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The Star Larvae Hypothesis
Nature's Plan for Humankind
Part 1. Metabolic Metaphysics

Coincidence and Creativity in Nature: Liberal Applications of Niche Construction

Natural selection and genetic drift do not shape organisms to fit ecological niches. Organisms construct the niches that they want. From top to bottom.

Nature is full of happy coincidences, as when environments happen to suit their inhabitants.

Or, is it the inhabitants, having been worked over by natural selection and genetic drift, that are suited to their environments? Or, is it that creatures custom manufacture environments to suit themselves?

The model emerging from evolutionary biology increasingly credits organisms with the niches that they occupy, because they have conditioned the spaces around themselves and shaped them to suit themselves..

Creatures eat what is edible. They excrete what is excretable. They modify the pH of soils and water. They construct conspicuous structures, including dams, nests, burrows, and webs (let alone supercomputers and satellites). Pseudomonas syringae, a kind of bacteria, nucleates raindrops. Plants trade carbon dioxide for oxygen, modifying, or maybe regulating, the Earth's atmosphere. These environmental effects affect not only the organisms that produce them, but also those organisms' neighbors and descendants.

Biologists have been slow to acknowledge that such creative work implies much for evolution theory. Why would it take so long to acknowledge the implications? If environments select the more fit organisms and bestow upon them greater reproductive success, then altering environments—e.g., constructing niches—should skew selection pressures and thereby skew evolutionary outcomes. Why has the tradition been to dodge constructed niches when expounding evolution theory?

Maybe acknowledging the niche-constructing behaviors of creatures would seem to give the creatures agency. That is, it would seem to give species a role in steering their own evolution—along with the evolution other species that share the modified environment—and might suggest that creatures, thereby, steer their own evolution. Nonetheless, evolutionary biologists are coming to acknowledge that the fit of organisms to their environments, and vice versa, is the outcome of a feedback process, a circular casuistry. Environments accommodate their inhabitants, to greater or lesser degrees, because the inhabitants, with greater or lesser skill, construct those environments.

The Anthropic Cosmological Principle

On a scale far removed from biology, or seemingly so, sits an idea called the Anthropic Cosmological Principle. It has to do with the universe's physical constants, quantities such as the strength of gravity and the charges and masses of fundamental particles—the laws of nature, essentially. These parameters must be tuned precisely to make our kind of universe possible, our kind being one in which stars, planets, galaxies and biological organisms cohabit. If any of the values of the constants varied even slightly, then the universe would exhibit a very different character. Galaxies, atoms, and planets, let alone the complex organisms that inhabit the Earth, never would get off the ground. What's to be made of the tuning of fundamental physical laws such that it specifies a universe so accommodating to biology?

One interpretation yawns at the accommodation. After all, if the laws were other than what they are, then no one would be around to wonder about, let alone measure, the mass of the muon and other particles and so on. The presence of biological organisms requires that the laws be as they are. When researchers measure the fundamental physical constants, the existence of the researchers in the first place dictates which values they will discover, namely, those that enable the researchers to exist.

Nonetheless, if the laws of nature could have been fixed arbitrarily—if they had been left to chance—then their settling on those precisely balanced values that allow, and maybe foreordain, intelligent observers would be astronomically unlikely. But if the laws could not have been otherwise, then whatever constraint applied was conspicuously providential from the point of view of biological organisms. What, scientifically or philosophically, is to be made of the fundamental laws of physics being so accommodating is a source of ongoing debate. This point will be revisited after a consideration of certain aspects of biology.

The Gaia Hypothesis

Stepping aside from the realm of fundamental constants to something more tangible, the Earth, reveals another instance of nature accommodating biological needs. This is the situation that scientist James Lovelock characterized with his Gaia hypothesis. The hypothesis raises questions about chance/coincidence versus design/creativity in nature. Lovelock named his hypothesis after an Earth goddess, because it suggests a planetary organism. The hypothesis suggests that the model of one integrated, self-regulating metabolism—a geophysiology— might be the most useful scientific understanding of the Earth as a whole. The idea is inspired by the interlaced feedback exchanges among environments and their inhabitants that keep conditions suitable for those inhabitants. That is, a kind of thermal and chemical self-regulation keeps Earth bio-friendly. It's a peculiar thing.

Given the many hundreds of millions of years that have passed since the Earth cooled from its hot origins, the planet’s fluid environment—its atmosphere and oceans—by now should have settled into a state of chemical equilibrium. Whatever chemical reactions one would expect from the chemicals that compose the atmosphere and oceans should have run their course by now, and the atmosphere and oceans should be sitting in a state of stable chemical equilibrium, or maximum entropy.

But that is far from being the case.

The Earth is unique among the planets. Its fluid environment operates in a state of stable, long-term disequilibrium. It somehow resists the pull of entropy. The sun's ongoing input of energy to the Earth helps explain the apparent anomaly, because free energy can be channeled to keep entropy at bay. But that doesn't settle the matter (or explain why sunshine doesn’t keep entropy at bay in the atmospheres of Venus or Mars).

The Earth's stable, long-term disequilibrium is not a randomly fluctuating one. Despite volcanism, meteoric impacts, variations in solar output, and other perturbations, once complex organisms appeared on Earth, the Earth's environment never veered outside the tightly constrained parameters needed to keep complex life living. Not only is the biosphere sitting, anomalously, in a stable state removed from the expectations of equilibrium chemistry, but also, that anomalous position is in the narrow range needed to support complex life. Is it just a coincidence that the Earth maintains itself in the way needed to keep a complex biosphere humming stably, far from equilibrium?

It’s like the anthropic coincidences. Plants and animals are lucky. Everything is working in their favor. Life thrives in the peculiarly stable, far-from-equilibrium conditions of Earth, because fundamental physics and chemistry happen to coincide with the needs of biology.

But Lovelock's theory isn't about happy coincidences. It's more interesting than that. It’s about life itself functioning as a self-serving, self-preserving, homeostatic agency that operates planetwide. Lovelock proposes that biology uses feedback controls to maintain the biosphere in its bio-friendly disequilibrium. The planet remains bio-friendly, because it is a cybernetic system within which life sits at the helm.

The regulatory mechanisms involved can be staggeringly complex. As an example, Lovelock outlines the interwoven processes prospectively involved in maintaining the right oxygen level in Earth's atmosphere. Because the atmosphere loses lightweight hydrogen to space when water molecules dissociate at high altitude, leaving the water’s heavier oxygen atoms hanging in the atmosphere, the concentration of atmospheric oxygen should increase over time. If that were to happen, then life on Earth would wind up a casualty, because a slight increase in atmospheric oxygen would turn the Earth into a fireball. The regulatory processes that prevent the fireball, that keep the oxygen level constant, include photosynthesis, aerobic and anaerobic respiration, geologic burial of plant material and so on. Ostensibly abiotic processes, such as the weathering of rocks, make their contribution, but even then, with bacteria playing a role by nucleating raindrops, biology has a hand.

Lovelock suggestively characterizes what’s going on in terms that recall Richard Dawkins’ notion of an “extended phenotype” and a more recent coinage from ecological science, “niche construction.” In Gaia: A New Look at Life on Earth Lovelock comments,

“The chemical composition of the atmosphere bears no relation to the expectation of steady-state chemical equilibrium. The presence of methane, nitrous oxide, and even nitrogen in our present oxidizing atmosphere represents a violation of the rules of chemistry to be measured in tens of orders of magnitude. Disequilibria on this scale suggest that the atmosphere is not merely a biological product, but more probably a biological construction: not living, but like a cat’s fur, a bird’s feathers, or the paper of a wasp’s nest, an extension of a living system designed to maintain a chosen environment. Thus the atmospheric concentration of gases such as oxygen and ammonia is found to be kept at an optimum value from which even small departures could have disastrous consequences for life”

Lovelock goes on to observe something similar going on in the oceans. Ocean-bed tectonics and water runoff from land continue to add minerals to the oceans, including salts, but the overall salinity of the oceans remains relatively stable. Why doesn’t the ongoing addition of salt steadily increase the salinity of seawater? It remains an open question, but Lovelock proposes various direct and indirect mechanisms by which oceanic microorganisms sequester excess minerals, by creating mineral “sinks” that carry the concentrated minerals to the ocean floor for burial. Diatoms use silicon for their “skeletons” and when they die, their corpses deliver the silicon to the ocean floor. Microorganisms also contribute to the creation of temporary marshes where salt gets abandoned on land when the marsh water evaporates.

This is all to say that the atmosphere and oceans resist equilibrium and remain in states of stable disequilibrium that are conducive to complex ecosystems. They do not defy entropy for some reason that is merely fortuitous, but because the biological world, in going about its metabolic business, corrects tendencies toward increasing or decreasing levels of atmospheric gases and dissolved sea salts. In doing so, life shapes its environment and maintains it as an accommodating place in which to earn a living.

Niche Construction

Scaling down further, from the planet to local ecologies, reveals biology hard at work maintaining individual ecological niches. On this scale, environmental conditioning by organisms to make their world more hospitable is called niche construction. Niche construction theory recognizes that such behavior often affects organisms other than the constructors. Niche construction theory therefore assigns to creative behavior and its products an evolutionary significance.

Examples of niche construction range from bird nests, beaver dams, and coral reefs to soil conditioning by earthworms and bacteria. The cases are endless. But evolution theorists have tended to downplay the evolutionary significance of these effects. Now that bias is being challenged by a wider acknowledgment that when organisms shape environments, they shape selection pressures, making the environment-organism relationship, in evolutionary terms, one of circular influence. The idea complicates the theory of natural selection, with that theory's reliance on the organism being a more or less passive object of environmental selection pressures.

Researchers at the Laland Lab at the University of St. Andrews in Scotland are working to better integrate niche construction theory into evolution theory. The niche construction pages on the Laland Lab website provide a good introduction to the topic and argue for its applicability to evolutionary biology and other biological sciences: http://synergy.st-andrews.ac.uk/niche/rethinking-adaptation

Niche construction brings to evolution theory a mode of inheritance parallel to that of genetics. That added vector is ecological inheritance and it has to do with the environment in which a new generation of organisms finds itself, that environment, or ecology, itself having been shaped by previous generations of organisms. Of whatever species. Constructed niches can exert cascading ecological effects that involve not only the constructors, but also their descendants and unrelated neighbors—and their descendants and neighbors. A beaver dam alters selection pressures that can affect plant and animal species across the beaver’s habitat. Kevin Laland comments,

“Yet all living creatures, through their metabolism, their activities, and their choices, partly create and partly destroy their own, and each other’s, niches, on scales ranging from the local to the global. Organisms choose habitats and resources, construct nests, holes, burrows, webs, dams, pupil cases, and a chemical milieu, and choose, protect and provision nursery environments for their offspring. They also take energy and resources from environments, emit detritus and die in environments, and by doing all these things, modify at least some of the natural selection pressures present in their own, and in each other’s, local environments.”

Biologists Richard Dawkins and R. C. Lewontin floated precursors to the idea of niche construction and helped plant the seed of the idea in the biological sciences community. In The Extended Phenotype, Dawkins elaborates on the idea that once a creature modifies its environment then that modification constitutes an extension of the creature’s phenotype. And the result can have evolutionary consequences, but those consequences—skewed selection pressures—are limited, in the view of Dawkins, to selection concerning the genes that govern the behavior that extends the phenotype. Certain insects might gather pebbles to protect or insulate themselves, and the gathered pebbles thereby contribute to the insects’ reproductive success. But the skewed selection pressures that result concern only selection favoring those genes involved in pebble gathering. Ancillary effects are not part of the evolutionary story, according to Dawkins’ concept of the extended phenotype.

The niche construction perspective regards this view as overly conservative. Proponents of niche construction theory argue that extended phenotypes are constructed niches and can have far-reaching effects. The star larvae hypothesis regards even this view as overly conservative.

Gaia, the biosphere taken as a whole, also is a constructed niche. Like the Gaia hypothesis, niche construction theory grants agency to organisms when it comes to accounting for how well adapted they are to their environments; It is because they create environments that suit them. Gaia might be conceived of as the integrated superset of constructed niches.

The Earth’s biosphere is a constructed niche, actively regulated by its living inhabitants. That might seem to be a loose application of the concept of niche construction, but there’s one at the lower end of the spatiotemporal scale that stretches the concept further, or, perhaps, shrinks it.. Zooming in from the ecological niche to the organism and its cells reveals a finer-grained, inhabitant-driven environmental conditioning.

Morphogen Gradients

The differentiating cells that compose a developing embryo find themselves by good fortune in an environment that sees to their needs and changes its particulars to meet the needs of their descendants. The cells find themselves surrounded by other cells with which they are compatible and that they coincidentally and to greater or lesser degrees depend upon to help maintain the hospitality of their shared environment, which is the developing embryo. It’s a coincidence that the cells happen to provide one another with a chemical environment that enables them to thrive and cooperate in their ontogenetic project.

Clearly this is not what’s going on. It’s not a matter of luck. The cells make their environment hospitable by actively regulating it. That seems at least to be nearer the case than the prospect of every complex organism’s development hanging on reliable coincidences that happen to favor a predictable differentiation and organization of cells.

Cells differentiating in an embryo release morphogens, molecules that trigger patterns of genetic expression and repression in receptive neighboring cells. Diffusion gradients, tapering from points of morphogen dispersal to distant regions of the embryo, intersecting this way and that, set up a grid of morphogen concentration levels to which cells at various locations in the embryo, and at various stages of its development, are sensitive. And those cells, in turn, release their own morphogens, and thereby construct accommodating niches for their fellows and for their descendants, in a dynamic chemical feedback system, as needed to maintain favorable conditions in the embryo such that it develops into a functioning member of its species. The issuance of morphogens and the ensuing concentration gradients constitute an instance of niche construction during ontogeny. The cells shape their environment and that of their neighbors, thereby creating an ecology that all their descendant cells inherit. By extension, the many modes of cell signaling also can be seen as modes of niche construction.

Is this Universe a Constructed Niche?

Turning back, now, from biology to nature’s physical constants, it turns out that the constants might not be so constant. They might evolve. And develop.

Read again from the top of this page about the anthropic coincidences and how the specificity of the physics of this universe aligns precisely with the needs of biological organisms. If there is variability built into the laws of nature, then the laws being specifically conducive to life, at least during this stage in the life of the universe, makes the whole universe resemble a constructed niche. Physicist Lee Smolin, in Time Reborn, cites examples of twentieth-century physicists who pondered the prospect of the laws of nature evolving. He quotes the prominent physicist Paul Dirac:

"At the beginning of time the laws of Nature were probably very different from what they are now. Thus, we should consider the laws of Nature as continually changing with the epoch, instead of as holding uniformly throughout space-time."

Smolin continues,

"John Archibald Wheeler, one of the great American physicists, also imagined that laws evolved. He proposed that the Big Bang was one of a series of events in which the laws of physics were reprocessed. He also wrote, ‘There is no law except the law that there is no law.’ Even Richard Feynman, another of the great American physicists and Wheeler's student, once mused in an interview: ‘The only field which has not admitted any evolutionary question is physics. Here are the laws, we say, but how did they get that way, in time? . . . So, it might turn out that they are not the same [laws] all the time and that there is a historical, evolutionary, question.’"

Smolin adds his own challenge to the doctrine of timeless natural laws. If the physical universe contains everything, the existence of other universes notwithstanding, he argues, then the laws of nature, too, must be part of the universe and not mathematically described facts that persist on their own in a kind of Platonic dimension outside of time. And, being part of this universe, the laws of nature must be subject to change. He proposes, “[T]here should be nothing in the universe that acts on other things without itself being acted upon. All influences or forces should be mutual. We can call this the principle of no unreciprocated actions.”

He cites as an application of this principle Einstein’s general relativity. Unlike Newton’s model of an unchanging, absolute space in which objects are deployed, Einstein’s model includes changes in space itself due to the objects in it. The masses of the objects shape the surrounding space, and that shaped space in turn influences the motions of the objects. If the laws of nature determine the character of the universe, then that character in turn should influence the laws. Smolin’s case includes additional points, but this example illustrates his contention.

The laws of nature, proposes Smolin, “evolve.” But he identifies only one avenue of change that should be called evolution (or, phylogeny). Another avenue of change that he identifies would rightly be called development (or, ontogeny).

The first process derives from the theory of cosmological natural selection, which Smolin describes in his previous book, The Life of the Cosmos. The theory argues that black holes function as a universe’s reproductive organs, each black hole being responsible for the birthing of a new universe, an addition of one to the population of universes that physicists call the multiverse. Universes with laws of nature that produce lots of black holes give birth to lots of baby universes, each of which inherits natural laws from its parents. More fertile universes, those that enjoy greater reproductive success, skew the phenotypes of subsequent generations, as in biological evolution. But the system of inheritance includes enough indeterminacy to allow the laws to bend slightly from one generation to the next. This variation gives natural selection something to chew on. Smolin comments:

"Cosmological natural selection thus offers a genuine explanation of why the parameters of the Standard Model appear to be tuned for a universe that is filled with long-lived stars that over time have enriched the universe with carbon, oxygen, and other elements needed for the chemical complexity our universe is blessed with. The parameters whose values are thus to a greater or lesser extent explained include the masses of the proton, neutron, electron, and electron neutrino, and the strengths of the four forces. There's a bonus: While the explanation involves maximizing the production of black holes, a consequence is to make the universe hospitable to life."

Later he repeats that curious final observation:

"Remarkably, there are many commonalities in the lists of features that make a world hospitable to life and highly productive of black holes."

When a scientific observation is "remarkable," presumably being worth remarking about because it is no obvious outcome of the theory under consideration, or when observation reveals an unexpected "bonus," (presumably something coincidentally fortuitous) such anomalies should stand out to the interested observer as indicators of something interesting. They suggest that the universe has thrown some theory a curve ball. But the coincidence of the laws for black holes and biological life being the same set of laws is no coincidence at all. It dovetails neatly with the star larvae hypothesis, because the hypothesis takes biological life and black holes to be stages of the same life cycle, the stellar life cycle. They constitute, respectively, the larval stage and a terminal stage of that cycle. Through the lens of the hypothesis, the handy reliance of space scientists on the vocabulary of biology appears to be more than a convention of convenience. Finding in biology a reservoir of metaphors, space scientists tell us that stars are born, mature through predictable stages, and die. Smolin also taps the reservoir; again from Time Reborn:

"The mix of kinds of universes [in the multiverse] will continually change over time, as new ways to be fertile are discovered by trial and error. This is the way biology works. There are no maximally fit species that persist forever; rather, every era in the history of life is characterized by a different mix of species, all relatively fit. Life never reaches an equilibrium, or ideal state; it is ever evolving. Similarly, whatever laws are typical in the population of universes will change in time, as the population evolves."

A key point in the biological model of cosmology is that universes not only evolve through generations, as in Smolin’s model, but individual universes also change internally, becoming more complex, resisting the pull of entropy, like developing organisms, a distinct, second mode of change. (Although, in keeping with the star larvae hypothesis' interpretation of biological evolution as a process of development, the hypothesis is tempted to see even in the evolution of universes an instance of development.) Smolin explains: "Even now, more than 13 billion years after the Big Bang, our universe is not in equilibrium. [. . . .] The question of why the universe is interesting and appears to be getting more so is akin to the question of why the second law of thermodynamics has yet to act to randomize the universe into thermal equilibrium, in spite of billions of years of apparent opportunity to do just that."

And later: "[W]e can see almost back to the Big Bang and out a corresponding 13 billion light-years, and we see no evidence for our region of the universe being a low-entropy fluctuation in a static world in equilibrium. We see instead a universe evolving in time, with structure on every scale developing as the universe expands."

This observation—i.e., that the universe continues to develop—parallels Lovelock’s regarding the Earth’s refusal to settle into chemical equilibrium. Universes would seem to be organisms akin to Gaia. Universes develop increasingly complex internal structures and processes and evolve through generations and maintain themselves in states of stable disequilibria. The laws of nature fitting so precisely the needs of black holes and of biological organisms alike makes the universe look like another instance of niche construction.

It's not that the laws or the values of the fundamental constants coincidentally allow black holes to condense and biological organisms to sprout. It's that this fortunate circumstance might have been engineered.

Borrowing again from biology, it could be supposed that all universes inherit more or less the same laws—more or less the same "genome"—and that potential expressions of those laws—that is, the possible phenotypes of universes—still could vary dramatically, depending on "epigenetic" controls that would tend to preserve laws, though with wiggle room from parent to offspring universe, and would regulate expression of the laws within a universe as it develops from newborn to juvenile to adult and through senescence to death. At least, that’s how biology works.

In any case, natural law, being potentially a component of a constructed niche, might be modifiable by organisms going about their metabolic business. The current values of the laws might have been set by ancestors of the universe's current inhabitants or by inhabitants of previous universes. If natural laws are components of created niches (universes), then they must be subject to change, as Smolin contends.

If that is the case, then biological life enjoys a generous ecological inheritance that extends down to the most fundamental laws of physics. Wherever in nature conditions accommodate the long-term needs of complex organisms, it might be a good bet that niche construction and development are the more determinative causal mechanisms, relative to, say, natural selection and genetic drift. The environment/organism distinction becomes difficult to maintain in this model. A discrete unit of concern cannot be extracted from the organism/environment dyad.

Especially if creatures create their niches, then a niche is defined meaningfully in relationship to its inhabitants. Their metabolisms and creative activities condition the context that their future generations inherit. All terrestrial organisms inherit the accommodating physical laws of the universe. And the accommodating chemical makeup of the Earth. And the accommodating ecologies. And each cell in a complex organism inherits the accommodating body within which it operates and which it helps to condition for future generations by making its metabolic contribution.

Would cosmologists be lost without the language of biology from which to draw metaphors?

Would biologists be lost with out the language of teleology from which to draw metaphors?

NEXT > Teleology, The Forms Of Function

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