Dorion Sagan Demands That We Make Science an Adventure AgainS

In a terrific new book out today, Cosmic Apprentice, Dorion Sagan argues that it's time we reboot the scientific enterprise — by using philosophy.

Sagan is the son of famed scientists Carl Sagan and Lynn Margulis, so he grew up surrounded by speculative ideas about both cosmology and biology — later, he also collaborated on a few books with Margulis. He pays homage to his famous parents here, including memories of his childhood alongside serious scientific and philosophical speculation. It's incredible, and we've got the whole first chapter for you to read.

Chapter One: The Human Is More Than Human: Interspecies Communities and the New Facts of Life

Motley Crews

“This universe,” says the physicist Richard Feynman, “just goes on, with its edge as unknown as the bottom of the bottomless sea . . . just as mysterious, just as awe-inspiring, and just as incomplete as the poetic pictures that came before. But see that the imagination of nature is far, far greater than the imagination of man. No one who did not have some inkling of this through observation could ever have imagined such a marvel as nature is.”

Well, it is to this universe that I want to turn again, and to a specific part of it. I want to turn to life, and within that part a fascinating subsystem, the one in which, of course, we are most interested: ourselves. Yet there is a paradox that precisely the nonanthropic, the nonhuman, the posthuman, the transhuman, the more-than-human, the animal has recently captivated the interest of anthropologists, whose ostensible focus is precisely anthropos, the human.

It might be called the paradox of exclusion, or even the return of the repressed. We see it in quantum mechanics, in the recognition of the role of, or the need to take account of, the experimental apparatus, the experimenter’s decisions (what Karen Barad calls “the agential cut”) in making a measurement. We see it in thermodynamics, where descriptions of behavior in thermally sealed boxes were boldly extrapolated to the whole universe, thus predicted to undergo a “heat death,” the running out of energy. And we see it in genocentric biology, where Max Delbruck simplified the study of life by studying nonmetabolizing viruses of bacteria, so-called bacteriophages, to home in on the genetic mechanism. In each case, simplifying assumptions or experimental designs blocking out most of the world reveal not only natural processes but are hastily applied beyond the limited arena in which they were developed. We are stressed by what is repressed. Anthropology—the study of human beings—obeys this same logic of the return of the ghost of what was excluded, in this case all the systems, living and nonliving, which make our kind possible.

But I think there is another reason, more specific to anthropology, for why “the nonhuman” is pressing. There are twice as many people on the planet today as when I was born. This is unsustainable. At this rate there will be 6.5 trillion of us by the year 2525—and 13.312 quadrillion by the year 3000, just around the corner in geological time.

Nicholas of Cusa said the universe is a sphere whose center is everywhere and circumference is nowhere. I don’t know about you, but that sounds about right. We love to think we are special, but the history of science suggests otherwise. Now the anthropos, the human itself, is coming under pressure.

Imagine an alien penetrated the roof of this building, materializing from a scintillating beam of blue to train a cell gun on you. He, she, or it pulls the trigger. “You” begin to dematerialize. The beam annihilates every human cell in your body. Still, your form, like the recognizable smile of the Cheshire Cat, would persist:

What would remain would be a ghostly image, the skin outlined by a shimmer of bacteria, fungi, round worms, pinworms and various other microbial inhabitants. The gut would appear as a densely packed tube of anaerobic and aerobic bacteria, yeasts, and other microorganisms. Could one look in more detail, viruses of hundreds of kinds would be apparent throughout all tissues. We are far from unique. Any animal or plant would prove to be a similar seething zoo of microbes.

Life deals in such mixed cultures. It has been working with crowds for billions of years. Most of the DNA of the estimated 100 quadrillion cells in our bodies is not “ours” but belongs to cohabiting bacteria.

Great fleas have little fleas upon their backs to bite ’em,

And little fleas have lesser fleas, and so ad infinitum.

And the great fleas themselves, in turn, have greater fleas to go on;

While these again have greater still, and greater still, and so on.

—Augustus de Morgan, after Jonathan Swift

Hypersex and Frenemies

Ten percent of our dry weight is bacteria, but there are ten of “their” cells in our body for every one of “ours,” and we cannot make vitamins K or B12 without them. The maverick Russian geochemist Vladimir Vernadsky thought of life as an impure, colloidal form of water. What we call “human” is also impure, laced with germs. We have met the frenemy, and it is us.

But before leaving this point of the pointillist composition that is our Being made of beings, please notice that even those cells that do not swarm in our guts, on our skin, coming and going, invading pathogenically or aiding probiotically—please notice that even these very centralanimal cells, the differentiated masses of lung, skin, brain, pancreas, placental, and other would be strictly human tissues that belong to our body proper—even they are infiltrated, adulterated, and packed with Lilliputian others. The mitochondria, for example, that reproduce in your muscles when you work out come from bacteria.

We come messily from a motley. Indeed, we literally come from messmates and morphed diseases, organisms that ate and did not digest one another, and organisms that infected one another and killed each other and formed biochemical truces and merged. About forty genes are shared exclusively by humans and bacteria, suggesting they have been incorporated specifically into our genome. Our guts are packed with bacteria whose aggregate microbiogenome has about 150 times more genes than “we” do, 3.3 million to our 23,000. But they, though they come and go more easily than the rest of us, changing our mood and food, are also us. The immune system itself seems to be an evolved metasystem, a convoluted go-between, marshaling regulation and inflammation, and making sure that our animal cells and the rest of us—our bacteria and archaea—take it easy on each other.

Hypersex is a provisional name for the commingling of organisms that meet, eat, engulf, invade, trade genes, acquire genomes, and sometimes permanently merge. Life displays mad hospitality. The Korean biologist Kwang Jeon of the University of Tennessee received in the 1970s a batch of amoebas infected with a deadly bacterial strain. Most died. In a set of careful experiments after culturing the survivor amoebas for several generations, he found that the survivors, with fewer bacteria per cell, could no longer live without their infection. Deprived of their new friends and former enemies, the nuclei would not function without micro-injections of bacteria into the cytoplasm. The sickness had become the cure; the pathogens had become organelles; the last had become the first.

Had Jeon, who was a Christian, witnessed speciation in the laboratory? It seems so. But it was not gradual, as neo-Darwinism predicts. It was near-instantaneous, the result not of mutations accumulating in a lineage but of transformative parasitism.

Symbiogenetics

Peculiar behavior, you say? Not really. Considering that life has been growing on Earth for some 3.8 billion years, it is not surprising that life has grown into itself, eaten itself, and merged with itself. Crowd control has long been an issue. Radical solutions have long been the norm. In 2006 researchers at Texas A&M University and the University of Glasgow Veterinary School in Scotland reported to the Proceedings of the National Academy of Sciences that endogenous retroviruses called enJSRVs are essential for attachment of the placenta and therefore pregnancy in sheep.

Like bacteria, viruses “R” us: They have moved into our genomes. Viral structural proteins have been “hijacked” and integrated into mammal reproductive tissues, immune systems, and brains. Some retroviruses disable receptors that lead to infection by other retroviruses. There is no racial, let alone genetic, purity in life. At bottom we are part virus, the offspring not just of our parents but of promiscuous pieces of DNA and RNA. The road to humanity is paved with genetic indiscretions and transgressions, no less than sheep would not be sheep without their acquired enJSRV.

The symbiosis expert Margaret McFall-Ngai asked a roomful of doctors what it meant for our marine ancestors to be surrounded by all those germs—about a hundred million cells per liter. They had no answer, but she told them: She has proposed that the immune system evolved not to eliminate pathogens but to select for symbionts in the microbe-packed waters of our metazoan ancestors.9 The immune system in its origin may thus be more like an employment agency, recruiting desired species, than like a national security state, recognizing and refusing entry to guard the fake purity of the Self.

Today it is widely recognized that the cells of animals were once a wild party of two if not three ancient beings: the oxygen-poisoned archaeon host, the oxygen-using bacteria that became mitochondria, and perhaps wildly squirming spirochetes, which abound in anaerobic environments. These wrigglers often penetrate their fellows, which have no immune systems. They feed at the edges, becoming snaky motors propelling their brethren, or take up residence inside them, wiggling happily ever after.

According to my mother, who’s been right before,1 ancient bacterial symbioses gave our ancestors the intracellular motility abilities we see in mitosis, and in the growth of undulating appendages. The creation of new symbioses by mergers on a crowded planet is called symbiogenesis. And we might call all aspects of its study “symbiogenetics”—the science of normative symbioses, the word commanding respect because of its apparent coinage from genetics; in fact, I derived it directly from symbiogenesis, though the connotation is a good one. Although this type of evolution sounds bizarre—a monstrous breach of Platonic etiquette in favor of polymorphous perversity—it is now confirmed by genetic evidence, taught in textbooks. It is a fact, or what the French philosopher of science Bruno Latour and the Belgian physicist-turned-philosopher Isabelle Stengers, not putting too fine a point on it, would call a factish. Nonetheless, although symbiogenesis—the evolution of new species by symbiosis—is now recognized, it is still treated as marginal, applicable to our remote ancestors but not relevant to present-day core evolutionary processes.

This is debatable. We are crisscrossed and cohabited by stranger beings, intimate visitors who affect our behavior, appreciate our warmth, and are in no rush to leave. Like all visible life forms, we are composites. Near unconditional hospitality is necessary when we consider the sick factish that most of the human genome may be viral DNA. Lactating women transfer their six hundred species of bacteria to their babies, as well as oligosaccharides their babies cannot digest but that feed certain bacteria. Bruce Sterling writes science fiction about humans engineered not to have any bacteria, but experiments with real mice deprived of their bacteria developed abnormal levels of immune system cells called invariant natural killer T cells that turned on their hosts, causing higher levels of inflammation, asthma, and inflammatory bowel disease. Although we are not mice, human studies show that early exposure to antibiotics is associated with asthma. The idea that we need to be pure and free of microbes to be healthy is as medically misguided as eugenicist dreams of triumph through racial homogeneity. Hundreds of species of fungi live in mammal guts despite our immune systems. Indeed, scientists found that immune cells produce dectin-1, a protein that feeds skin fungi of mice; when they engineered the mice not to produce it, the mice experienced tissue damage from excess inflammation. It appears that our immune systems are designed not just to get rid of dangerous strangers but to entice needed others. No notion so disrupts the Pasteurian meme of health through biotic purity as the interest recently generated in fecal transplants, which have been declared safe in treating overgrowth of Clostridium dificile in patients needing to restore gut biota devastated from antibiotics, and are being investigated for the treatment of obesity. Another new medical approach is to develop skin creams that feed beneficial bacteria, warding off pathogens like Staphylococcus aureus.

Of course these are medical avenues developing within a disease industrial complex that has long been in an emergency mode and makes its money from treatments. But symbiotic partnerships have the possibility not just to restore health but to improve it and alter us, to evolve us into new forms. I can envision future people with harmless luminous patches of bacteria, like tattoos but glowing in the dark, perhaps responding to mood or flashing like fireflies.

Some partnerships are fantastic. Luminous bacteria cram together to provide various marine animals with organs to light their way; deep-sea anglerfish females even use their shiny bacteria lights as lures to catch other fish. Luminescent bacteria, of the species Vibrio fischeri, provide the bobtailed squid, Euprymna scolopes, a nocturnal animal that feeds in the moonlight, so-called counterillumination: it projects light downward from its light organ, so it doesn’t show up as a tasty morsel outlined in silhouette for hungry predatory fish below.

Nestled within the chromosomes of some parasitic wasps lie bacteria. Multiple insect species transform because of Wolbachia bacteria. The genus is nearly ubiquitous in insect tissues. Too big to fit within the sperm of insects, infective Wolbachia can confer parthenogenesis on insect populations, that is, transform a population with two genders into one that is all females, this of course to the advantage of the “selfish” bacteria, as the sperm bottleneck impedes their propagation. By disabling the gender-bending bacteria, antibiotics can make separate species of jewel wasps interbreed again. More bizarre than the space aliens we imagine abducting and toying with us on their saucers, these gender-changing bacteria bring in suites of genes for metabolic and reproductive features as they establish symbioses, often permanent, in arthropods.

Weird Dalliances and Unexpected Speciations

In an unexpected textbook example of speciation, the Columbia University geneticist Theodosius Dobzhansky selected fruit flies for their ability to withstand heat and cold. Dobzhansky found that after two years the heat-adapted flies could no longer successfully fertilize cold-living ones. The two separated populations of Drosophila paulistorium now conformed to the traditional zoological definition of new animal species. They had been reproductively and geographically isolated, and were now only able to breed with their own kind.

However, Wolfgang Miller of the University of Vienna Medical School, Austria, later found that the “cold-fertile fly population” had retained a symbiont widely distributed in certain tissues, whereas the “hot-fertile flies” had been “cured” of the symbiont. In fact, Dobzhansky’s flies evolved as a result of the presence or absence of “mycoplasma,” now recognized to be in the aforementioned genus of Wolbachia. In other words, the presence or absence of a bacterium, not neo-Darwinism’s much-vaunted but still theoretical gradual accumulation of random genetic variations, correlated with what is, besides the Jeon experiments, perhaps the only real-time observed example of a speciation event.

Humanity’s discovery of and battle with pathogenic microbial strains has misled us to think that microbes are generally extraneous to our bodies and health. But increasingly scientists are realizing that we have, we in part are, an adaptive microbiome, the endogenous collection of often “smart” microbes that is not only negatively connected to sickness but positively correlated to warding off obesity, asthma, allergies, and other maladies. Tel Aviv University’s Eugene Rosenberg found that Drosophila pseudoobscura fruit flies would mate only with others on the same diet; antibiotics removed their dietary pickiness, leading to promiscuity and suggesting that possession of specific gut microbes can be like membership in a special club, leading to selective mating and ultimately speciation. And it is likely not just insects. Our symbiotic bacteria are connected to digestion, sense of smell, immunity, and other aspects of physiology. Prokaryotes are part of the hologenome; they are not just hangers-on but genetic actors.

Such are the new facts—factishes—of life. As genes are not selves, the notion of the selfish gene remains a trope. Selves are materially recursive beings with sentience, and the minimum self seems to be a cell. Because life is an open thermodynamic system, as well as an open informational one, genomic transfer is rampant.

Leaflike green slugs (recently shown to manufacture chlorophyll themselves) and underwater snails with rows of green plastids feeding them show how plants and animals can merge. Convoluta roscoffensis does not eat but burrows under the sand of the beaches of Brittany out of harm’s way when the surf pounds (or a research scientist stomps his wading boots); when the danger passes, the animated algae, the green worms, then reemerge into the sunlight. The “planimal” is fed by the green building of its body, the living architecture that it gardens and which feeds it from within.

It seems unlikely that any cosmic deity arranged for the partners that are C. roscoffensis to come together, but they did, partly of their own accord, and they probably would have looked odd anyway on Noah’s Ark.

Identifiable new behaviors, combined skills and physiologies, and even multigenome personalities also affect us. Human gut microbiota are not simply hangers-on but influence the timing of maturation of our intestinal cells, our internal nutrient supplies and distribution, our blood vessel growth, our immune systems, and the levels of cholesterol and other lipids in our blood. They also—partly because of the presence of neurons in the mammalian intestinal tract, and the communication between gut and brain—influence human mood. Lab work with Campylobacter jejuni shows that this bacterium increases anxiety in mice, whereas the soil bacterium Mycobacterium vaccae inside them cheers them up. In people it has been suggested that yogurt with live cultures, for example with bifidobacteria, improves our sense of well-being.

Toxo

Toxoplasma gondii is a protist notorious for infecting pregnant mothers who may contract it from kitty litter. From the mother Toxoplasma moves to the fetus, often devouring it and leading to a miscarriage. Toxoplasma gondii sexually reproduces in bodies of members of the Felidae family, notably house cats. But mice, usually afraid of cats, lose their fear when their brains become infected with Toxoplasma. Also, and curiously, they become sexually attracted to feline urine.

Toxoplasma also infects large numbers of humans. Even though a possessor of Toxo may not know it’s there, he or she can be affected by it. Toxoplasma infection in men correlates with enhanced risk taking and jealousy. An index of the risk-taking behavior is provided by the fact that males in car and motorcycle accidents are more likely to test Toxoplasma-positive. Toxo-men are more likely to be unfriendly, unsociable, and withdrawn. Even if bereft of obvious symptoms, men who carry Toxoplasma are less likely, relative to controls, to be found attractive to women.

Women are another story. Women with Toxoplasma are more likely to be judged outgoing, friendly, and conscientious—and promiscuous. There is, of course, the complication of the stereotype of the woman who lives alone with all the cats. The caricature of such a woman is not of someone outgoing. Perhaps Toxo’s effects alter with age.

However confounding, Toxo’s effects seem real. Toxoplasma makes enzymes (tyrosine hydroxylase, phenylalanine hydroxylase) that alter brain levels of the neurotransmitter dopamine. Dopamine is a neurotransmitter involved in attention, sociability, and sleep. Cocaine and amphetamines work in large part by blocking the reuptake of dopamine in the brain. Dysfunctional dopamine regulation is theorized to be linked to schizophrenia, and several antipsychotic drugs target dopamine receptors. Up to one-third of the world population is thought to be infected with Toxo, with an estimated infection rate of almost 90 percent in France—a result perhaps of their love of rare beef, steak tartare or saignant, “bleeding.” More alarmingly still, the Czech scientist Jaroslav Flegr found via MRI scans that twelve of forty-four schizophrenia patients showed significant shrinkage of the cerebral cortex, but that the reduction in gray matter of the schizophrenics was almost completely correlated with those who tested positive for T. gondii. Toxo, accounting for a range of effects and affects from increased sexual attractiveness and feelings of well-being to full-on mental dysfunction, appears to be a facultative part of our more-than-human hologenome.

We have other “inner aliens.” Candida albicans is the yeast fungus that causes vaginal infections and perlèche, a cracking at the corners of the lips. It thrives on easily digestible sugars and carbohydrates such as those found in beer, wine, cracker crumbs, and confections. It was perhaps spread among the wine-drinking revelers of Provence, troubadours who sang and jested, and who may have used makeup as a way to cover cracked lips that literally hurt when they smiled.

Spirochetes are a stranger case still. Disease species cause Lyme disease and syphilis, and perhaps other conditions. Spirochetes can go into hiding and form “round bodies,” becoming virtually undetectable in cells. Friedrich Nietzsche and others are thought to have been infected by syphilis, whose “tertiary stage” is sometimes marked by a strange clarity of expression and artistic genius as well as madness.

Alfred North Whitehead on Facts

I have talked about how the “facts” of symbiogenesis can in some sense be considered superior to the theory of neo-Darwinism. But since I am speaking about scientific facts to anthropologists,19 I should probably be careful, as there is always the possibility that I am projecting cultural ideas onto the data and that all that we see or seem is but a culturally refracted dream.

According to Alfred North Whitehead, science is the bastard offspring of “irreducible and stubborn facts” (a phrase he took from William James in a letter to his brother, Henry) and the Greek genius for lucid theorizing. Whitehead argues that, far from mental gymnastics, an “anti-intellectualist” strain was crucial for science’s development—to protect it from the insular hyperconceptualization of mere academic thought.

Science had to move away from the mannerist overdeveloped rational architecture of philosophy. While the Greeks had developed a remarkable ability to think boldly and clearly, and proceed through precise logic, the medieval scholastics, following Aristotle, expanded reason into a self-perpetuating empire out of touch with the real world. And the antidote was not more thinking but engagement with the real world. Of course, for natural science, engagement did not mean observation of other people, their thoughts or practices, but rather of things and organisms.

Whitehead traces this antischolastic attentiveness, which first developed among some Europeans but belongs to anyone who will have it, in part to, of all things, Greek tragedy—whose essence he says is “not unhappiness [but] the remorseless working of things. This inevitableness of destiny . . . This remorseless inevitableness,” which in human dramas “involves unhappiness” but which “pervades scientific thought.” In short, for Whitehead the tragic realm of cause and effect has, if not a happy ending, a promising development: the development of modern science.

Closely observed by attention to facts, the inner workings of fate become reformulated as the laws of physics.

Interestingly, the Greeks—indeed the same Greek, Empedocles—came up with both symbiogenesis and natural selection thousands of years before Darwin. Empedocles had this great idea: In prehistory, organs, on their own, roamed the earth and recombined with one another. In other words, they symbiotically merged and were naturally selected. Those that persisted made copies of themselves, messily evolving.

Although Aristotle dismissed Empedocles because his mixed beings suggested irrational Greek myths, and Darwin dismissed Aristotle because Aristotle lumped natural selection with Empedocles, in retrospect Empedoclean biology looks good. If you substitute cells for organs, Empedocles intuited both natural selection and symbiogenesis.

Alas, he did not engage the empirical. To Aristotle, the wacky misbegotten organs that arose on their own and coalesced to make bodies, the less fit ones dying out, must have smacked of passé myth, the mating of Olympians and humans, chimeras and immortals. For Aristotle, Empedocles’s Dionysian imagination must have seemed a return to chaos, with no respect for observation or classification. The fifth century BCE philosopher of Acragas (now Sicily) was loopy. And for Darwin, who knew Aristotle was aware of natural selection because he mentioned it dismissively in connection with Empedocles, both Empedocles and Aristotle were wrong.

Yet as the spiral of science turns, what was once recognized as myth sometimes becomes re-cognized as science. This is the case with symbiogenesis. Strong evidence exists that all eukaryotes evolved suddenly by symbiosis, and that many other organisms such as lichens, which combine fungi and algae or fungi and cyanobacteria, did also. We speak of brotherhood, but maybe we should speak of “otherhood.” Others come together in aggregates of expanded energy use, economies of scale, and diverse assemblages where combined skills and redundancies prefigure additional developments. Together mingling beings find energy and the substances they need to live. Corals reefs require photosynthetic symbionts. “White ants,” or termites, cannot digest wood without the living hordes in their guts whose visualization Joseph Leidy compared to the outpouring of a “crowded meeting-house.” Cows, “four-legged methane tanks,” collectively add enough of that gas, unstable in the presence of oxygen, into the atmosphere that aliens, outfitted with spectroscopic devices, might be able to tell that there was life on this planet from the presence of microbially produced methane alone. And that’s no bull, though it’s close, literally.

It is hilarious to contemplate that the methanogens releasing gas in the specialized symbiotic cow stomachs called rumens could signal—with no help from humans—the presence of complex life on this planet. But this point that the archaean nonequilibrium chemistry of our atmosphere could serve as a beacon to aliens is serious, too. And it serves as a nice segue into related facts of life I want to talk about now.

Sentient Flames

Let me turn now briefly to what I consider another evidence-based discourse, a new set of life—and death—facts that may be even less well-known to you than symbiosis but which I consider equally important to understanding life.

I don’t think it’s possible to understand life without understanding the role of energy. Life is a complex thermodynamic system. Like a whirlpool or flame, the shape alone stays stable as energy is used and matter is cycled. It absolutely depends on the energy and matter. Deprive a storm system of its atmospheric pressure gradient, an autocatalytic chemical reaction of its chemical gradient, or convection of its temperature gradient, and these disappear: their form is dependent on their function—not necessarily their only function, but their basic one. And the same is, startlingly, true of life: if you deprive cyanobacteria or purple sulfur bacteria or plants of their solar energy gradient, or animals of their food-oxygen gradient, they disappear. The big difference with life is that it has found a way, via the recursive DNA-RNA-protein system, to restart the flame.

It is a thermodynamic fallacy that we are destined to die because of wear and tear and inevitable entropic dissolution connected to thermodynamics’ second law. In fact, life’s signal operation, as well you know, is to resist normal wear and tear. While writing this essay I saw a little kid’s face light up when his parents pointed at a Starbucks and pronounced the magic word, “cookie.” He recognized that sugar gradient much as a bacterium swimming toward sweetness or a sunflower following the light. Of course he is much more evolved than a bacterium or a sunflower: He is human. More to the point, taking a break from writing this essay, in the shower, I rubbed my eye and it swelled and reddened something awful. “Miraculously,” however, it restored itself.

Finding food to support its body and using energy to repair itself, which occurs even at the DNA level, are typical operations of life. But what is life doing in its cosmic context? I would argue, and have, that the metabolic essence of life is to degrade gradients. Inanimate complex systems do this, but staying alive prolongs the process. I consider this a lucid, Greek-style idea. And there are facts to back it up.

Apoptosis, telomerase-based limits on cell divisions, and sugar- and insulin-mediated genetic mechanisms ensure aging-unto-death in most familiar species. But locusts, mayflies, and other organisms that “come unglued” (experience multiple failure of organs), dying within hours of reproduction, contrast greatly with long-lived ones like sharks, lobsters, and some turtles, not known to age. (Sharks, who often devour their twins in utero, may not need to die, as they are exposed to so many death threats.)

That aging is under genetic control is attested to by the difference between Pacific and Atlantic salmon, the latter of which return upstream for another bout of egg laying. The energy connection here is that populations that grow too rapidly without moderating their growth run the risk of being wiped out by famines and epidemics. Death by aging, in other words, is not an accident but an adaptation. The important datum that near-starvation is the surest life-span extender in organisms as distant as apes and yeast (evolutionarily separated by some seven hundred million years) suggests that hunger acts as a signal to slow down aging programs, thereby increasing the chances of population and species-level survival. The modulation of aging in the face of environmental signals of scarcity is an example of physiological prudence among cells, and compares favorably with conscious human attempts to moderate population growth.

In addition to the seeming genetic fetters on unrestricted growth in our own bodies, and in populations of aging animals, consider the actual work done by plants. We like to think our symbol making and technology make us superior, but plants are metabolically superior in that they can derive energy from oxygen, which they do at night when sunlight is not available as a source of energy. They can switch-hit like this because they also incorporate those former respiring bacteria, the mitochondria, into their cells along with the plastids, which we never got, making us worry about where to get the next meal.

And plants are far from inert. The average condensation and precipitation from soil and leaves in midlatitudes during the summer is about six millimeters per hectare. This production of latent heat via evaporation off of leaves is the energetic equivalent of some fifteen tons of dynamite per hectare. Rainstorms are far more energetic. Seeded by evapotranspiration from trees, rainstorms release the equivalent of many megatons of dynamite. But they do it stably. Competing with one another for access to the light that drives their evapotranspiration, trees disperse more energy more steadily than we do even with all our technology.

We think we are smarter, but in the long term we haven’t proved ourselves to be. Indeed, we may be heating up the planet, which is a clear symptom of dysfunction in complex systems. Think of your laptop, overheating. Natural complex systems use energy and dissipate it elegantly and have learned to do so in stable ways over millions of years of evolutionary time. It is true that we are Promethean, gifted in our ability to locate and exploit energy gradients. It even happens in our own bodies, whose brains use 40 percent of our blood sugar to spin forth fancies of variable value. But the long-term thinking we pride ourselves on is not in evidence when you consider thermal satellite evidence that rainforests are the most efficient coolers of the planet. These biodiverse collectives naturally use energy, but they dissipate it away from their surface, and do so sustainably.

In Alien Ocean: Anthropological Voyages in Microbial Seas, Stefan Helmreich writes: “At the conclusion of The Order of Things, Foucault, in a phrasing that evokes Rachel Carson’s description of the seashore world, suggested that man may someday ‘be erased, like a face drawn in sand at the edge of the sea.’ He did not mean,” he adds, “that humanity might be wiped out by oceanic inundation—though such a literal reading is freshly thinkable . . . in the wake of the Indian Ocean tsunami of 2004, 2005’s Hurricane Katrina, and growing evidence of global warming. Rather, Foucault speculated that the human—that biological, language-bearing, laboring figure theorized by human sciences ranging from anatomy to anthropology to political economy—might not endure forever, just as archangels, warlocks, and savages are no longer so thick on the ground of our social imagination as once they were, and just as race as a biological category now wobbles between phantom and Frankenstein as it has been set afloat in a sea of genes.”

I believe anthropology’s new engagement with the nonhuman may be another example of “the return of the scientific repressed,” but I believe it also represents increasing pressure on us to become more integrated into more biodiverse, energetically stable ecosystems. Populations tend to be most numerous in the generations prior to their collapse. Stem cells and pioneer species spread rapidly but become integrated in slower-growing adult organisms and ecosystems that optimize and sustain energy use. In this light, humanity as a whole seems to be ending the insular rapid-growth phase typical of immature thermodynamic living systems. This view provides a possible new positive interpretation of Franz Kafka’s witty lament, “There is hope, but not for us.”

Excerpted from Cosmic Apprentice, (c) Dorion Sagan, University of Minnesota Press.