I want to hold a mirror up to 2025. Fold the century in half like a sheet of paper, and then half again, bring today face-to-face with fifty years ago. 1975 and 2025 resonate in several ways. But I’m interested in one, apparently minor reflection. In a small magazine called the CoEvolution Quarterly, in mid-1975, back-to-back issues presented radically different visions of what it meant to be alive and floating in space. The first looked inward, to warm pools of bacteria and the slow creep of evolution across Earth’s history. The second looked outward, to dark space and gleaming chrome, and a future far from home. The first was called the Gaia hypothesis. The second was physicist Gerard K. O’Neill’s proposal for space colonies. The Gaia hypothesis said humans are part of a vast planetary system, no more able to escape than an organ can live without its body. O’Neill promised the great Earth escape was “Practical, Desirable, Profitable, [and] Ready in 15 Years.”¹

I’ve set up an opposition, but already I’m going to flatten the paper back out, drawing a zig-zagging line between the things that stood on either side of the crease. Because while these visions are opposed, they’re also strangely aligned. They’re both entangled in questions of survival, environmentalism, and political power. And the line connecting them leads right up (with a few detours) to today, and a man who’s been very much in the news: billionaire Elon Musk. While we (or at least I) have been distracted by the decimation wrought by Musk’s DOGE,² or the “white genocide” fear-mongering of his AI,³ Musk hasn’t forgotten his pet project to Occupy Mars.⁴ Now that he and Trump are on the outs,⁵ it seems he may be putting more of his time back into the project.⁶ I don’t particularly care about—or for—Musk’s plans to move to Mars on their own merits. Nor am I certain that such a move is a necessary “life insurance” policy for humanity and even all life, allowing eternal growth long after the Sun is dead.⁷ But I can’t help keeping an eye on these antics. Because as much as Musk may like to set himself apart from fellow billionaire space bro Jeff Bezos, whose space colony proposals draw directly from O’Neill,⁸ Musk is part of the same legacy. And the legacy is not just O’Neill—it’s Gaian, too.

For many of us today, the world feels as if it is falling apart: climate change, war, political corruption, distrust in institutions and in the promise of the future. It was much the same in the 1970s. Think of this essay like a game of exquisite corpse, or a cootie catcher, folding and unfolding the paper to show new connections and combinations. We’re not so much telling the future—although every figure here claims to have the answer to survival—as telling the past, using comparison to find the gaps. We can’t answer definitively whether we are trapped on Earth or can escape, or even whether escape would be for humans alone or for the entire biosphere. But the chimera can remind us where the seams are between altruistic environmentalism and rapacious visions of growth, between sharing the power to change the world and evading responsibility. If we want to reproduce communities of life, what will that take? Whose life is being “insured” through these different imaginaries—and which vision do you choose?

CoEvolution Quarterly was the second magazine in the Whole Earth publication family. Following the shuttering of the Whole Earth Catalog in 1972, CoEvolution Quarterly was inaugurated in 1974 by largely the same team of editors, although this time with a more explicitly biological and environmental bent. Coevolution is a slippery word, especially when it comes to the debates around the Gaia hypothesis. But at its simplest, it stands for how two species can reciprocally influence one another’s evolution. The Gaia hypothesis, introduced to a public readership for the first time in CQ’s sixth issue, was therefore an obvious choice for a cover story.

The Gaia hypothesis was first described in 1972 by an English chemist and medical researcher named James Lovelock. It proposed that the Earth was a single, complex system of interlocking feedback loops, its habitable conditions kept stable by something like planetary metabolism. In early descriptions, as part of this metabolic framing, Lovelock clearly referred to Gaia as alive, a kind of planetary organism. This organismic framing became controversial, especially among biologists, in the 1980s. How could something the size of a planet be considered a form of life if it didn’t reproduce? Biologists and geologists particularly objected to the suggestion that living things were somehow in charge of the planetary system. Lovelock and his key collaborator, the American microbiologist and evolutionary theorist Lynn Margulis, proposed that Earth’s habitability was maintained “by and for the biosphere.”⁹ Intentional curation of an “optimal” environment by and for a collective of organisms struck Gaia’s critics as impossible, even absurd.

Lovelock is often considered an essential figure in the environmental movement, both for his work on the Gaia hypothesis and for a super-sensitive gas chromatograph he invented in the 1950s, which contributed to Rachel Carson’s research on environmental pollutants.¹⁰ The 1970s were the decade of environmentalism. Much of the landmark environmental protection legislation we know today was passed in those years.¹¹ It was a period of widespread concern about resource depletion and the unsustainable growth of human population. It also introduced seminal concepts and publications that would shape the environmental conversation for decades, including “Spaceship Earth,”¹² “One World” discourse,¹³ and the infamous 1972 “Limits to Growth” report prepared for the Club of Rome (a kind of nonpartisan think tank founded in 1968 that was particularly concerned with economics and development).¹⁴ Much of this worry was seeded in the previous decade. Particularly in the United States, concerns that ecologies were being ravaged by human action shuttled back and forth between a focus on damaged landscapes or organisms, as in Rachel Carson’s 1962 Silent Spring, and worries about the consequences for humans, as in Paul and Anne Ehrlich’s 1968 The Population Bomb. Carson emphasized how pesticides, developed to make agriculture more productive, spread through an ecosystem, killing many untargeted organisms and threatening total ecosystem collapse. The Ehrlichs warned of the impending catastrophe of humanity’s (apparently) exponential population growth; soon there would be widespread famine and decimated ecosystems as we ate our way to a lifeless Earth. Fears of nuclear annihilation lingered after the Second World War, fears that often intersected with environmentalism via speculation about nuclear winter.¹⁵ And, of course, the 1960s were the era of the Space Race. So perhaps it’s no surprise that out of the confluence of increasing awareness of the environment and of the planetary scale—and the potential to leave the planet entirely—came the metaphor of “Spaceship Earth.” Spaceship Earth framed the planet as a ship transporting life through the abyss, its ecology and habitable conditions forming a life support system analogous to the technological life support systems of the burgeoning space program.

Lovelock was averse to the framing of Spaceship Earth. But the Gaia hypothesis was clearly part of the same conversation. Lovelock credited it, in fact, to his consulting work for NASA in the mid-’60s. On the strength of his invention of the electron capture detector (ECD), a gas chromatograph far more sensitive than previously thought possible, he was asked to develop chemical life detection instruments for an unmanned mission to Mars. It was in contemplating the unique and chemically confounding composition of Earth’s atmosphere that Lovelock had his Gaian epiphany: the conditions of a planet and the presence of life were actually coevolved features.

Lovelock and Margulis published a handful of scientific papers on their developing Gaia hypothesis in 1974.¹⁶ In Summer 1975, they published an article in CoEvolution Quarterly for the first time. Gaia would go on to appear in the magazine three more times through the 1970s and early 80s, and then once in CQ’s successor, the Whole Earth Review, in 1987. In this first public foray, Margulis and Lovelock stuck close to their scientific data. But they also tried to make the idea as accessible to the curious lay audience of CQ as possible. Central to this aim was the inclusion of a wide variety of diagrams, charts, graphs, and metaphorical descriptions.

A primary metaphor for Gaian thinking is circulation. On the opening verso page of Margulis and Lovelock’s 1975 article is an image from 1664. This is the frontispiece to Sachs von Lewenheimb’s Oceanus Macro-Microcosmicus,¹⁷ which among other things defended physician William Harvey’s theory of how blood circulated through the human body. Von Lewenheimb, as his title suggests, also drew an analogy between the circulation of blood and the Earth’s circulation of water. His frontispiece shows two medallions, one atop the other. The first is of anthropomorphized winds with puffed cheeks blowing on the waters surrounding a mountain. The second is the sketch of a human body, showing only the blood vessels and a strangely blank belly, two manicules pointing at important areas of the body. “Apparently the idea that water lost to the heavens is eventually returned to Earth was so acceptable,” Margulis and Lovelock wrote, “that Harvey’s theory was strengthened by the analogy.” Clearly, they hoped drawing an analogy with this history would do the same for them.

The Gaia hypothesis as Margulis and Lovelock present it here is a clearly organic and planet-bound vision. Life helps explain why Earth looks the way it does, and the planet, especially its atmosphere, comes to be seen as an extension of living metabolism, a kind of extended body of life as a whole (what they call “the biosphere”). Margulis and Lovelock contrasted the atmospheric composition of the Earth with that of other planets. Earth’s atmosphere included stable concentrations of mutually reactive gases, like oxygen and methane, which were strongly associated with living metabolism. Earth without life would be expected to have an atmosphere much more similar to that of its neighbors Mars and Venus, so this compositional disjunction showed the biosphere’s influence on the atmosphere. This coherence between life and planet, however, was not universally accepted, or even considered at all. In the issue of CQ immediately following Summer 1975, a quite different idea had its own debut: physicist Gerard O’Neill’s space colony proposal.

Gerard K. O’Neill was a high-energy physicist and, like Lovelock, an inventor. In 1956, O’Neill proposed a kind of particle accelerator, the colliding-beam storage ring, that is still used in high-energy particle physics today.¹⁸ The 1950s were a period of greatly expanding research in particle physics specifically and in scientific research generally, with scientists keen on proving their essential role for national and global progress in times of peace, not just war. After his work on particle accelerators in the 1950s and ’60s, O’Neill’s attention was drawn to the idea of space colonies in part through exercises with his students at Princeton, where he was a physics professor. He began giving talks at universities and societies on the subject, one of which, at a World Future Society conference in Washington, D.C., caught Stewart Brand’s ear.

CQ’s Fall 1975 cover story on what O’Neill called “the high frontier” (i.e., space) was an adapted version of the World Future Society talk. It was accompanied by an excerpt of O’Neill’s U.S. Congressional testimony on the subject earlier that year, an interview between O’Neill and Brand, and a further enthusiastic promotion of the colony proposal by one of O’Neill’s coworkers, the engineer Eric Drexler. O’Neill, too, was thinking about an interconnected planet, and the influence of living organisms on the environment. But while Lovelock warned that “we are sure that man needs Gaia,” O’Neill suggested that humanity’s exit from the planet might be the best way to preserve both of them. “Now we have that capability,” he wrote of space travel, “and if we have the willpower to use it we can not only benefit all humankind, but also spare our threatened planet and permit its recovery from the ravages of the industrial revolution.”

Reflecting the ovoid aesthetic and iterative model of particle accelerators, O’Neill’s proposed space colonies were smooth cylinders, rotating to provide Earth-like gravity. Artistic renderings showed soaring cities and lush river valleys; O’Neill suggested colonists could “choose and control their climate and seasons,” modeling their landscapes on “some of the most desirable areas of the Earth” and keeping pesky necessities like agriculture to “external cylinders” calibrated precisely to the need of each (assumedly monocultural) crop. O’Neill’s vision was one of an easily achievable technological utopia. “Everything I describe,” O’Neill promised, “is well within the limits of present-day, conventional materials, and of present technology. If we were to start now, with determination and drive, in my opinion the first space colony could be in place, with its productive capacity benefitting the Earth, before 1990.” All it would take would be “an investment not much larger than that of Project Apollo.” O’Neill argued he could keep the cost down by pulling much of the material from the Moon and doing much of the manufacturing in space—a plan that his later imitators in Bezos and Musk have largely copied.¹⁹

Central to O’Neill’s techno-utopianism was his proposal that these space colonies would not only relieve pressure on Earth’s strained resources, they would also allow for endless growth. “Under the space-colony conditions of virtually unlimited energy and materials [sic] resources,” he wrote, “a continually rising real income for all colonists is possible—a continuation rather than the arrest of the industrial revolution.” A capitalist’s dream.

If Gaian thinking saw Earth as a kind of organism, with different species acting as interdependent organs and the planet itself as a body with a circulatory system of water and chemical cycles, it hardly made sense to think of life off the planet. The existence of Gaia meant that humans’—or any species’—desire for endless growth and resources would always slam up against the needs of others and the limitations of a system based on loops that needed to close back around, recycling the components. The so-called human “population bomb” that the Ehrlichs feared in 1968 might destabilize the entire Gaian system and put all life at risk. But it might also, under a Gaian paradigm, only threaten humans, who would grow too big for their niche and then starve back down to their allotted size. (Indeed, the risk that humans would kill themselves off rather than harm Gaia was one Lovelock emphasized in several of his books.²⁰)

O’Neill, by contrast, was accustomed to breaking atoms into separable particles; he saw Earthly organisms and environments as discrete and mobile entities, easily transported elsewhere and reconfigured according to human needs and desires. Not limited by the self-correcting cycles of a Gaian vision, or by the physical limitations of the planetary body, O’Neill’s future humans could experience truly endless growth in space. They would feed on the unlimited supply of solar energy, making ever more spaceships and space stations by mining nearby planets and asteroids for material.

As previously mentioned, the 1970s were a period of intense concern about human overpopulation and subsequent famine (see, for example, Garrett Hardin’s article just before Margulis and Lovelock’s in the Summer 1975 issue of CQ). The infamous “Limits to Growth” report of 1972 was intended to address the large-scale problems facing humanity. A chief caution of the report was that finite Earthly resources placed firm limits on human populations, technologies, and institutions. But O’Neill saw space as an escape from all of this. Why be kept small on Earth, and forced to die with the planet, when humanity could leave all that complexity behind, and live forever among the stars? The creators of the Gaia hypothesis had a kind of rejoinder to O’Neill’s vision of how to reach escape velocity from the limits to growth. It is not necessarily the one you might expect.

In the Summer 1987 issue of the Whole Earth Review, the magazine that merged and replaced CoEvolution Quarterly and the Whole Earth Software Review in 1985, Lynn Margulis published another essay on Gaia. This time her coauthor was her son and frequent writing collaborator Dorion Sagan. Their article, “Gaia and the Evolution of Machines,” reckoned with the exponential growth of technology from a Gaian perspective. It also repositioned the Gaia hypothesis in relation to space colonization and the limits to growth.

“Not only are members of the more than 10 million existing species components of the Gaian regulatory system,” Sagan and Margulis wrote, “but so are our machines. Here we argue that although not by themselves alive, like viruses and beehives, machines are capable of reproduction, mutation and evolution.” Machines evolved and reproduced themselves through the humans who made them, analogous to viruses’ reproduction inside a cellular host, using the cell’s “machinery” (as the typical metaphor has it). Since humans had become so reliant on their technologies (Sagan and Margulis called us “obligate technobes”), and since technology had become so integrated into the environment and affected global feedbacks and the evolution of other organisms, machinic evolution and reproduction were now essential to Gaian processes.

“The debate over what is and what isn’t capable of evolution takes on new fascination,” Sagan and Margulis wrote, “as a close study of waste transformations and an atmosphere steeped in biogenic (including anthropogenic) chemicals reveals that no clear line can be drawn between organisms and their environment.” With no clear line between organisms and environments, and by extension no clear line between life and nonlife, the expansion of machine life represented an important turning point for Gaia as a semi-organic entity. Sagan and Margulis noted that machines would soon start to reproduce themselves, although they did not really speculate on precisely how this would be achieved. Instead, they focused on how machines could lead to Gaian reproduction. One of the primary critiques of Gaia by biologists, largely sparked by an influential review in the Spring 1981 issue of the CoEvolution Quarterly by microbiologist W. Ford Doolittle,²¹ was that Gaia could not evolve or be considered an organism (or perhaps even like one) since it did not reproduce. But perhaps machines, themselves the product of organic (human) evolution within Gaia, could now solve that problem by bringing life to other planets. In fact, technology was already starting to decouple Gaia from Earth, even if Gaia had not yet truly reproduced by creating a fully functioning biosphere on another planet. Sagan and Margulis argued that the Viking landers on Mars, while still operational and in radio communication with the Earth, were part of Gaia’s self-regulating system. Gaia’s reach had therefore already extended past its Earthly body, at least temporarily.

“Gaia and the Evolution of Machines” is a strange article in many ways. On one hand, it emphasizes the expected lines about Gaian interconnection. Sagan and Margulis wrote,

While a Gaian view opposes the atomized science-fiction vision of space colonies free of climatic variation or agricultural pests, suggesting instead that sufficiently biodiverse webs are necessary for survival, it is not necessarily opposed to movement off the planet. The difference is that it wouldn’t be humans taking a few of their favorite toys and trying to make it with mechanical life support systems. (Biosphere II tried a version of this in the early 1990s, building a pseudo-space station in Oracle, Arizona. Even with greater attention to ecological webs and the inclusion of many species, they found it impossible to sustain a separate biosphere without outside intervention.²²) It would have to be Gaian reproduction—a whole biosphere integrated into another planet with its own feedback loops—or nothing. “If we survive our nuclear threat and become a multiplanet civilization reproducing in outer space,” Sagan and Margulis wrote, “this too will not necessarily be a victory for humanity. It will be a victory for the biosphere, for the nexus of all life, inclusive of machines.”

At the start of this essay I promised you a mirror, and a connecting line. But perhaps now things feel murky, and tangled. Is O’Neill’s capitalist vision of space colonies and endless growth opposed to Margulis, Lovelock, and Sagan’s Gaia? Is the Gaia hypothesis environmentalist, in the way it insists on symbiotic planet-bound life, or accelerationist, in its belief that the population bomb of machines could lead to Gaian reproduction in space? And what about today’s proposals for space cylinders and Martian colonies in the hands of Jeff Bezos and Elon Musk? Since Musk advocates for Mars over autonomous stations, is his plan to live in space more likely to succeed?

To misquote media theorist Marshall McLuhan, the muddle is the message. The history of the Gaia hypothesis in the Whole Earth magazines reveals the paradoxes of environmentalism and its politics, particularly regarding both organic and economic growth. Prevailing narratives cast the Gaia hypothesis as an Earth-first vision of harmonious balance, CoEvolution Quarterly as a magazine for left-leaning back-to-the-land idealists, and O’Neill’s space colonies as an irresponsible project to escape all Earthly bounds for a future of endless capitalist growth. Each of these is partly right. But tracing the Gaia hypothesis’s publication history in CQ, and its physical proximity to contrasting ideas in the magazine, reminds us that Stewart Brand and the other editors of CQ were as compelled by libertarian individualism as symbiotic Gaian thought, as keen on protecting American Indian rights as imagining an undying future among the stars, as Malthusian in their worries of catastrophic overpopulation as they were trusting of technology to build utopia. O’Neill’s colonies and Lovelock’s Gaia are mirrors because they are both opposite and the same, with O’Neill’s atomized view of limitless growth prompted by the same concerns of a delicate environment that propelled Lovelock’s emphasis on a symbiotic web of curbs and feedbacks.

The interweaving of these ideas extends to today. The Gaia hypothesis has been recently critiqued on the grounds that it poses a moral hazard—its proposal that the Gaian system can re-equilibrate around new conditions even if certain species die off has been seen as allowing for continued fossil fuel pollution.²³ (This is an interesting reversal from some of the earliest critiques, which saw Gaia as standing for an unreasonably beneficent harmony.) And as for O’Neill’s proposals, it is the avowed environmentalist Jeff Bezos who, still driven by Limits to Growth-style concerns, suggests autonomous space stations to take the pressure off the Earth, while Elon Musk thinks life belongs on a planet. But Musk is also looking for total escape, from finite Earthly resources and from economic regulations and the needs of regular people.

Holding 1975 up to 2025 shows that we’re still learning and unlearning the same things, still trying to make sense of responsibility and interdependence, still fighting about the possibilities of economic growth or degrowth, still trying to find ways to escape into technological utopia. O’Neill, Bezos, and especially Musk have framed leaving the Earth as a pressing question of survival. But if space colonies, on Mars or at L5, are meant to be a life insurance policy, they might not be a good one. If the Gaia hypothesis is right (and it’s possible it’s not!), any protection of one species requires the protection of the whole system of Gaia. (The unfairness of Gaia is that the opposite is not true—the system can adapt, and has adapted many times over, to the death of species without too much trouble.²⁴) We’re probably all in this together. Maybe we can leave the planet. But if we do, we’re going to be bringing existing relationships and responsibilities with us—or at the very least we’ll have to make some strong new ones, fast.

Sagan and Margulis’s “Gaia and the Evolution of Machines” appeared as part of a special issue by something called the “Reality Club,” a hand-picked group of innovative thinkers across many fields whom the founder, John Brockman, thought had potentially world-altering ideas. (For more on this club and its own ambivalent politics, see Sebastian Fernandez-Mulligan, this volume.) On the cover of the issue, the editors of the Whole Earth Review wrote: “What is Real? Reality is an agreement, and the Reality Club is framing the next version.” “Gaia and the Evolution of Machines” frames a new vision of reality, one where a rapid expansion of technology might not lead to the devastation of The Matrix but to the birth of new, living planets. But it’s not clear if this vision has garnered enough agreement to stick. I’m not sure if I agree such planetary reproduction is possible, even on the basis of Gaian ideas. But I know I’d rather live in a reality that recognizes not just entanglement, but ambivalence. Recognizing the double-sidedness of environmental thought, free market colonial dreams, and Gaia itself seems more real, and more responsible, than settling into the easy assumptions that the standard potted histories tell us everything we need to know about reality.

Reality is an agreement. But there’s “reality” and then there are real effects, and the agreement is more than human. It always has been, as the history of Earthly conditions shows. Who’s to say humans will be the only ones “framing the next version”? The more that climate change forces humanity to attend to the agency of the planet, the more those like Musk, self-important and blind to their historical inheritances, insist on the possibility of escape. Maybe they’re right. Gaian thinking, while a caution to such dreams of escape, is strangely open to the possibility under very particular conditions. Should we go to Mars? Probably not. Will it insure humanity’s ultimate survival? Who knows. That doesn’t mean these are not “real” possibilities. But agreements are tricky things, almost never to the universal liking of all the affected parties, and they can be broken. When realities do break (and doesn’t it feel like our reality is breaking these days?) they give those who are paying attention an opportunity to see the seams between things. We catch a glimpse of the way things could have been and perhaps could be, on the next fold in and out of the fortune teller.