Feathered Dinosaurs -- The Many Faces of Gaia

 

A feathered T-Rex? Why not? (Image from Safari Ltd.)

A recent paper by Olsen et al. appeared on "Science Advances". It discussed the fauna and the climate of the Earth of Late Triassic, just before and during one more of the great mass extinctions of its long history.

The authors claim that "The Late Triassic and earliest Jurassic are characterized as one of the very few times in Earth history in which there is no evidence of polar glacial ice sheets," which I am not so sure about. Anyway, this Late Triassic Iceless age is interesting for us because it is where we may end as the result of the current burst of fossil carbon combustion, deforestation, and marine desertification. It is another example of ice-free earth, probably similar to the Eocene epoch, some 30-50 million years ago.

It seems that the Late Triassic was not so hot, despite the high CO2 concentrations (maybe 1000-6000 ppm). In the high latitude regions, the temperature was cold enough that ice would form in winter, likely not perennial. Dinosaurs lived in the Northern and Southern areas of the Pangea, and they already had "filamentous integumentary cover" -- beautiful term! -- that is protofeathers, clearly used for thermal insulation. In the equatorial regions, instead, the heat made life easier for cold-blooded animals, the pseudosuchia -- which indicates crocodile-like creatures. Apparently, it was too hot for dinosaurs there.

Does this have some relevance to the current climate? Everything is correlated, although it must be said that the conditions of the earth some 200 million years ago were quite different. The fact that there was ice at the poles, despite a very high CO2 concentration, is no proof that CO2 is not the greenhouse gas we know it is. Among many other things, the solar insulation at that time probably around 2% lower than it is today.

Today, if we were to go back to those CO2 concentrations, crocodiles may still have a good time, but they will probably invade a much larger share of latitude. On this point, this is a paleontological study, so they don't mention modeling the climate of those times. They tend to attribute the low temperature to volcanic ashes. They seem to say that the mass extinction was caused by cooling, unlike the later K-Pg event. That despite the fact that the CO2 concentration was so high. Their main conclusion is that dinosaurs were adapted to cold temperatures, and they were mostly feathered. Which means that the creatures seen in "Jurassic Park" are all wrong!

They also report this interesting graph with the CO2 concentrations over 300 million years. It is stuffed with acronyms, apparently well known by paleontologists, but not so much by us, mortals. Anyway, "EPE" stands for "End Permian Extinction" (the huge one)   "ETE" stands for "End Triassic Extinction" (less well-known, but it was not a joke). "T-OAE" stands for "Torcian Oceanic Anoxic Event" (quite an event, it must have been). The "K-Pg-E" is an acronym of acronyms, but you know what it stands for: it is the end of the dinosaur age -- the big asteroid falling on Earth (maybe) or/and the Deccan giant igneous province (more likely). Finally, the PETM is the "Paleocene-Eocene Thermal Maximum", quite a maximum in temperatures, but it didn't do as much damage as one would have expected. 

Why Agroecology is the future of food production: How to feed the land holobiont so that it feeds you

Ian Schindler is a mathematician originally from Los Angeles, now based in Toulouse (France). He has gradually moved his interests from pure mathematics to resource depletion and collapsology, and now he is interested in permaculture and holobionts.

By Ian Schindler

Agroecology aka restorative agriculture aka regenerative agriculture is characterized by:

1. Control of pests through biodiversity.  Thus no mono-cultures.

2. More labor as there are no mono-cultures so harvesting must be done with human labor.

3. Yields (for humans) are lower than with intensive farming but biomass is far greater than with intensive farming.

4. No (or very little) artificial fertilizers or pesticides are required.  

1- LaCanne and Lundgren 2018, https://doi.org/10.7717/peerj.4428 found fewer pests on agroecological farms than on the surrounding pesticide using farms.

2- The labor is much more intense the first few years. It is less monotonous than in intensive agriculture because there is no mono-cultures so it is less repetitive.  It is perhaps more rewarding if one enjoys contact with wildlife.

3- The biggest difference between intensive agriculture and agroecology is between the ears.  Different metrics are used to define success.  The goal in agroecology is to design a food producing, self-sustaining system.

4- The cost structure is quite different from intensive agriculture.  While intensive agriculture requires recurring high level investments, agroecology requires a high initial investment, but once the system starts self-sustaining, costs are very low.

Agroecology is essentially food production with the food kept in its holobiont. Globally about 50% of terrestrial biomass is below the surface of the soil. Of course there are plant roots, but according to Paul Stamets, about 1/3 of the carbon in the soil is contained in the mycelium of fungi. Fungi are particularly important in forests. Well informed practitioners of agroecology pay particular interest in the health of the soil. Note that in https://doi.org/10.7717/peerj.4428 the authors found profit was not correlated with yield, but it was correlated with soil quality. It can take several years to obtain high quality soil. The fastest way to improve the soil is to add animal excrement (herbivore excrement works the best). Plants help to improve the soil. Plants growing in poor soil will devote at least 1/4 of their photosynthesis to creating sugars excreted by their root systems to encourage bacterial and fungal growth.

Agroecology addresses  the following problems:

1. Climate change.  
2. Mitigating the effects of climate change.
3. Peak oil.
4. Peak soil (https://energyskeptic.com/2017/peaksoil/).
5. Peak water (http://encyclopedia.uia.org/en/problem/135192 and
   https://science.sciencemag.org/content/372/6540/418).
6. Decreasing biodiversity
7. A declining agricultural population.
8. Public health.
9. World hunger
10. Water pollution.

1- At least 1/4 of all greenhouse gas emissions come from land use while all of transportation is less than 15% (see
https://www.epa.gov/ghgemissions/global-greenhouse-gas-emissions-data and
https://doi.org/10.1088/1748-9326/ac018e). Switching to agroecology would transform land use from a source of CO2 emissions to a sink (see https://4p1000.org/).

2- Two of the primary characteristics of high quality soil are increased water capacity and resistance to erosion. High quality soil does not wash away in heavy rain and is more resilient to drought as it can store more water.  Because the soil can absorb more water, flooding is reduced in the case of very heavy precipitation.

3- Agroecology is far less energy intensive than intensive agriculture.  In the U.S., to produce 1.75 calories of food requires about 2 calories of energy inputs.  If one looks at the entire food process (packaging, processing, storage, etc.) 14 calories are required for every calorie consumed.  See
https://css.umich.edu/publications/factsheets/food/us-food-system-factsheet
and also https://www.postcarbon.org/publications/the-future-is-rural/

4- Agroecology creates soil rather than destroying soil.

5- Water management is a key feature of agroecology.  Ditches or swales are created to keep water from draining off the land.  On slopes retaining walls are built so that water can soak into the ground.  High quality soil reduces the need for irrigation.  In many biomes, irrigation is not required.

6- Because holobionts are preserved, so is biodiversity.  

7- The average age of a farmer, both in the U.S. and Europe is greater than 55 years. In France, a farmer commits suicide every day. Many young people who would like to farm, would like to apply agroecological techniques. Currently they have difficulty getting bank loans and finding land to begin
their activity. At the 2022 commencement ceremony at AgroParisTech (a prestigious French agronomy school) several students took the stage, complained that they had been trained to destroy the planet, and voiced their intention of practicing agroecology. A link to a video of the event (in French): https://www.youtube.com/watch?v=SUOVOC2Kd50.

8- Food produced with agroecological methods is healthier.  For example the milk from cows fed on grass contains a higher ratio of Omega 3 fatty acids to Omega 6 fatty acids than the milk from cows fed soy.  See also https://www.goodreads.com/book/show/54785505-inflamed and https://book.umanaidoomd.com/.

9- Agribusiness pushes yield as a metric to solve world hunger. However the food produced by intensive agriculture is too expensive for people in poor countries (where labor is cheap). In fact this high yield food is exported from poor to rich countries leaving poor local people hungry. See https://www.scientificamerican.com/article/agroecology-is-the-solution-to-world-hunger/.

10- Agroecology actually purifies water.  See Dan Barber's talk linked to below.

Remarks:

1. Agroecology is a group effort.  It requires many people per unit area.    Currently woofers make up a large part of this effort: https://wwoof.net/.

2. Currently in France the profitable farms are either very large or very small (less than 2 hectares). The large farms are profitable because they receive the most subsidies from the European common  agriculture policy. In (Kirsch, Kroll, and Trouvé 2017 http://journals.openedition.org/economierurale/5223) the authors found that subsidies were positively correlated with pesticide use per unit area. Small farms are profitable because they sell directly to consumers.

3. Solutions are not unique. Sepp Holzer (http://www.seppholzer.info/) never prunes fruit trees but at the garden of the workers fraternity the fruit trees are pruned intensively (https://www.youtube.com/watch?v=2DVLlkToPuU).

4. Starting an agroecological project is not easy.  It can take up to 7    years for the system to stabilize.

5. Agroecology is profitable after the first few years. See    https://doi.org/10.7717/peerj.4428. There are many examples of successful farms practicing agroecology (see below).

6. Agroecology would require less land than industrial agriculture to feed the world.  Much land used in agriculture today is used to grow grain to feed animals.  It is a very inefficient system.

7. An efficient policy to encourage agroecology would be to pay farmers to sequester carbon.

Examples:

1. Agroecology is a key element of permaculture. David Holmgren, one of the founders of permaculture, has been successfully practicing agroecology since the the mid 1970s: https://holmgren.com.au/.

2. Dan Barber's wonderful 19 minute Ted talk: "How I Fell in Love With a Fish",
   https://www.ted.com/talks/dan_barber_how_i_fell_in_love_with_a_fish.

3. Kirsten Dirksen's 55 minute documentary on the Kailash Ecovillage in Portland, Oregon which is a mature, urban permaculture design. These people are not farmers, but part of their rent is participating in their own food production. They demolished parking lots to grow food. Note that they compost their own excrement on site:  https://www.youtube.com/watch?v=iCGXVk-cBVk.

4. Kirsten Dirksen's 53 minute documentary of a mature large agroecology farm in Wisconsin: https://www.youtube.com/watch?v=sRPP4Ilpxso

5. Sepp Holzer: http://www.seppholzer.info/

6. Jean-Martin Fortier: https://en.wikipedia.org/wiki/Jean-Martin_Fortier

7. The Garden of the Worker's Fraternity in Moscou, Belgium grows with agroecology since 1969 (in French): https://www.youtube.com/watch?v=_dNKG20-GrE

8. "The Biggest Little Farm" is an excellent documentary on the 80 hectare Apricot Lanes Farm (https://www.apricotlanefarms.com/) in Moorpark, California.

Survival of the fittest or non-survival of the unfit? How the theory of evolution has evolved.

Lynn Margulis, one of the brightest minds of the 20th century, developer or co-developer of concepts such as "Gaia", "endosymbiosis," and "holobiont." Image from Gabriela Govantes Morales

Life did not take over the world by combat, but by networking.

Lynn Margulis

The first study in the field we call today the “science of complex systems” was Darwin’s synthesis of evolution by natural selection, in 1859 1. Initially, Darwin’s ideas were often understood as implying mainly competition (“Nature in red tooth and clay”). Nowadays, we tend to emphasize more the concept of collaboration, often in terms of the concept of “symbiosis” and of the paradigm that goes under the name of “holobiont,” an ensemble of creature that live together in a condition of symbiosis.

“Holobiont” is a term known from the 1930s 2, but the idea of collaboration among living beings, microorganisms in particular, is much older. It may go back to the concept of “consortia” developed in mid 19th century 3. Nowadays, it is mostly associated to the work of Lynn Margulis, who used it starting with the 1990 4 5, although she had been studying the subject already in the 1960s 6. The interest in holobionts has been rapidly growing with the 2000s 2 and that led to a variety of different interpretations of what exactly a holobiont is. Here, I am not even trying to provide a comprehensive discussion of the many ways in which the holobiont concept is interpreted. Let’s say that the holobiont term can be seen as a meme growing in the memesphere 7 and, true to its evolutionary background, has been following a memetic evolutionary path, changing and adapting as its memetic environment changes.

The most common interpretation sees holobionts in a relatively narrow sense, as systems formed by a host organism and its associated symbiotic micro organisms, e.g. the gut bacteria of human beings (see, e.g. the work by Rosenberg 8. We can call this the “classical” view that focus on host-microbe interactions. A more general definition is provided by Castell and others 9, 10 in terms of the concept of “complex adaptive systems” (CAS) 11. CAS systems are formed of a network of elements (“nodes”) which, in this case, may consist of individual organisms or smaller holobionts, thus making the definition “fractal” or “self-similar.” The highest rank holobiont of the ecosystem is the ecosystem itself, that some call Gaia 12), 13.

The nodes (the creatures) of the holobiont network are connected to each other by flows of matter, energy, or information and are affected by “feedback” phenomena. The term “feedback“ indicates a condition that makes the flow proportional (or inversely proportional) to the status of the nodes they are connected to. It is the interplay of feedbacks that stabilizes the system and makes it tend to reach homeostasis. CAS systems have several typical characteristics, one is of reacting to perturbations by damping them and trying to maintain their state and reach the condition called “homeostasis.”

Castell et al. use the term “Holobiont-like system” (HLS) for these CAS systems that they describe as biological systems. In this paper, I’ll use the term “holobiont” as a general term that includes HLSs and I will argue that the “network” characteristics of these systems makes the definition applicable to non-biological systems, e.g. social and economic networks.

One characteristic of CAS is their capability to evolve. It is embedded in their tendency to react to external perturbations (called “forcings” in the jargon of system science) in order to attain homeostasis. Those systems which can do that tend to persist for a long time, so they are winners at the evolutionary game. But there is more to the concept of holobiont: it can be used to explain how evolution moves in steps by co-opting of different creatures in a single organism 6. According to Margulis 5, the unit of evolution is not the genome of individual organisms, but the “hologenome,” the ensemble of the genomes of the creatures that compose a holobiont. This concept is not without problems, in particular about what are the boundaries that define a specific holobiont, but it is gaining acceptance in the scientific community 14, 15.

The present paper is a review of the concept of “holobiont” aimed at developing mental tools helping us to understand how and why many complex systems around us exist and operate. The “holobiont paradigm” can help redress our views of the world and lead us to take a more collaborative attitude toward nature and our fellow humans. It is a way to change our current way of thinking and transform it into a gentler and more balanced view of the world, where we take what we need from Nature and give back to Nature what Nature needs. And the same concept holds for human life in human society.

Holobiont: how evolution has evolved


A well-known poem by Tennyson mentions “Nature in Red Tooth and Claw.” It was written in 1850, before Darwin’s book, “The Origin of Species”(1859), appeared in print. But, in time, Tennyson’s sentence started to be seen as embodying the very essence of Darwin’s ideas. It implied that the natural world is a continuous fight where the best individuals prevail and reproduce, while the others leave no descendants and disappear. During the 19th and 20th centuries, Darwin’s ideas were often coerced into a version that considered evolution as not a purely random phenomenon, but a purposeful motion toward creating species of higher and higher perfection 16. This distorted interpretation of Darwin’s ideas percolated into fields other than biology. Competition is often seen as the key element that makes it possible for people to become better at their jobs, for technology to improve, for companies to produce better products, and more. Even sports are always supposed to be competitive: from the time of Baron De Coubertin, we accept that we should let the stronger win the battle and the swifter the race (even though the Ecclesiastes book says otherwise). During the 20th century, distorted versions of Darwin’s theory were used to justify all sorts of crimes against humankind. Darwin himself would have been horrified if he had known that his ideas would have been used in this way.

The idea of the “survival of the fittest” is not wrong, but it has created a lot of confusion about how exactly natural selection works. Darwin emphasized the survival of the fittest because of his reliance on human breeding of domesticated animals and plants as examples. Human-led selection is focused on forcing species to acquire one or a few specific characteristics that humans find useful. The results are optimized, but only for that characteristic, often at the expense of many others that are needed for survival in the wild. Horses can be optimized for their ability to run, donkeys for their ability to carry weights, grains for the size of their eaves, apples for their taste and size, and there are many more similar cases. But most of the creatures optimized by humans would not survive for long in the wild. It is similar to the mitochondria in eukaryotes, which could not survive outside the larger cells they populate. Individual organisms rarely survive alone: mostly they are part of groups (herds, flocks, prides, etc.) that provide shelter, protection, and more. A fitter animal still needs to be part of a group, and that limits the advantage of being special. Rather than for the fittest, evolution strives for the not so bad.

An example. Think of a herd of wild zebras. The paradigm of “survival of the fittest” implies that zebras continuously evolve toward fitter and fitter creatures. Predators which attack zebras do the same. The result is called, sometimes, the “evolutionary arms race” between prey and predators 17. If we understand evolution at the individual level, we can imagine that it would result in creating a "super-zebra" that can run faster than the other zebras. Would that give it an evolutionary advantage?

We may not be so good a thinking like zebras, but it seems obvious that, for a zebra, survival is mostly guaranteed by being part of the herd. The herd will not directly fight back against predators (although in some cases it will, it is called "mobbing"), but it will provide early warning of the presence of predators, its movement will confuse them and single zebras will have a statistically better chance of survival. An isolated zebra has no chances to escape once it is the target of a group of predators, so being able to run very fast is probably a negative characteristic, especially considering that it could only be obtained at the expense of other useful characteristics, say, endurance, metabolic efficiency, or others. On the opposite side of fitness, instead, evolution works by removing the unfit. Clearly, zebras that cannot follow the herd are a preferred target for predators and their genes are removed from the gene pool. It is natural selection at work

Overall, therefore, the herd will be formed of individuals of similar characteristics. It is a typical holobiont formed by a group of individual organisms linked to each other, in this case mostly by visual signals. No zebra aims at helping its companions escape predators, but once they get together, their chance to be killed is reduced. A typical example of symbiosis. There is no altruism in symbiosis, only individual advantage. But that individual advantage benefits the whole group. The “hologenome” of the herd, the set of individual genomes, is the unit of evolution.

Once we define evolution in terms of holobionts, we can take a different look at the mechanism of selection. Darwin used the terms “survival of the fittest” and “natural selection” as nearly interchangeable ones, but that’s not the case. “Survival of the fittest” means that Nature selects in favor of the fitter creatures. “Natural selection,” instead, can be seen as meaning that nature selects against unfit creatures. The first interpretation (survival of the fittest) implies a continues evolution toward better and better fitness. The second (natural selection) implies a tendency toward stability or, using a more specific term, homeostasis.

The "removal of the unfit" is a fundamental concept. The biosphere, like any complex system, is subjected to an increase in disorder according to the 2nd law of thermodynamics. But the law applies only to isolated systems. The biosphere is not one, and it can keep entropy growth in check using natural selection to maintain homeostasis. The concept of evolution as the removal of the unfit was developed in particular by Gorshkov et al., 18 who put together a synthesis of how the ensemble of the living creatures on Earth (the biosphere) control the wider entity that we call the “ecosphere” generating the condition of dynamic stability we call “homeostasis.” This view was described in terms of the concept of “biotic regulation of the environment.” So, the biosphere does not normally aim at increasing the degree of fitness of individuals. The system strives for stability and the winners of the evolutionary game are those organisms which can best maintain it.

If stability is the aim of evolution, then, how does anything evolve at all? That is, how is it that Earth isn’t still populated only by marine prokaryotes, as it was during the Archean, billions of years ago? The holobiont paradigm helps resolve this problem, too, taking into account the phenomenon of “endosymbiosis,” the true motor of evolution.

Darwin’s ideas about evolution involved gradual and continuous change. The modern paradigm, called “neodarwinism” is based on molecular biology and assumes that evolution occurs as the result of modification of the genetic code of organisms, the result of either random mutation or sexual mixing (meiosis). In other words, evolution is a continuous “probing” of the fitness of organisms, where those better adapted at survival pass their genes to their descendants.

Yet, this interpretation has a problem. The gradual change of the genetic code can hardly account for the discrete evolutionary “jumps” needed to go from one species to another. This question was termed the “irreducible complexity problem” 19, and sometimes it was understood as implying the need to admit a supernatural intervention (“intelligent design”) to explain some features of living beings. A classic example is that of eyes. How could ancient, blind animals, develop eyes?

It is hard to find for eyes the same evidence of a gradual evolution that Darwin had observed for the beaks of finches in the Galápagos Islands. The first multicellular animals appeared at the time of the “Ediacaran Fauna” (also known as “Vendobionts”), some 600 million years ago. There is no evidence that these creatures had eyes. Instead, fully formed eyes clearly appear in the early Cambrian biota, starting from about 520 million years ago 20. So, we have this new evolutionary invention, eyes, that appear relatively suddenly, already in a functional form. How could it happen?

Attempts to solve the problem by postulating gradual steps were only partially successful. For instance, in 1994, Nilson and Pelger 21 proposed that a flat, light-sensitive surface could naturally turn into an eye-like optical structure in a few hundred thousand years of gradual evolution. It may be a correct estimate, but where did the light-sensitive surface come from? What benefit could early animals have from such a capability?

The concept of endosymbiosis gives us a way to explain this and many more evolutionary rapid changes. Endosymbiosis assumes that multicellular creatures are collections of formerly independent unicellular organisms. We may assume that early multicellular organisms co-opted microorganisms that had developed the stigma, a feature still present in some modern microorganisms. The stigma is a pigmented area in the cell connected to photoreceptor molecules. These molecules directly act on the flagellum (the “tail” of the creature). In this way, the microorganism can detect light and move toward it. It is typical of a creature called euglena, a protist that is both plant and animal. It uses photosynthesis – hence it is a plant – but it also moves, a characteristic of animals. There is no doubt that having a photosensitive receptor gives to the euglena an evolutionary advantage: it can move toward the light, which it needs for its photosynthetic activity. Light-sensitive microorganisms (not necessarily the euglena, which is a modern organism) give us the key to solve the “irreducible complexity” problem. Animals didn’t need to develop eyes from scratch. They borrowed light-sensitive organs by entering into a symbiotic relationship with unicellular creatures that had developed them. Later, they gradually turned these light-sensitive layers into organs able to form an image of the external world -- the organs we call “eyes.” This point is very general and another example of the usefulness of the concept of “holobiont”. There are many issues in evolution that cannot be solved unless we recur to the concept of endosymbiosis.

 
This point is very general. There are many issues in evolution that cannot be solved unless we recur to the concept of endosymbiosis. For another example, note how there are no intermediate species between prokaryotes (simple cells with no organelles) and eukaryotes (complex cells, with internal organelles) Nick Lane wrote a fascinating book in 2015 titled “The Vital Question,” (Lane 2015) dedicated to the attempt to explain why it is so. Clearly, we have another problem of irreducible complexity that can only be explained if we assume that what we call “organelles” are formerly independent organisms that were fagocitated by a larger cell and became part of it. This process is the basis of the concept of holobiont as proposed by Lynn Margulis (Sagan 1967), (L. Margulis 1975).

Once we define evolution in terms of holobionts, we can take a different look at the mechanism of selection. Darwin used the terms “survival of the fittest” and “natural selection” as nearly interchangeable ones, but that’s not the case. “Survival of the fittest” means that Nature selects in favor of the fitter creatures. “Natural selection,” instead, can be seen as meaning that nature selects against unfit creatures. The first interpretation (survival of the fittest) implies a continuous evolution toward better and better fitness. The second (natural selection) implies a tendency toward stability or, using a more specific term, homeostasis. It means that individuals seek for collaboration rather than competition -- a basic characteristic of holobionts. The winners of the evolutionary game are always good holobionts!




References

1. Charles Darwin. The Origin of Species. (John Murray, 1859).
2. Baedke, J., Fábregas‐Tejeda, A. & Delgado, A. N. The holobiont concept before Margulis. J. Exp. Zoolog. B Mol. Dev. Evol. 334, 149–155 (2020).
3. Kull, K. Ecosystems are Made of Semiosic Bonds: Consortia, Umwelten, Biophony and Ecological Codes. Biosemiotics 3, 347–357 (2010).
4. Margulis, L. Words as battle cries—symbiogenesis and the new field of endocytobiology. BioScience 40, 673–677 (1990).
5. Margulis, L. Symbiotic Planet: A New Look At Evolution. (Basic Books, 2008).
6. Sagan, L. On the origin of mitosing cells. J. Theor. Biol. 14, 225-IN6 (1967).
7. Dawkins, R. The selfish gene. (Oxford ; New York : Oxford University Press, 1976).
8. Rosenberg, E., Koren, O., Reshef, L., Efrony, R. & Zilber-Rosenberg, I. The role of microorganisms in coral health, disease and evolution. Nat. Rev. Microbiol. 5, 355–362 (2007).
9. Castell, W., Fleischmann, F., Heger, T. & Matyssek, R. Shaping Theoretic Foundations of Holobiont-Like Systems. in Progress in Botany 77 (eds. Lüttge, U., Cánovas, F. M. & Matyssek, R.) 219–244 (Springer International Publishing, 2016). doi:10.1007/978-3-319-25688-7_7.
10. Matyssek, R., Lüttge, U. & Castell, W. Evolution of Holobiont-Like Systems: From Individual to Composed Ecological and Global Units. in Progress in Botany 1–46 (Springer, 2022). doi:10.1007/124_2022_57.
11. Mobus, G. E. & Kalton, M. C. Principles of System Science. (Springer, 2015). doi:10.1007/978-I-4939-1920-8.
12. Matyssek, R. & Luttge, U. Gaia: The Planet Holobiont. Nova Acta Leopoldina 114, 325–344 (2013).
13. Castell, W., Lüttge, U. & Matyssek, R. Gaia—A Holobiont-like System Emerging From Interaction. in Emergence and Modularity in Life Sciences (eds. Wegner, L. H. & Lüttge, U.) 255–279 (Springer International Publishing, 2019). doi:10.1007/978-3-030-06128-9_12.
14. Gray, M. W. Lynn Margulis and the endosymbiont hypothesis: 50 years later. Mol. Biol. Cell 28, 1285–1287 (2017).
15. Morris, J. J. What is the hologenome concept of evolution? F1000Research 7, F1000 Faculty Rev-1664 (2018).
16. Bowler, P. J. The Non-Darwinian Revolution: Reinterpreting a Historical Myth. (Johns Hopkins Univ Pr, 1992).
17. Dawkins, R. The Blind Watchmaker. (Norton & Company, 1986).
18. Gorshkov, V. G., Makarʹeva, A. Mikhaĭlovna. & Gorshkov, V. V. Biotic regulation of the environment : key issue of global change. (Springer-Verlag, 2000).
19. Behe, M. J. Darwin’s Black Box: The Biochemical Challenge to Evolution. (Simon and Schuster, 2001).
20. Zhao, F., Bottjer, D. J., Hu, S., Yin, Z. & Zhu, M. Complexity and diversity of eyes in Early Cambrian ecosystems. Sci. Rep. 3, (2013).
21. Nilsson, D. E. & Pelger, S. A pessimistic estimate of the time required for an eye to evolve. Proc. Biol. Sci. 256, 53–58 (1994).
22. Jensen, K. H. & Zwieniecki, M. A. Physical Limits to Leaf Size in Tall Trees. Phys. Rev. Lett. 110, 018104 (2013).

Do we focus too much on CO2 alone? An appeal for the conservation of natural ecosystems

 

Image from the University of Toronto. 

Have we exaggerated with the idea that CO2 -- carbon dioxide -- is the arch villain of the story? Aren't we overemphasizing solutions that imply CO2 removal? How about geoengineering, sometimes touted as "the" solution that will allow us to keep going on burning fossil fuels? 

There is no doubt that the emissions of carbon dioxide are returning the ecosystem to a condition that was never seen before at least one million years ago. There is no doubt that CO2 is warming the planet and that none of our Sapiens ancestors ever breathed in an atmosphere that contains a concentration of CO2 of 420 parts per million -- as we are doing. 

But by focussing so much on CO2 alone is easy to forget what humans have been doing to the ecosystems that keep the biosphere alive (and with it, humankind). The ecosystem is a giant holobiont that strives for stability: a fundamental element to stabilize Earth's climate. It is a dangerous illusion to think that we, humans, can replace the work of Gaia with our fancy carbon capture machinery, or whatever other tricks we may concoct. 

Here is a reminder by a group of people from Eastern Europe who managed to maintain a certain degree of mental sanity. They remind us of the damage we are doing. Will anyone listen to them? (UB)

Appeal to the international community, governments, scientific, public organizations and business

https://www.es-partnership.org/wp-content/uploads/2021/06/Appeal_Protect-Ecosystems.pdf

RECOGNIZE THE VALUE AND ROLE OF NATURAL ECOSYSTEMS FOR CLIMATE CHANGE!

Terrestrial and marine natural ecosystems are the basis for preservation of biological life on Earth. They have existed almost unchanged for millions of years and all this time have supported climate stability, biochemical flows, global water circulation and many other processes, irreplaceable and essential for preservation of life on our planet. Undisturbed natural ecosystems maintain the Earth's temperature, suitable for human life.

The laws of nature are the basis of life on Earth, and all the laws of human society that regulate economic, political, social and cultural relations are secondary to them and must take into account the biosphere’s operating principles and man’s place in it.

However, over the past decades, human activities aimed at meeting the needs for food, energy and 
water have caused unprecedented changes in ecosystems, including land degradation and deforestation. These changes have helped improve the lives of billions of people, but at the same time, they have destroyed nature's ability to regulate the environment and maintain the climate.

According to current estimates, more than 75% of natural ecosystems are subject to degradation and loss of their functions, which undermines all efforts to preserve the climate and threatens the achievement of SDGs, including hunger, disease and poverty eradication. 

Humanity is standing on the edge of a precipice. Over-threshold disturbance of ecosystems leads to
irreversible loss of the gene pool, up to complete disappearance of ecosystems. In the face of growing efforts and understanding of the threat of climate change, it is now necessary to recognize and support the unique role of natural ecosystems in preserving the climate and a vital environment. International climate policy adjustments and fundamental changes in national development strategies are required.

We call to wake up and recognize the fundamental and irreplaceable value of natural ecosystems and for strong and urgent action, including:

1.  To recognize the goal of preserving natural ecosystems as humanity’s highest priority and stop their further destruction through adopting a global moratorium on any further development of territories still untouched by human activities, with international support mechanisms, including funding.
2.  Promotion of large-scale natural reforestation is an urgent task. Climate-regulating functions of forests, associated with the ability to retain soil moisture and maintain continental water transfer, are their main value, which are orders of magnitude higher than the cost of wood. Undisturbed forests should be completely removed from economic activity by law and allocated to a separate category with the maximum degree of protection. 
3. At all levels, from international to regional, national and local, it is necessary to review ongoing development strategies and take urgent measures to protect natural ecosystems and wildlife. It is necessary to adjust all sectoral policies, including agricultural practices, in order not only to meet the demand for food, but also to minimize the burden on natural ecosystems
4. A transition from conventional sectoral management to basin and ecosystem management is required, including raising the status of nature conservation goals. Water resources management should ensure that natural ecosystems are guaranteed priority in water supply that is necessary for their conservation, as well as protection and restoration of aquatic and other ecosystems - from mountains and glaciers to deltas and reservoirs.
5. Measures aimed at preserving natural ecosystems also require a review of existing incentives and tools and creation of new ones, so that ecosystem services are no longer perceived as free and unlimited, and their management takes into account the interests and roles of the populations and local communities which directly depend on them and are their custodians.

--------------------------------------------------------------------------------------------------------------------------

International Socio-Ecological Union, Eco-Forum (of 54 public organizations) of Kazakhstan, 
Association (non-governmental organizations) «For Sustainable Human Development of Armenia»,
Eco-Forum (independent non-governmental organizations) of Uzbekistan, as well as professional and non-governmental organizations of Armenia, Moldova, Russia, USA and others

Can our bacteria and virus friends save us? The rise of psychobiotic therapies for the human holobiont

 

The effect of the gut microbiota on the brain in the human holobiont is an incredibly complex story. It is described in a review appeared in 2019 on the "Physiological Reviews" journal. Not so much a review as a whole treatise, it is huge, with 1694 references in the bibliography!!! You can find a more readable summari on the blog "gut microbiota for health"

Before going on, a note of caution: as it is the rule nowadays, most of what appears in the medical literature is biased or simply false as the result of the widespread corruption of the medical research system. This review has been partly sponsored by the pharmaceutical industry, nevertheless it seems reasonably free of hype for specific treatments or wonder drugs. Its approach is correctly evolutionary, for instance when they say:

"Given that there has never been a time when mammals existed without microbes (apart from under highly restrictive laboratory conditions), there has also never been a time when the brain has been without signals from the gut, and it is important to consider the relationship between the host and its microbiota from an evolutionary perspective"

And they have it perfectly right when they use the magic word "holobiont"!!!

"The hologenome theory may even account for complex biological phenomena such as certain behaviors. For instance, behavior that facilitates social interaction among holobionts might be considered evolutionarily adaptive/advantageous as it gives rise to greater transmission of microbiota, thereby enhancing genetic variation (1285, 1286, 1689). In light of these inextricable links between the microbiota and the brain throughout evolutionary history, it is imperative for the study of our own biology (and that of the entire animal kingdom) to understand how microbial symbionts influence brain physiology and behavior."

The main point of the paper is that the human brain is strongly influenced by the gut, that our behavior, to the point that modifying the gut composition can be seen as a form of "psychobiotic therapy" that improves plenty of pathological situations and improves also the quality of life, for instance helping against depression. 

Seeing how the world is behaving nowadays, it would seem that the human microbiome is in bad conditions, indeed. Especially the gut of our leaders seems to have been invaded by micro-monsters instead of the beneficial gut flora that's normal for humans. And, surely, the various habits of hyper-cleaning, distancing, and self-suffocation that became fashionable during the past two years didn't help in improving the situation. Maybe, at this point, only our bacterial and viral friends can help us (with a little support also from our friendly archaea and fungi). Go, friends, go! We need you badly! 

The epidemic of obesity keeps getting worse. What's a good holobiont supposed to do?

 

The obesity epidemic keeps expanding. The above are, I believe, the most recent data available for the US. The COVID-19 lockdowns and isolation measures are reported having made things even worse. This trend is simply horrendous: what the heck is happening to humankind? (Disclaimer: I am not a nutritionist, I am just someone who is fascinated by data and trends. And, of course, we are all interested in our health! Here, I report some data I found, hoping you may find them useful. Don't take them as the last word on the subject. As always, before acting on things that affect your health, do your own search and use your judgement about what works for you.)

The obesity epidemics had a considerable boost by the lockdowns during the Covid-19 pandemic. Coupled with the opposite effect, that obesity is a risk factor for people who contract Covid, you have a remarkable disaster in the making. With several Western countries having percentages of obese people close to or higher than 50%, one wonders what's going to happen in the future. Why are the human holobionts in such a poor shape?

The story is complicated, and I don't pretend to say anything new. I just want to attract your attention to some recent studies that I think shed some light on the mechanism of human obesity (but even our fellow dog holobionts are suffering from obesity). 

First, the work by Raubenheimer and Simpson on the food preference of various animals, summarized in a recent book titled, "Eat like the Animals." (Mariner Books, 2021). Their discovery is easy to summarize: it seems that most living beings have a specific set point in their needs for the main nutrients. They seek for a specific balance among proteins, fats, and carbohydrates. In particular, they aim at a minimum intake of protein. If animals are fed an unbalanced diet, for instance, poor in protein, they will tend to eat more food until they reach the right level. Raubenheimer and Simpson call this the "protein leverage hypothesis:" 

"In a protein-poor but energy-rich food environment, humans will overeat carbs and fats to try to reach their protein target. However, when the only available diet is rich in protein, human will underconsume carbs and fats"

Since excess carbohydrates are stored in the body as fat, we can say that one of the causes of the obesity pandemic is that the human diet in Western countries is overstocked in carbohydrates. 

Here comes Robert Lustig and his book "Metabolical" (Yellow Kite 2021) where he minces no words on how this is not only true but also a profitable strategy for the food industry. They discovered long ago that if they put more and more carbohydrates (sugars) in the food they sell, then people will get fat, they will eat more, and that will increase their profits. Just like sick people are a boon for medical doctors, obese people are a boon for food producers. 

You don't believe that? Let me show you a picture I took a few days ago in an Italian supermarket:

There are four kinds of regular mayonnaise on sale, plus a fancy one with no eggs. Can you guess which is the only one that does not contain added carbohydrates? Let me tell you, it is the most expensive one among the regular ones. All the others contain sugar. Maybe it is not the same for all mayonnaise brands on the market, but I think it is significant. Food companies do add sugar everywhere, even when it is not called for by the traditional recipes. They deny that, but it is written on the list of the ingredients (I have pictures, if you don't believe me!)

Now, it may well be that there is much more to obesity than just carbohydrates, but I think that these results point at an important cause of the problem. There are data showing that what we are seeing may be a delayed effect of "peak sugar" that occurred around the year 2000. From then on, the amount of sugar consumed in the U.S. has been going slightly down. But it remains high. 

The beauty of this is that, if it is true, with obesity we don't have such a wicked problem as others, say, global warming. We know that to avoid global warming, we should stop burning hydrocarbons, but it is also true that we can't just stop: billions of people would die. But we could stop, or at least strongly reduce, the extra carbohydrates added to processed food, and we could do it today. Nobody would die, but the problem would be eased and many people would be healthier! But this is the way things are in the world: no problem can ever be solved when there is somebody making money if it remains unsolved. 

To make you happier, let me show you some data that tell us that a little excess weight (a little!) is not necessarily bad for your organism. Here are some data from Malcolm Kendrick's wonderful book "The Clot Thickens" (Columbus 2021). 

BMI stands for "Body Mass Index" and the overall lowest risk of death is for a BMI of 25-30 that's normally classified as "overweight" (if you want to know, I am at BMI=27). Being underweight is a larger risk than being obese! But obesity has many other problems, not least in terms of self-esteem. 

In the end, remember that you are a holobiont and that for hundreds of millions of years your holobiont ancestors never ate anything that was processed in an industrial plant. You are a fine-tuned machine that includes trillions of friendly viruses and bacteria living in your guts. They want a balanced diet of fats, protein, fiber, and not too much in terms of carbohydrates (but you need them, too!). Try to make them happy, and you'll be happier, too!

Gaia's One Billion Years Task: Colonizing the Land

 

Gaia as the sea Goddess Grammamare according to Hayao Miyazaki's interpretation in the film "Ponyo"

Imagine a time machine that brings you back to the Earth of one billion years ago, right in the middle of the eon called the "Proterozoic." First of all, you need an oxygen respirator, otherwise you'll die of suffocation in a few minutes. You also need a wide-brimmed hat and an outfit that covers your limbs in such a way as to protect your skin from the ultraviolet radiation. It is your planet, but in this period it is not especially friendly to a metazoan as you are.

You walk a few cautious steps onward. In front of you, the blue sea. You turn around: an expanse of dry rocks that continues all the way to the horizon. No traces of anything green that you can see: no plants, no insects, no birds, nothing like that. Above you, the sun is bright in the blue sky. You notice that it is a little less bright than you are used to seeing it, in your time. No traces of clouds: it is what you expected: no trees means no evapotranspiration of water vapor, no volatile organic compounds to function as nucleation sites for the water droplets that form clouds. 

You walk toward the sea. There are mainly rocks, but also some sandy places: small patches of beach. If there is a beach, there has to be a river, somewhere, that created it. You see it, not far away. It is completely dry, its bed going straight through the rocky landscape from the hills in the distance. Rains, when they arrive, must be torrential downpours that come and go quickly. 

You kneel on the beach, in front of the sea, lifting some water with your cupped hands. You know that it should be less salty than the seawater you are used to in your time, and you are tempted to taste it to confirm. But that is not a good idea. That water is brimming with microorganisms, most of them unlike anything your immune system is used to. You drop the water on the surface of a rock, where it forms a dark spot that rapidly evaporates and disappears. 

Standing up in front of that alien sea, you look at the gentle waves coming and going. You know that there are no fish in there. No crabs, no seashells, no seaweed, nothing like that. But there are enormous numbers of microorganisms. They are photosynthesizing, eating each other, reproducing by splitting themselves in two. They can live only in water. Is there life on the dry rocks on the shore? Maybe some of those microscopic creatures survive there, maybe even thrive, perhaps algae or even ancestors of modern lichens. But they are just eking out a precarious existence. They are invisible to the naked eye, and their time has not come yet.

On the horizon, an enormous orange moon rises as the sun slowly fades on the opposite side. You keep looking at the dark waters in front of you. Just under the surface, you glimpse something that looks like a pair of large eyes. You think you see her just for a moment, Gaia in her form of sea goddess, languidly swimming in the calm sea. 

____________________________________________________

Back to your time machine. You dial 350 million years before your time, the start of the Carboniferous Period. You press the button. 

You emerge out of the machine, breathing the fresh air, smelling something you had never smelled before. Whatever it is, the air is humid, rich in oxygen. You are in a small clearing, in front of you, there is a pond surrounded by a lush forest. Trees, tall trees, forming a full canopy under the low clouds, swept by a gentle wind. The place is eerily silent: no birds, no insects, nothing like that. Yet, you recognize the place: this is your planet, Earth, not yet the way it will be in the future that is your time, but a familiar world. 

As you stand, a noise comes to you: a buzz. You see something flying away, an insect of some kind. It starts raining. It is a warm, gentle downpour that wets you rapidly, but ends quickly. It has been enough to disturb the creatures living under the low bushes. You have a glimpse of them scuttling away: tetrapods, early amphibians. They jump into the water of the pond and then disappear. They are your ancestors, the ancestors of all the metazoans that will move on land in the future that's your time. 

As you walk, splashing your boots on the mud, you wonder how Gaia pulled this incredible trick: transforming the bare rock of entire continents into lush forests. While you think that, you have a glimpse of a pair of bright eyes staring at you from the canopy. You look up, and they disappear, leaving only a Cheshire-cat smile of the Goddess of the Forests, then she vanishes among the branches.

Images of the Goddess courtesy of "Mon Seul Desir"