theory. Lovelock is likely responsible for a good bit of the mystification of Gaia, given his flip-flopping. My view is, were he to have it to do all over again, he would have begun with much smaller steps, and would have avoided terms like “Gaia” (teleologic inferences) and “Superorganism” (Godzilla and such). He also made unfortunate analogies throughout his arguments, especially concerning organisms, populations & communities. These missteps have given rise to cult-like belief systems that really have no place in science. Not to say they do not have a place, but the mixing & mingling of science with theology is a risky business at best.
Rachel Carson created a similar mess when she published Silent Spring. Intentional omissions of relevant data along with some glaring misinterpretations of data created a mysticism that has no basis in reality, and dogs science to this day. Although I give Lovelock more of a break, because as an atmospheric science, his understanding of biological systems was far from complete.
I would have preferred much more emphasis in terms of the physics, and how the interaction between biota, inorganic processes and climate gave rise to a sustainable atmosphere. That is essentially the nuts & bolts of Gaia, but Lovelock’s tendency to become grandiose in his arguments created a monster on par with the Carson crappola. In both cases, they encouraged the integration of environmentalism with science, although Lovelock has stated repeatedly this was not his intent.
Kirchner himself did not attack the idea of Gaia, but the very flawed manner in which Lovelock presented it (see below). So I would argue the idea is not dead, but unfortunately, neither is all the hullabaloo surrounding it.
“Particularly because I have been a vocal critic of the Gaia hypothesis, it is important to make clear that I substantially agree with many of its central themes. I agree with Gaia, in the sense that I think that no view of the Earth system can be complete– or even approximately correct – without accounting for the pervasive influence of biological processes on Earth’s surface chemistry and climate. I agree that coupling between the atmosphere and biosphere should naturally give rise to feedback. I also agree that coupled feedback systems can exhibit ‘emergent’ behaviors, including self-regulation. And most importantly, I agree that it is essential to understand the Earth system as a system, rather than as a set of disconnected components.” – Kirchner 2003.