The Small and the Big: Life's Fundamental Energetic Dichotomy

A biotic regulation perspective on Nate Hagens’ Behavioral Thermodynamics: the Maximum Power Principle, and how life defends itself against its biggest consumers.

In a concluding The Great Simplification podcast for 2025, Nate Hagens raised what can be called an epochal challenge: whether humans can turn intelligence into wisdom such that our inherently destructive tendencies, especially the urge to consume everything that can be consumed as fast as possible (the so-called Maximum Power Principle as applied to our civilization), can be kept in check both within our own species and in the biosphere as a whole, so as to ensure long-term persistence.

Since this is a major topic in biotic regulation research (see also the list of publications at the end of this post), I will briefly outline what I see as the essential biospheric context for this challenge.

Life has existed for about four billion years. If it had followed the Maximum Power Principle, this would suggest that the principle does not conflict with long-term persistence. On the other hand, as we can see from the example of our own species, which consumes energy at an extreme rate while destroying its surroundings, the Maximum Power Principle does conflict with persistence. This leads to the conclusion that life has not followed this principle, and that those living systems that did choose to follow it did not persist. This is the perspective I outline below, and I offer it for discussion.

Universal power consumption per unit live mass — one rhythm for all life?

If we talk about the Maximum Power Principle, meaning that under certain circumstances systems that maximize the rate of energy consumption become more competitive, then the notion of power has to be defined rigorously. What, exactly, is the power that is being maximized?

One natural variable to examine is power consumption per unit living mass. How much energy does a kilogram of living tissue consume per unit time? When we consider this across different life forms, a remarkable pattern emerges. Evolutionarily diverse organisms tend to metabolize energy at roughly the same rate, on the order of a few watts per kilogram.

Fig. 3 from “Mean mass-specific metabolic rates are strikingly similar across life’s major domains: Evidence for life’s metabolic optimum” illustrates this point.

This striking similarity, namely why unicells, green leaves (!), and humans all metabolize energy at similar rates, was first pointed out by Victor Gorshkov in 1981. At the time, however, the metabolic rates of the smallest organisms on Earth, prokaryotes, were largely unknown to biological theorists. It took several years of careful searching through specialized journals to assemble a broad enough dataset to show that this metabolic universality extends even to the tiniest forms of life.

As a side note, this was highly disruptive research. Before it was published in PNAS, it had been rejected by several journals. The prevailing view, promoted in particular by the Santa Fe Institute, was that all life forms should, supposedly subject to a few first principles, follow the same allometric scaling, according to which larger organisms have a lower power consumption rate per unit mass. Arguing for a size-independent metabolic universality for life was therefore not an easy task. For example, the authors even had to defend the title of their paper, as the editors suggested removing the word “optimum.” Yet, to be fair to the ecological science community, these difficulties were nowhere near what we later experienced with the biotic pump.

Life’s metabolic optimum indicates that strong constraints on energy consumption are imposed by the evolutionary process. Life not only shares the same DNA code, but also beats to the same underlying rhythm.

The big and the small: a fundamental energetic dichotomy

Nevertheless, body size alone makes a major difference in total energy consumption. Whatever their mass-specific rates, an elephant consumes far more energy per unit time than a bacterium. Does that make the elephant more competitive?

To explore this question, we now turn to another variable — power consumption per unit body surface area, defined as the organism’s projected area on the ground surface. That is, we take an organism and determine the area of its projection onto the ground, essentially how it would be seen from space. We then take its total power consumption and divide it by this area. Instead of watts per kilogram, we are now dealing with watts per square meter.

When we plot area-specific power consumption across different life forms, another robust pattern emerges. As organisms grow larger, their power consumption per unit area increases systematically. The reason is straightforward. Larger organisms are thicker, so more universally metabolizing living mass is stacked above the same ground area, leading inevitably to higher power consumption per unit area. (This increase would not be inevitable if energy consumption per unit mass declined sufficiently rapidly with increasing body size.)

The primary producers absorb sunlight and produce food for the rest of the biosphere at a rate on the order of one watt per square meter or less. This creates a fundamental division among organisms into the small and the big. The small are those that consume, at the local spot their bodies occupy, less than or equal to the power that primary producers are able to synthesize.

Power consumption per unit area across different life forms as a function of body size (from “Life’s Energy and Information: Contrasting Evolution of Volume- versus Surface-Specific Rates of Energy Consumption”). This energetic portrait of life could be taught in schools, as it offers insight into many crucial aspects of life’s organization. Yet it largely remains unknown

Such small organisms can live on a continuous flow of energy without disturbing standing biomass stocks. What does this mean in practice? Living plants form the energetic foundation of the biosphere. They produce organic matter at a certain rate, after which they or their parts, such as leaves, die and are renewed. Small organisms like bacteria and fungi can literally sit under a tree and feed on the ongoing flow of dead organic matter without disturbing the living plants.

The situation is fundamentally different for large organisms that consume, at the local spot their bodies occupy, much more power than plants are able to synthesize. Mammals and birds, for example, consume hundreds of times more, as illustrated in the figure above. Such organisms cannot remain immobile, as this is energetically prohibited. They must inevitably move and draw on energy stocks accumulated elsewhere. On land, the primary energy stocks are the living plants themselves. As a result, large organisms must consume and destroy living plants, or feed on organisms that do.

This contrast captures a basic energetic divide of life. The small can live on energy flows, whereas the big must consume energy stocks. The small can remain sedentary, whereas the big must move. Obviously, the precise quantitative distinction between the small and the big, as well as the boundary between immobility and locomotion, depends on the magnitude of the energy flows available in a given ecosystem.

The small can live on energy flows; the big must consume energy stocks
The small can be sedentary; for the big, locomotion is a must

It is to those organisms that move and compete for energy stocks that the Maximum Power Principle can be readily applied.

But this raises an obvious question. If large animals were to compete with one another strictly under the Maximum Power Principle (MPP), why did they not exterminate all energy stocks, namely living plants, and thereby destroy all life? How was life able to prevent such an outcome?

Life’s defense against the biggest consumers

Since the largest consumers must move, as dictated by the law of energy conservation, and since locomotion is energetically costly, an obvious defense against systems driven by the Maximum Power Principle is a spatially diluted energy stock. If food is sparse and widely scattered, an animal will become exhausted long before it can consume all available energy stocks and destroy the vegetation.

In other words, to prevent the extermination of living biomass by the largest consumers, that biomass must remain scarce at any given location.

This is exactly how the cradle of life, the ocean, is organized. When you look into the clear waters of the open sea, there seems to be almost nothing there. Primary producers are tiny, often invisible phytoplankton cells. And yet, their global biomass amounts to only about 1.5 gigatons of carbon. By comparison, the terrestrial biosphere contains more than 400 gigatons of carbon in living plants, roughly two orders of magnitude more.

Remarkably, despite this enormous difference in standing biomass, the ocean and the land biosphere have comparable primary productivity, each fixing on the order of 50 gigatons of carbon per year. In the ocean, production is achieved not by large stocks of biomass, but by rapid turnover of extremely small producers. This organization makes it effectively impossible for large consumers to deplete living biomass locally, and thus acts as a powerful defense against MPP-driven overconsumption (for figures and references, see this publication).

With such a diluted resource base, the largest consumers are forced to feed on the few locations where energy stocks are occasionally more concentrated, but in general they cannot appropriate a significant fraction of the ecosystem’s energy flow.

For example, today there is, fortunately, a slow recovery of marine animal biomass, including whales. Before large-scale commercial whaling began around 1850, however, the cumulative biomass of marine mammals has been estimated at about 130 Mt. This corresponds to a total metabolic power consumption of roughly 400 billion watts, assuming a mean mass-specific metabolic rate of 3 W kg⁻¹.

The estimated global biomass of wild marine mammals since 1850, Fig. 2 from Greenspoon et al. 2025 “The global biomass of mammals since 1850”.

A total oceanic primary productivity of about 50 GtC yr⁻¹ corresponds to roughly 6 × 10¹³ W, that is, about sixty thousand billion watts. Against this background, the combined metabolic power of the largest marine consumers before industrial whaling, of order 4 × 10¹¹ W, amounted to well below one percent of the total ecosystem energy flow.

In other words, even at their historical peak, the biggest consumers were collectively allowed to appropriate only a very small fraction of the energy generated by primary producers. Their potential to destroy primary production was tightly constrained by the organization of the ecosystem itself, which favors extremely sparse standing biomass stocks and thus limits resource abundance.

As a side but important note, related cross-disciplinary notions include the resource curse and enshittification, the latter being associated with an increase in the size and power of resource-concentrating entities. Life as a whole has escaped enshittification because its energetic base, sunlight, exists only as a flow. Its stock is effectively zero: photons are massless and, unlike biomass, do not accumulate and therefore cannot be concentrated.

One may say that the largest consumers are life’s continuous headache, in the sense that their destructive potential must constantly be kept in check. When this control fails, large consumers can overexploit the ecosystem base, a pattern that likely underlies many extinction events and episodes of abrupt ecosystem disintegration in Earth’s history. That we tend to overlook this mechanism today is due, in part, to our habit of ignoring the active role of the biota in stabilizing the environment and the climate, and in part to the fact that, unlike external shocks such as meteorite impacts, internal ecosystem disintegration often leaves no clear external signature.

In boreal forests, beavers fell so many big trees that researchers have asked, “How have North American forests survived?” (Johnston and Naiman 1990, Browse selection by beaver: effects on riparian forest composition, Canadian Journal of Forest Research, 20, 1036–1043). Fortunately, beavers are tightly constrained to water bodies, which occupy only a minor fraction of forested landscapes. This evolutionary confinement strictly limits their cumulative impact. Had beavers evolved the ability to disconnect from aquatic environments, large areas of boreal forest would likely have been eliminated.

On the other hand, when their destructive potential is successfully constrained, large consumers can be recruited to perform many useful functions within ecosystems. This sharpens a fundamental question: was the evolutionary appearance of large animals that destroy living biomass a bug or a feature of life’s eternal algorithm?

A human outlook

Unfortunately, unlike in the ocean, energy stocks on land cannot be strongly diluted. The large structures of trees are essential for operating the biotic pump and delivering moisture inland, which necessarily entails the presence of abundant biomass and large energy stocks. If trees, like corals, could be built from an energy-depleted material such as calcium carbonate, terrestrial ecosystems would be better protected. But calcium on land is far less available than carbon, so trees are built from energy-rich carbohydrates. Even though woody tissues are largely metabolically inactive, they store large amounts of energy. As a result, terrestrial ecosystems are inherently more vulnerable to their largest consumers than the ocean.

Yet even on land, in stable ecosystems such as intact forests, life has managed to limit the share of ecosystem productivity allocated to the largest animals to around one percent.

Distribution of consumption of plant production in stable forest ecosystems. Unicellular organisms have controlled energy consumption at all times from the very beginning of life: in the modern biosphere over 90 % of plant production is consumed by the smallest organisms (bacteria and fungi). Arthropods, the smallest mobile animals, consume about 10% of primary productivity. Dark pink diagram shows consumption of the largest forest herbivores (mammals and birds) in the boreal zone, around 1%. From “Body size, energy consumption and allometric scaling: a new dimension in the diversity-stability debate”.

Humans have discovered a stock of energy that was carefully hidden by past life. By exploiting this stock, fossil fuels, humanity increased in number and activity to a level at which it consumes ecosystem productivity far above the ecologically safe limit of about one percent.

Victor Gorshkov estimated human appropriation of biospheric net productivity in a Russian-language paper published in 1981 (submitted in 1980). In the same 1980, these results were published in English in co-authorship with V. Dolnik in Soviet Physics Uspekhi “Energetics of the Biosphere”. In 1987, Vitousek and colleagues published similar results. Vitousek et al.’s paper received 2000+ citations. Gorshkov’s work, including the above distribution of energy consumption over body size, remains largely unknown.

This is not coexistence with the rest of life. The roughly ten percent of terrestrial productivity now appropriated by human food production, livestock fodder, and wood extraction was previously used by diverse natural ecosystems that regulated the environment and climate. As this share was redirected to human use, the regulatory capacity of the biosphere was diminished, and climate destabilization followed.

Large organisms have a low surface-to-volume ratio, so most of their metabolic power is devoted to maintaining internal homeostasis rather than interacting with and regulating the environment. As a result, transferring power from the smallest to the largest organisms undermines environmental stability. A similar impairment occurs in the economy under monopolization, which in effect represents the same process: a transfer of power from a large number of small actors to a single large one.

Fossil fuels will soon be exhausted, and human energy consumption will decline accordingly. This is not exceptional. Many populations in the past have collapsed once their resource base was depleted. What remains available, however, are trees and forests, which represent a major standing energy stock. Even relatively small human populations were able to turn large parts of once-green Australia into desert by decimating tree cover. Conversely, even a very large human population, such as today’s, is theoretically capable of exercising far greater restraint and wisdom in how it treats its tree heritage.

In this sense, the epochal challenge of bending the Maximum Power Principle ultimately reduces to rethinking how we, large consumers evolved to destroy living biomass and demonstrably successful at doing so, value trees, the largest energy stock in the terrestrial biosphere. Trees are not a resource. If this realization were to be encoded into a future civilization, it would mark a transformation as profound, in its own way, as the origin of terrestrial life itself.

Relevant biotic regulation publications

• Gorshkov V.G. (1995) Physical and Biological Bases of Life Stability. Man, Biota, Environment. Springer: Berlin.

• Gorshkov V.G., Gorshkov V.V., Makarieva A.M. (2000) Biotic regulation of the environment: Key issue of global change. Springer-Praxis, London.

• Makarieva A.M., Gorshkov V.G., Li B.-L. (2004) Body size, energy consumption and allometric scaling: a new dimension in the diversity-stability debate. Ecological Complexity, 1, 139-175. https://doi.org/10.1016/j.ecocom.2004.02.003

• Makarieva A.M., Gorshkov V.G., Li B.-L., Chown S.L., Reich P.B., Gavrilov V.M. (2008) Mean mass-specific metabolic rates are strikingly similar across life's major domains: Evidence for life's metabolic optimum. Proceedings of the National Academy of Sciences U.S.A., 105, 16994-16999. https://doi.org/10.1073/pnas.0802148105

• Makarieva A., Gorshkov V., Wilderer P.A. (2016) What Can We Learn from Natural Ecosystems to Avoid a Civilization Breakdown?

• Gorshkov V.G., Makarieva A.M. (2020) Key ecological parameters of immotile versus locomotive life. Russian Journal of Ecosystem Ecology, 5(1). https://doi.org/10.21685/2500-0578-2020-1-1

• Nefiodov A.V. (2020) Universal patterns of matter and energy fluxes in land and ocean ecosystems. Russian Journal of Ecosystem Ecology, 5(1). https://doi.org/10.21685/2500-0578-2020-2-6

• Makarieva A.M., Nefiodov A.V., Li B.-L. (2020). Life’s energy and information: contrasting evolution of volume-versus surface-specific rates of energy consumption. Entropy, 22(9), 1025. https://doi.org/10.3390/e22091025

• see also https://bioticregulation.ru/tag.php?t=ecology

PS This is a topic I find deeply important and am still learning how to write about. I realize this is not exactly a Christmas post, but rather a dense and potentially provocative read. I would very much welcome your feedback.