Who’s on top?

Ascending the Trophic Pyramid

17 min readJan 29, 2018

Spacefaring Civilization and Galactic Ecology

While human beings are at or near the top of the trophic pyramid on Earth (there is, however, a certain ambiguity in asserting that humanity is the dominant species on the planet) — we can hunt any other species, but very few other species hunt us —our civilization has not yet expressed itself in a spacefaring context. If and when terrestrial civilization joins an ecosystem of spacefaring civilization, we do not know and cannot know at what level we will enter the trophic pyramid defined by the places that spacefaring civilizations assume within the structure of galactic ecology.

As biological beings, we do not get to choose the level of the trophic pyramid into which we are born, but in so far as there is an ecology of societies or civilizations, there is, or would be, a degree of choice in how that society is constituted relative to other societies. A civilization that was able to transcend its homeworld in order to seek its separate and equal station in galactic ecology, would have had thousands of years, if not tens or hundreds of thousands of years, to achieve a degree of autonomy from its biological origins.

Probably the biological origins of the intelligent progenitor species of a civilization would continue to influence the kind of spacefaring civilization that that species would build, but there is at least an element of deliberate choice involved, which holds out the possibility of ascending (or descending) the trophic pyramid defined by galactic ecology. So what is galactic ecology? Here is a description of the processes by which stars and galaxies evolve:

“The timescale for the Galactic ecology is determined by the rate of star formation and the lifetime of the most massive stars (a few million years). This ecology must have existed, though in gradually changing form, over the life of the Galaxy. It is driven by the energy flows from the massive stars, and the material cycle through these same stars. Carbon, and heavier elements, are created in the massive stars, and released through winds and supernova explosions. They cycle between the various phases of the interstellar medium, before again being incorporated into stars and, in some cases, planetary systems and life. Further star formation in a molecular cloud is self-regulated by the massive stars already forming, and by the cooling agents which are already present in it. These agents gradually change as the elemental abundances, particularly of carbon, increase as the Galaxy evolves.” (Michael G Burton, “Ecosystems, from life, to the Earth, to the Galaxy” 2001)

This is the ecosystem of matter and energy within which cosmological-scale spacefaring civilizations must derive their resources or fail to do so. Any civilization that expands until it incorporates several planetary systems or which endures over billions of years, must expand or endure in this context.

In the exposition that follows we will begin with planetary ecosystems and planetary civilizations before we pass on to spacefaring civilizations. The exposition that follows will first develop the idea of intelligent progenitors of civilization as keystone species of artificial ecosystems, then move on to intelligent mutualism in an intelligence-rich biosphere, at which point these ideas can be brought together in a discussion of keystone species in intelligence-rich biospheres, and concluding with some considerations on the possibility of an astroecology of spacefaring civilizations.

Intelligent Progenitors of Civilization

On several occasions I have used the phrase “intelligent progenitors of civilization,” and even as I have used this locution I have understood that it is awkward, but, in its favor, it is accurate and self-explanatory. When one attempts to think through the unprecedented, one often becomes acutely aware of the limitations of language, which has plenty of detailed terminology for the familiar, but lacks terms to describe or explain the unfamiliar. Since I often try to formulate formal concepts that are applicable to any civilization whatsoever, whether on Earth or elsewhere, I often run into the problem of identifying the beings that engage in civilizational construction, and this is how I arrived at the awkward but accurate “intelligent progenitors of civilization.” The alternative is to coin a new word, something that I also do with some frequency, but which is viewed with perhaps even more disdain than awkward locutions. (For example, in a comment on a Centuari Dreams post of mine, one reader expressed misgivings for my locution, “The Great Voluntaristic Divergence,” which involves no neologisms, but which nevertheless offended the linguistic propriety of at least one reader.)

One way to refer to the intelligent progenitors of civilization without coining a new word and without an excessively long locution would be to call them keystone species — a term already in use in ecology, and so subject to misunderstanding, but this misunderstanding may be something that, Judo-like, we can turn to our own advantage.

In The Biological Conception of Civilization I suggested that one way to conceptualize civilization is as a, “tightly-coupled cohort of co-evolving species dependent upon one another as a consequence of domestication.” In this sense, a civilization (or, at least, a biocentric civilization), is like a climax ecosystem, in which a large number of closely interconnected species sustains the biodiversity and biomass of a given habitat. In climax ecosystems the keystone species are often apex predators, and recent ecology, which has tended to distance itself from the terminology of “climax ecosystem,” has nevertheless come to understand that the elimination of a keystone species can have effects that ripple through the ecosystem from top to bottom — a process called trophic cascade.

Trophic cascades have been defined as follows:

“Trophic cascades in ecological communities are defined as the propagation of indirect effects between nonadjacent trophic levels in a food chain or food web. Typically, cascades are driven by predation from the top‐down, with altered herbivore densities mediating the ultimate effects on the biomass of primary producers.” (Trophic Cascades, by Daniel S. Gruner)

For a more intuitive approach to trophic cascades, I highly recommend the videos produced by Sustainable Human, such as How Wolves Change Rivers and How Whales Change Climate, which both give a simple and easy-to-understand exposition of large-scale ecosystem changes that result from the presence or absence of a keystone species.

Keystone species, moreover, have been defined as follows:

“A species whose importance to community and eco-system structure, composition, and function is dis-proportionately large relative to its abundance is referred to as a keystone species.” (Keystone Species, by Martin A. NUÑEZ and Romina D. DIMARCO)

Given the conception of civilization as a tightly-coupled cohort of coevoloving species, the intelligent progenitor of this tightly-coupled cohort of coevolving species is the keystone species of the artificial ecosystem created by civilization. Take away the keystone species, and that artificial ecosystem collapses, just as if you take away a keystone species from a climax ecosystem and the entire ecosystem may suffer a decline.

Much of the surface of Earth today is given over to the artificial ecosystems maintained by civilization, and inhabited by domesticated species like corn (maize) and cattle. Take away human beings, and this ecosystem would collapse. In other words, human beings are the keystone species for the ecosystems they have created in order to serve their own interests. There is, then, a parallelism between naturally occurring climax ecosystems with their keystone species and artificially constructed ecosystems with their intelligent progenitors, which have created an ecosystem dependent upon their ongoing intervention.

A trophic cascade in an artificial ecosystem would be the equivalent of civilizational collapse. Again, there is a parallelism with naturally occurring climax ecosystems. In Snowstorm Reflections on Collapse and Recovery and Epistemic Collapse I discussed Joseph Tainter’s conception of the collapse of complex societies, in which I quoted Tainter as follows:

“A society has collapsed when it displays a rapid, significant loss of an established level of sociopolitical complexity. The term ‘established level’ is important. To qualify as an instance of collapse a society must have been at, or developing toward, a level of complexity for more than one or two generations… The collapse, in turn, must be rapid — taking no more than a few decades — and must entail a substantial loss of sociopolitical structure.”

Similarly, when a climax ecosystem experiences a denudation event — like a catastrophic storm, or being entirely covered over by a volcanic eruption (whether by pyroclastic flow, volcanic ash, or lava) — relatively fragile keystone species are often the first to go extinct, and the ecosystem experiences a rapid decline into a state of lower biodiversity and quantitatively less biomass. In short, the weeds survive, and a long process of ecological succession is necessary to rebuild the biodiversity and biomass lost in the denudation event.

Political collapses such as Tainter describes are the denudation events of civilization, and they lead to a rapid decline of the society to a lower level of complexity. While in the political collapses we have seen in history the keystone species — human beings — have not gone extinct, the social elites and the institutions through which they have ruled (and through which they have maintained the delicate balance of civilization) have gone extinct. In the event of actual human extinction, the artificial ecosystems of civilization would disappear, rather than merely declining.

Intelligence-Rich Biospheres and Intelligent Mutualism

Intelligent progenitors of civilization could appear as a lone intelligent species in a biosphere otherwise bereft of intelligence, or they could appear in a biosphere in which intelligence is a common adaptation, or at least not a unique adaptation. The latter I call an intelligence-rich biosphere.

An intelligence-rich biosphere is a counterfactual thought experiment in which a planetary biosphere has two or more species that have evolved peer or near-peer intelligence with human beings. If we drop the threshold for peer intelligence to primate level intelligence, we live today in an intelligence-rich biosphere in which many primate species share a single biosphere; if we push up the threshold for peer intelligence to beyond human level, then we live today in an intelligence impoverished biosphere. In true Protagorean fashion, in which man is the measure of all things, we take human-level intelligence as our point of reference because we are human, but this choice is not merely anthropocentric.

Human-level intelligence enables large-scale social cooperation that we do not see in other species, and this degree and sophistication of intra-human cooperation has made it possible for human beings to create institutions as comprehensive as civilization, for which there is no parallel in the natural world prior to the Neolithic. (For a couple of academic studies on human cooperation cf. How is human cooperation different? by Alicia P. Melis and Dirk Semmann and Culture and the evolution of human cooperation by Robert Boyd and Peter J. Richerson.)

When distinct species cooperate for mutual benefit we call this mutualism. Human cooperation represents intra-species mutualism (and, of course we find intra-species cooperation in all species, and we find it especially in eusocial species, where cooperation is taken to the point of distinct phenotypes). Human cooperation is facilitated by intelligence, and it is the role of intelligence in human cooperation that has propelled human cooperation beyond that found either in mutualism or in eusocial intra-specific relations.

In an intelligence-rich biosphere, then, one would expect to see mutualism facilitated by intelligence occurring beyond the kind of intelligence-facilitated intra-specific cooperation we find among human beings, and which has given rise to human civilization. Wherever two or more intelligent species engaged in intelligence-facilitated mutualism there would be the possibility of human-level (or beyond) civilization construction. However, this could take place in the context of many such interactions. The competition of multiple instances of intelligence-facilitated mutualism might prove to accelerate intelligence-facilitated mutualism to a point of development beyond that of human civilization, or it might become so common that any individual instance is swamped by all the other instances, and no individual instance of mutualism is able to rise above the others. (The latter case might result in a different kind of high-level equilibrium trap in intelligence-rich biospheres.)

If we could define a measure of intelligence independent of human beings (an IQ valid for any species whatever), and additionally a measure of cooperation across species (i.e., mutualism), it might be possible to calculate the optimal number of intelligent species within a given biosphere for the production of civilization. Indeed, the number may well be one, which would explain why human beings are the only human-level intelligence on Earth and the only species to produce a civilization. Or the number may be two, or three, or more, and another planet with an intelligence-rich biosphere that produces the optimal number of intelligent species will have civilizations driven by mutualism at an order of magnitude greater than terrestrial mutualism and greater than human civilization.

Perhaps rather than identifying supercivilizations as I have in the past, as civilizations that are very old, very large, or very powerful, it might be better to reserve the term “supercivilization” for institutions such as this, i.e., civilizations emergent from mutualism that involves the intelligent cooperation of multiple intelligent progenitor species. From our experience on Earth we don’t have anything that corresponds to this, but extrapolating from the accomplishments of human cooperation and from the possibility of intelligent mutualism, we can imagine a civilization that is more than human civilization because it draws upon the diversity of multiple different kinds of intellects from multiple species.

Keystone Species in Intelligence-Rich Biospheres

The ideas of the role of intelligent progenitors of civilization as a keystone species in artificial ecosystems they create from domesticated species, and intelligent mutualism in an intelligence-rich biosphere, can now be brought together in a more comprehensive conception of the function of intelligence in nature.

In an intelligence-rich biosphere we would expect to find pervasive and extensive mutualisms that extend across multiple species and which effectively constitute tightly-coupled cohorts of evolving species, which is what I have called the biological conception of civilization. Such an intelligence-rich biosphere, then, might feature many such coevolving cohorts emerging from intelligence-facilitated mutualisms even without any of the other properties that human beings identify with civilizations — metallurgical technologies, monumental architecture, formalized media of exchange, cities, and so forth. Forms of social interactions radically different from any known of Earth would likely result from such a different evolutionary context.

In an intelligence-rich biosphere, any food web would be potentially an opportunity for intelligence-facilitated commensalism that would be structurally isomorphic with biocentric human civilizations (being a tightly-coupled cohort of evolving species) and that could outstrip the achievements of human biocentric civilization as a result of the possibilities of intelligent cooperation above and beyond the possibility within a single-intelligence biosphere.

In a biosphere not merely intelligence-rich, but intelligence-dense, the better part of a food web might be animated in its interspecies intersections by intelligent beings, intelligently participating in the food web. It would be difficult to imagine intelligent prey species rationally acquiescing to their predation in the interest of the ongoing functionality of the ecosystem of which they are a part, but such an attitude, inconceivable to us. could well be the imponderable of an alien mind of which we are constantly reminded by those who regard it as an impossible task to enter into the thought processes or motivations of a radically different mind.

What we know of trophic cascades suggests that the maintenance of biodiversity is not merely compatible with large numbers of individuals of species lower down on the trophic pyramid, but that the presence of apex predators actually enhances lower levels of the trophic pyramid, so that an intelligent prey species might rationally decide that it was in the self-interest of its species to maintain a food web in which it continued as prey to apex predators.

More likely than an intelligence-dense ecosystem would be a food web with two or three or a handful of intelligent species mutually participating in one and the same ecosystem. Perhaps more likely yet would be multiple food webs within a biome, probably overlapping, each of them dominated by a single intelligent species, so that the intelligent species would be in competition for shared resources — species on the margin of the food web which shaded over into another food web — but each was the master of its own trophic pyramid, even if the base of the pyramid adjoined other trophic pyramids, each with their apex (intelligent) predator on top.

Of course, while keystone species are often apex predators, and the structure that I have described above could constitute a stable ecology of multiple intelligent apex predators, keystone species are not always apex predators. But in the case described above of an intelligent prey species that acquiesces to its predation in the interest of avoiding a trophic cascade (being able, by reason of its intelligence, to rid the ecosystem of its apex predator, but choosing to allow it to remain in place for the ecological good of all), it is conceivable that intelligent keystone species that are not apex predators might cooperate even at the cost of their own lives.

Human beings are infrequently the prey of bears, cougars, and other apex predators, and we have the ability to exterminate these species, but we choose not to do so, even though it means limited predation by a species of very limited intelligence on the species with the highest intelligence in the biosphere. It took us a long time to get to the point, however. Up until the emergence of the modern environmental movement, human beings routinely killed rival predators, sending many into extinction, and making many more locally extinct. It was quite controversial when wolves were re-introduced into the wild in Yellowstone National Park, but the results to date have been promising, and this particular re-introduction of a predator species into the wild has become a textbook case in documenting trophic cascades.

Given this human example, we cannot dismiss the possibility of a keystone species both prey and intelligent that allowed for its continuing predation in the interest of the overall health of the biosphere. And if this is at least possible, cooperation of intelligent predator and intelligent prey in an relationship of intelligence-facilitated mutualism is possible. The possibility of intelligence occurring at different levels of the trophic pyramid, the possibility of cooperating across trophic levels, or even within a single trophic level, offers potential advantages beyond the top-down human model of artificial ecosystems maintained by an intelligent agent installing itself as a keystone species of the ecology that it creates around itself.

Biodiversity in an Intelligence-Rich Cosmos

To what extent can we extrapolate from ecological principles that hold within a planetary biosphere, as discussed above, to ecological principles for the cosmos entire? A detailed answer to this question might be characterized as an inquiry into astroecology. At present I want to focus on a small fragment of astroecology, which involves an extrapolation of the intelligence-rich biosphere thought experiment to the cosmos at large. For an intelligence-rich cosmos would be an intelligence-rich ecology at a scale greater than a planetary biosphere.

Even if no one, single planet has an intelligence-rich biosphere, there could still be multiple intelligent species in the universe, in which case the cosmos itself could be intelligence-rich, or even intelligence-dense. This was once a common assumption, especially in SETI research. In Is Anyone Out There? by Frank Drake and Dava Sobel, the first chapter is titled, “Intimations of an Infinitely Populated Universe.” One would expect in an infinitely populated universe that such a universe would be intelligence-rich, if not intelligence-dense.

As an extrapolation of the continuum from an intelligence-impoverished biosphere to an intelligence-dense biosphere (i.e., the biospheric extrapolation of intelligence density), we can posit a continuum from an intelligence-impoversihed cosmos to an intelligence-dense cosmos (i.e., the cosmological extrapolation of intelligence density). Because of our own existence as an intelligent species, we can assert that the most intelligence-impoverished cosmos scenario is not instantiated by our universe, i.e., our universe is not a universe with no intelligent species whatsoever. A universe with a single intelligence species might be called a minimally-intelligent cosmos, and at the present time we do not know where our universe lies along the continuum from a minimally-intelligent cosmos (or, if you like, an intelligence-minimal cosmos) to an intelligence-dense cosmos.

While this question must remain unanswered for the present time, we can speculate that the existence of multiple intelligent species interacting within the universe would affect the total distribution of life and intelligence in the universe, just as the existence of multiple species interacting in a food web of the terrestrial biosphere affect the total distribution of life within the biosphere. Ecology describes these distributions with ideas like that of the trophic pyramid and trophic cascades.

A single intelligent species that had made a breakout to spacefaring civilization would possess a first mover advantage in distributing the life associated with its homeworld biosphere throughout the cosmos. Anywhere that that intelligence traveled in its biological form (i.e., assuming that it chose not to expand by AI virtual proxy), would involve the inclusion of a variety of related homeworld species, whether domesticated species for food and industrial materials, companion species, and even the microbiome of the intelligent species’ gut bacteria. If, further, that intelligent species coupled its exploration of the universe with a desire to distribute species of its homeworld biosphere throughout the cosmos (e.g., Claudius Gros’ Genesis Project), there would result an ecological homogeneity characterizing the entire universe.

If, on the other hand, two or more intelligent species having made a breakout to spacefaring civilization, each exploring the universe and experiencing the other as a limit to its exploration and the distribution of homeworld flora and fauna, the ecological constitution of the universe would be radically different from that contemplated above. In the event of multiple spacefaring species, multiple ecological zones would correspond to the spacefaring range of each species.

It is in the context of multiple spacefaring species that we might see something like The Wilderness Hypothesis instantiated (also cf. the Wow! Signal burst spoken word version, The Wilderness Hypothesis, as well as my post Rewilding the Cosmos Primeval), such that different intelligent species came to play different ecological roles in an intelligence-rich cosmos, with some being prey species, some predator species, some species coming together in mutualism, commensalism, or parasitism, and so on. Here the idea of a an apex predator species dominating some region of the cosmos makes sense, and the extent of the apex predator range, its rivalry with other apex predators of congruent ranges, and the survival strategies of other intelligent species lower in the cosmological trophic pyramid, would all affect the distribution of species within the cosmos.

Here the influence of an apex predator intelligent species would serve a function much like apex predators in the terrestrial biosphere, largely keeping would-be spacefaring civilizations close to their homeworld and so increasing cosmological-scale biodiversity by preventing the species of any one world from dominating the cosmos.

The Struggle for Apex Status in the Cosmos

While it is likely that the intelligent progenitor of a spacefaring civilization would be the evolutionary psychology of its place in the ecology of its homeworld to its place in the cosmos, but it is possible, at least, that a first mover in cosmological expansion, even if it did not descend from an apex predator on its homeworld, might assume this role in the cosmos. Human beings, after all, did not descend from a long line of apex predators, but transformed itself into an apex predator once it brought the resources of intelligence to hunting. Subsequently, human beings have evolved under the selection pressures that act upon hunters, and have thus been further shaped by this selection. But the deep history of human evolutionary psychology is not that of predators.

In the context of multiple spacefaring civilizations in the cosmos, a parallel process such as that which brought human beings to the apex role in the terrestrial ecosystem could act to bring another non-predatory species to the apex predator position in the cosmological tophic pyramid. And the struggle of mulitple such species over cosmological scales of time would mean that no one civilization would likely remain as the sole apex predator, but would always risk being overtaken by an ambitious civilization seeking to climb higher up the cosmological trophic pyramid.

In several posts I have discussed the possibility of what I call intelligence-rich biospheres. These posts include: