Thursday, June 25, 2020

Is Gaia a Superorganism? No, she is a holobiont!

A few days ago, I was discussing with a friend and he used the term "superorganism" for Gaia as the Earth Goddess. When I said that Gaia is not a superorganism but a holobiont, he asked me, "but what is a holobiont, exactly?" I thought about that for a while, and then I said, "a holobiont is a democracy, a superorganism is a dictatorship."

If you have a friend who is a biologist, try to tell her that Gaia is a superorganism. Likely, she won't be happy and she might ask you, rather venomously, "And so, tell me, good sir, how could natural selection have generated this -- ahem-- 'Gaia' of yours? You tell me that there is only one Gaia on this planet and so, in order to evolve, did perhaps different planetary ecosystems in the galaxy competed with each other?" I am not inventing this, it is the scathing criticism of the Gaia theory that Richard Dawkins produced in his book, "The Extended Phenotype" (1982).

Given a certain interpretation of Darwin's idea, Dawkins' position is logical and even unavoidable. There is just one problem: the common interpretation of Darwin's theory is wrong.

Don't misunderstand me: Darwin was one of the greatest scientific geniuses in history. But we need to take into account that he was working on limited data and with limited tools. He himself could never decide exactly between two concepts that he used interchangeably: "natural selection" and "survival of the fittest." They are not the same thing, not exactly at least. If you emphasize the idea of the "survival of the fittest," then you see evolution as a continuous competition among the best in the search for the even better. It is a cutthroat competition, nature in red tooth and claw.

But it doesn't have to work that way. An alternative view of evolution is more compatible with the idea of "natural selection" and it takes its inspiration mainly from the work of Lynn Margulis (1938 - 2011). In brief, the unit of evolution is not the organism (at least, not only the organism) but the holobiont. And evolution is not competitive but mainly collaborative. 

It is a long story, and I invite you to read the fundamental book "Symbiotic Planet" (Margulis, 1998). See also an article of mine on "Cassandra's Legacy" and my Facebook group on holobionts. To summarize, holobionts are collaborative societies of organisms that live together, helping each other. A good example is a human being, a community formed of the main organism (the proper "human"), and a large number and variety of micro-organisms (the microbiota) that live inside and on the surface of the main organism. Every living being on this planet is a holobiont, and there are holobionts formed of smaller holobionts: think of a forest. Trees are holobionts, a forest is a holobiont formed of trees. Holobionts are a self-similar entity operating at various scales.

Then, evolution is a mechanism for keeping a population stable. It operates mainly at the bottom, not at the top. Those organisms which are defective because their genome is damaged, those that Gorshov and Makarieva call "decay individuals" (Biotic Regulation and the Environment, 2000), are removed and the genetic information contained in the population is maintained intact in order to regulate the system. It is not the "survival of the fittest" but the "non-survival of the unfit."  It is a mechanism that sheds entropy away from the system.

Holobionts do compete, but the concept seems to be (this is an interpretation of mine) that while organisms search for perfection, holobionts strive for the good enough. Mostly, holobionts just survive. And those that survive tend to shed away those parts of themselves which are not good for survival. Holobionts continuously exchange genetic information with other holobionts (it is called "holosex"). In this way, they teach survival techniques to each other. You could say that holobionts are a democracy, while organisms are a dictatorship. (you might also say that holobionts are communists, but that means pushing the similitude a little too much.)

So, back to Gaia, now it should be clear that Gaia is a holobiont, just like us (see also this article by Castell et al.) You could call Her a super-holobiont that includes all the smaller holobionts of the biosphere. Then, this idea overcomes Dawkins' objection: Gaia exists not because She competes with other superorganisms. She exists because the sub-holobionts that form Her collaborate with each other. Think of a forest: did it evolve by competing with other forests? No. It came to exist because trees survive better together than alone. The same is true for Gaia. She operates like all other holobionts. She survives because the living beings of this planet survive better (actually, only) if they are together. Gaia is what She is.

The beauty of this concept is that it gives a form and a substance to Gaia that other views don't provide. So far, Gaia has been an abstract term, mostly described in terms of scientific models and equations. But if She is a holobiont, well, the Goddess is one of us! She is a living being just like us. And when you pat, touch, or caress another human being, you are patting, touching, and caressing the Goddess herself. You can do that with your dog, too! We, living creatures of the biosphere, all partake in the same holobionticity!

And so things stand: onward, fellow holobionts!

See my also facebook group on holobionts  and Erik Assadourian's site on Gaianism

Note: these ideas are not new, after all: 

I will sing of well-founded Earth, mother of all, eldest of all beings. She feeds all creatures that are in the world, all that go upon the goodly land, and all that are in the paths of the seas, and all that fly: all these are fed of her store. Through you, O queen, men are blessed in their children and blessed in their harvests, and to you it belongs to give means of life to mortal men and to take it away.” Homeric Hymns,


  1. I wish this would be taught in all schools, along with a reverence for nature.

  2. Likewise, we are composed of collaborating cells, they are composed of collaborating components too.
    Holobionts, all the way down! (And all the way up?)

  3. Within the Gaia holobiont, a superparasite evolved that destroys the host. Superparasite is not the part of the holobiont. It has it's own motivations and goals that are not in any way connected with the holobiont. The special characteristic that superparasite has is the "sapiens" part of the parasite's name. Only "blessed" with this characteristic, superparasite can explot the host in destructive way. Superparasite's purpose is not to cooperate but to destroy until there is no more food to satisfy it's voracious appetite. It's easy to see what program the parasite's mind is operating on. Look at how parasites are behaving among themselves. Superparasite is species with dangerous mutation. Sometimes mistakes happen. Good news is that all species have expiration date.

    1. It happens. Holobionts are dynamic, they change all the time. Eventually, they find stability, but there may be occasional wild oscillations. It is happening. It will end, but not without some damage -- maybe a lot of damage, but Gaia is very resilient

  4. Holobiont is full of parasites. Homo sapiens is not the only one. If the purpose of holobiont is mutual cooperation between species, then why there is parasites? Parasites live by destroying hosts. All pathogenic multicellular organisms, bacteria and viruses are here with sole purpose of destroying particular host by using it as food until there is no more food. Therefore, it's questionable that there is some cooperative effort within holobiont. Rather, it's the random statistical equilibrium (or distribution) that is prone to some disturbances.

    1. Parasites evolve to live with their hosts. Diseases become less deadly over time because otherwise they die out with their hosts. Some human parasitic worms are beneficial as they moderate the human immune system preventing overreaction.
      A classic example of cooperative effort is the Bluebottle jellyfish that is a colony of different animals. We ourselves rely on the bacteria in our gut to digest our food and kill pathogens. The bacteria on our skin protect us. Trees are helped by fungi in the soil that make food available to their roots. All life is interdependent and intertwined.

    2. According to the theory of biotic regulation -- the book by Gorshkov and Makarieva I cited, the "normal" condition of the biotic system (they don't use the term "holobiont") is that of tight control and stability. They say that waves of parasites exist only in strongly perturbed and decayed systems. Which is certainly the current situation. I don't know if this idea can be considered as proven, but it surely makes a lot of sense

    3. The biotic system must be very resilient to have recovered from each mass extinction. Perhaps the microbiome provides an underlying stable base.

    4. Humans are superparasites because they exploit every ecological niche. The purpose of huge brain is to enable adaptation to every ecological niche and exploit it. No other parasite has that ability. That's why superparasite is so dangerous, especially western form of the parasite which is particularly virulent and aggressive.

      In the case of gut bacteria, that's symbiosis, not parasitic relation. When there is mutual benefit, that's symbiosis. There is no mutual benefit if yersinia pestis or ebola virus invades your blood. Only parasite has benefit. You die.

  5. In arguing against the Gaian concept, I think Dawkins quibbled, overlooking his own principle of 'the extended phenotype'.

    He essentially argued for causal chains of influence from genes, via their phenotypic expression in individuals, to those individuals' shaping of their environment. The environment, he argues, is in large part shaped by the genes. Its character and dynamics are therefore plausibly subject to natural selection with feedback (he uses a beaver pond environment as one example).

    His argument that Gaia cannot have evolved, I think, incorrectly equates 'evolve' with 'evolved' and ignores his thesis. For example, he considers genes to be the unit of selection... they 'evolve'. Yet bodies built by genes are nevertheless 'evolved'. The terms 'organism' and 'super-organism' don't of themselves specify which pertains. 'Holobiont' is certainly more expressive and accurate for this discussion.

    He could (should have?) easily and without issue have approved of Gaia as 'the sum of all extended phenotypic effects' (aka the 'biosphere') and therefore as much evolved as any body built by genes.

    In general, I'd love to see the useful concept of the extended phenotype fully integrated with the Gaia Hypothesis.

    And wasn't Lynn Margulis something! 8)

  6. Facebook is a closed book to those who (like me) don't do facebook, on the sage advice of Mark Zuckerberg.



Ugo Bardi is a member of the Club of Rome, faculty member of the University of Florence, and the author of "Extracted" (Chelsea Green 2014), "The Seneca Effect" (Springer 2017), and Before the Collapse (Springer 2019)