ONE SPECIES, OR A MILLION?
Ben Finney
[In the following article, Dr. Ben Finney explores the possibilities of the human exploration and colonization of space, beginning with the moon and Mars. It is a highly speculative piece that raises such questions as "Would it ever be possible?" "Would it be desirable?" "What parallels are there between such an effort and the Polynesian exploration and colonization of the Pacific?" "Would it be more desirable for global human society to make an effort to develop a sustainable culture within the limits of the resources of earth, rather than continue to expand?" This provocative article is the starting point for debate about the future of humanity.]
The launch by the Soviet Union on October 4,1987 of the first satellite to orbit the earth, and then the subsequent spaceflights of Yuri Gagarin, Alan Shepard, Gherman Titov, and John Glenn, inaugurated a new era for humanity. Hitherto bound to our natal planet, people began to venture into space. Since then, American astronauts have set foot upon the moon, and their Soviet counterparts have orbited the earth for as long as a year at a time. Now, space agencies from a number of nations are developing plans to build permanent bases on the moon and to explore Mars. Beyond these initiatives extend even bolder dreams of settling the entire solar system and then of venturing to other star systems.
We are becoming a spacefaring species. Yet we have little idea of what lies in store for us if we continue to expand into space which is not surprizing, given our knack for developing new technologies without thinking about the consequences. We do not even fully realize how the three and a half decades of space activities that have followed the first sputnik have affected humanity, much less what new types of social, political and economic structures will evolve if our descendants do spread throughout the solar system, and what will happen to the human lineage if one day people leave the orbit of our sun to find homes on planets or other bodies circling other stars.
Although such prophets of the space movement as Konstantin Tsiolkovski, Robert Goddard and Hermann Oberrh promised great benefits for humanity would follow from expanding into space, social thinkers have been slow to turn their attention to how venturing into space can impact humanity. The anti-technology bias common among Western social scientists and humanists has blinded most of them from even considering the issue. Sociologist Amitai Etzioni, for example, voiced the opinions of many of his colleagues by dismissing the Apollo program to land men upon the moon as a "moon-doggle" of no use to humanity that wasted billions of the taxpayers' dollars that could have .been better spent on social programs.' Other social thinkers have recoiled at the idea that playing with this new technology will eventually lead our species to leave earth.
Consider, for example, philosopher Hannah Arendt's encounter with the beginnings of the space age. In 1956 she delivered a series of lectures at the University of Chicago in which she considered what she called the "human condition" from what she called "our newest experiences and our most recent fears." From her philosophical perspective, she said that three great events had shaped the modem age and determined its character: the discovery of America and the ensuing exploration of the entire world; the Reformation and subsequent social and economic transformations; and the invention of the telescope and the revolutionary perspective on the earth and the heavens that followed. Before, however, these lectures could be published another great event occurred: the launching of the first sputnik.2
Two years later when Arendt published her lectures in a book entitled The Human Condition, on the very first page she hailed the launching of that first artificial satellite of earth as an "event, second to no other." She was disturbed, however, over enthusiastic proclamations that this constituted the first "step toward escape from man s imprisonment on the earth," for to Arendt "the earth is the very quintessence of the human condition." "The most radical change in the human condition we can imagine," Arendt declared, "would be an emigration of men from earth to some other planet." Yet, in her book she did not develop this theme. Not only was the idea of venturing into space was too new and shocking for Arendt to contemplate, but her philosophical outlook hardly prepared her for thinking about what might happen if we truly succeed in expanding permanently into space.3
Not surprisingly, given their materialistic outlook, Soviet social thinkers have been quicker to consider what this developing capacity to move into space means for the human condition. In the late 1970s, philosopher Arkady Ursul, sociologist Yuri Shkolenko and cosmonaut Vitali Sevastyanov summarized Soviet thinking on the subject in a far-reaching book entitled The Universe and Civilization. Quoting liberally from Marx and Engels, as well as modem space scientists and commentators from the East and the West, these authors examine the impact of space developments on the human condition. From a social and philosophical point of view, they label the changes in society and human consciousness that have followed from our entry into the space age as manifestations of a process they call "cosmicisation." Concrete examples of cosmicisation that they discuss include the development of new vistas in science opened by the use of space probes and satellites for research,the benefits flowing from the employment of satellites for communication, remote sensing and navigation, the promotion of an ecological awareness of the fragility of our biosphere inspir~d byrhose first photographs from space of our lonely blue planet, and the new production and social relations that will emerge as we begin to exploit the resources of space.4
These Soviet authors also discuss the colonization of space. They argue that the settlement of the solar system, and then interstellar migration, is inevitable, and castigate such Western writers as C.S. Lewis and Loren Eiseley for their insistence that humans should stay on earth. Yet, they do not explore the implications of the spread of humanity into space, and in fact insist that the earth and its people must remain the central point of reference for all space activities. While they stress that it was the Russian space pioneer Konstatin Tsiolkovski who proclaimed that it is man's destiny to spread into space, these Soviet analysts declare that this original conception has "been supplemented by a kind of 'feedback' aimed not at escape from earth but at a closer man-made bond between earth and outer space." Indeed, their largely geocentric approach is inherent in their definition of cosmicisation as "the effect of space factors, forces and processes on various domains of the conscious and goal-direction activity of men on earth."5
It is tempting to speculate that this partial retreat from Tsiolkovski's bold initial vision of humankind's destiny in space may reflect thinking during the Breshnevian period of stagnation in which they were writing. It should also be noted, however, that a parallel shift in emphasis occurred during the l970s among many Western space enthusiasts who, once they saw that unlimited funding would not be available in the post-Apollo period to fulfill their dreams of immediate voyages to Mars and beyond, changed their tactics to emphasize the more immediate benefits to mankind that flow from space activities. Nevertheless, whatever the reason for this shift, it seems that the focus of these Soviet writers on the earth-space bond has prevented them from exploring the full implications of developing the ability to leave our natal planet.
There is a need for a more open perspective that transcends the earth-space relationship, and considers the possibilities inherent in the spread of humanity throughout space. The discipline of anthropology, particularly in its American formulation which embraces both biological and cultural evolution, provides such a perspective.6 As an anthropologist conscious of our evolutionary past and concerned about our long-term future, in this final essay I will attempt to illuminate the coming impact on humanity of venturing into space. As a philosopher, Hannah Arendt referred back to the thinkers of ancient Greece and their world view to develop her analysis of the changing human condition. As an anthropologist, I reach back some five million years to the dawn of the human lineage, survey the biological and cultural steps in human evolution that have brought us to the threshold of space, and then attempt to project the trend of human evolution far into a future in which our descendants will have learned to live and prosper in space.
The Human Lineage
Let me begin by stating a thesis. We evolved as an exploratory, migratory animal. The human lineage began in East Africa, slowly expanded over the African continent, and then into Asia and Europe, and finally to the Americas, Australia and the islands of the sea. Our ancestors were able to spread from their tropical homeland through developing technology to travel to and survive in a multitude of environments for which they were not biologically adapted. Migrating into space, and the development of transport, life support and other systems which will be required for the spread and maintenance of human life there, represents a continuation of our terrestrial behavior, not a radical departure from it. Yet, while colonizing space may be a very human activity, such a move would in turn radically transform humanity. By following our exploratory bent, and by exploiting our knack for technological innovation, we will enter into an era of accelerated evolution, first cultural and then biological. Faced with new challenges, forced to adapt to myriads of new environments, and dispersed in discrete communities scattered far and wide throughout space, humanity must change, again and again. If we migrate into space the human condition will be utterly and inalterably transformed.
To develop this thesis, we need to first consider key elements of the evolution of our species and its spread over the globe, and then attempt to look into the future and think about the consequences of migration into space.
The first giant leap for mankind, to borrow a phrase from Neil Armstrong, was the descent from the sheltering trees of the tropical forest to the grasslands of the savanna made by our distant ancestors, who in so doing virtually set human evolution in motion. These were literally the first steps toward humanity, for they were made on two legs instead of four. This revolution in posture left the forelimbs free to carry objects and above all to make and employ tools, for it is this growing technological capacity that has made our evolution so unique.
We humans are hominids, the sole surviving species of a lineage of erect-walking primates. The available evidence indicates that the human lineage began evolving in Africa, specifically East Africa. As Darwin pointed out over a century ago, our closest relatives, the Chimpanzee and the Gorilla, come from Africa, and it is in East Africa that the earliest bipedal fossils have been found. These date back some three to four million years ago, but are not thought to represent the oldest of our hominid ancestors. New techniques in molecular biology have yielded insights into the divergence of the human lineage from that of the other apes, indicating that the first hominids may have appeared some five million years ago.
If the first known fossil hominids, those of the genus Australopithecus, are any indication, our first bipedal ancestors were not mighty hunters who slaughtered big game with spear and club. Although her male counterparts may have been more robust, the famous Lucy, the earliest preserved Australopithecus skeleton, stood barely over a meter in height, probably weighed under 30 kilos, and lacked powefful canine teeth and other specializations of predators. These early hominids probably depended primarily upon roots, berries, nuts and other wild vegetable foods, supplemented by eggs, insects and small animals they caught or scavenged. Although archaeological evidence is so far lacking, it is generally thought that they used rudimentary tools
digging sticks, stone pounders, simple containers of bark and skin -to help them gather, process, and carry their food.8
Yet, despite this technological beginning, and the postural revolution that made it possible, Australopithecus apparently did not expand beyond the savannas of Africa. Evidence for migration out of Africa only comes with the evolution of a new genus and further technological advance.
While Australopithecus may have stood erect, its brain remained small, averaging around 500 cc, hardly bigger than that of contemporary chimpanzees. Then, starting about two million years ago, the evolution of the brain began to accelerate. The first evidence comes from a skull of around 650 cc found by the late Louis Leakey at Olduvai Gorge in Kenya. Both because of its larger brain, and the fact that stone tools were found in association with fossil remains, Leakey classified this creature as the first known representative of our genus, Homo, and gave it the species name of habilis to denote its handiness with tools. Although recent discoveries indicate that Australopithecus also used rudimentary stone tools, by the time of Homo habilis the distinctly human synergy between the development of increasingly sophisticated tools and the acceleration of brain development was apparently well underway.~
Yet, these early representatives of our genus were not the first to migrate from Africa. The first human fossils found outside Africa belong to a new species, Honio erectus. This species had a larger brain; its range of from 775 cc to 1225 cc overlaps the low end of the range for contemporary Homo sapiens. This species also employed a more highly developed stone technology, apparently inventing the art of chipping stone tools on both sides to make a sharper edge. With better tools, weapons, and, presumably, cooperative hunting methods as well, erectus populations began to prey on larger and larger animals. They also were able to migrate out of Africa and fan out across Eurasia, where fossil remains have been found spread from Western Europe to China and as far south as Indonesia.
In Europe and Asia this tropically-adapted animal must have found it difficult to survive the cold, particularly during times of glacial advance. Yet, archaeological evidence indicates that bands of Homo erectus roamed far north to exploit the game-rich grasslands there. Cultural rather than biological adaptation was the primary means for survival. Archaeological sites indicate that they built rudimentary shelters, and wore animal skins and kept campfires to protect against themselves against the elements.
Despite the evidently considerable hunting skills and technological ingenuity, Horno erectus does not appear to have spread beyond the linked continents of Africa, Asia and Europe. The move to the Americas and Australia required further cultural development and the appearance of a new species, Homo sapiens.
Exactly where and when our species originated has not yet been definitely established. Some recent research on mitochondrial DNA suggests that Homo sapiens may have arisen in Africa some 200,000 years ago, and then spread over that continent and then Eurasia, where they replaced existing erectus populations. Many paleo-anthropologists relying on fossil evidence argue, however, for a more diffuse origin of Homo sapiens out of erectus populations spread over Africa and Eurasia. Whatever the exact origins of Homo sapiens, and the position of the Neanderthal populations in this evolution, the main point of this narrative is that Homo sapiens were the first to populate the hitherto empty continents. 0
The lowering of sea levels by a 100 meters or more during the last glaciation between 80,000 and 12,000 years ago provided the opportunity for these migrations - by exposing the continental shelves so that Siberia and Alaska were joined, and most of Indonesia became an extension of Asia reaching out almost to the shores of a great continent formed by a joining together of a glacially-enlarged Australia and New Guinea. With this change in sea level, bands of hunters from the far northeastern end of Asia had only to walk across the grassy plains of Beringia to reach what is now Alaska. To reach Sahul, as the continent formed by the linkage of Australia and New Guinea is called, people had only to rafr across the narrow ocean gaps that separated the Indonesian extension of Asia from this great offshore land mass."
Yet, previous glaciations had similarly lowered sea levels without any migrations taking place. The crucial ingredient to inter-continental expansion must have been the development of human cultural capacities and techniques. Refined hunting tools, tailored skin clothing and other survival gear enabled hunters to penetrate far into the Siberian Arctic, and then to follow their prey to the New World. Similarly, rafts and techniques for living off the sea and coastal resources had to be developed before people could cross from Asia to Australia and New Guinea.
In surmounting tropical and arctic barriers, and then in spreading over the forests, mountains, plains, deserts and jungles of the world, these wanderers utilized the uniquely human ability to adapt culturally to new environments. Building on the biological foundation of erect posture and brain expansion, our recent ancestors developed further the human capacity to invent and apply technology, thereby making human existence possible from Africa to the Americas, and from the tropics to the arctic. Where other animals had to adapt biologically to move into environments radically different from the ones in which they evolved, Homo sapiens, the hairless biped from the African savanna, could adapt culturally.
To claim, however, that late Pleistocene Homo sapiens spread over the entire world is to ignore that we actually live on a water planet. Seventy percent of the earth's surface is water, and it is only in comparatively recent times that people have learned how to sail far out to sea. The first people to do so were canoe voyagers whose expansion begins along the shores of South China and Southeast Asia some 5,000 years ago, and culminates with the discovery and settlement of just about every inhabitable island in that vast oceanic realm we call Polynesia.'~
Yet, however superbly adapted the Polynesians were for colonizing oceanic islands, once they had settled all the available islands in the Pacific their expansion stopped. The next major milestone in the evolution of human maritime abilities came with the accomplishments of the European navigators who, in learning to sail between the continents, and eventually around the world, were the first to demonstrate that there is but one ocean, and that it could be used as a highway to connect hitherto isolated lands and populations. The story of the development of seagoing ships and navigation, of the forging of military, political and commercial instruments for expansion, and of the consequent decimation and subjugation of peoples around the world that followed, is well known. Here, I wish to emphasize the global consequences of this development, and to stress that this maritime age of discovery led directly to the bringing together of the many scattered branches of humanity into one global economic system, in effect completing the first, terrestrial, phase of human expansion, and setting the stage for the second phase of expansion into space.'3
The Exploring Animal
What can be said about the basis for this global expansion of humanity beyond the apparent truism that life expands to fill all niches, and the corollary that through both biological and cultural evolution humans are uniquely adapted for expansion? Is there something more to the spread of humanity than just the capacity to develop technologies and organizations for expansion? I raise these questions in order to focus on the premise that we are by nature an exploratory, migratory species, and to examine the issue of motivation.
Exploration is not, of course, unique to humans. In most species, however, the juveniles do the exploring, investigating their environment before settling down on a limited geographical range from which they, as adults, may seldom stir. Modem humans follow a similar pattern of juvenile exploration before settling down to the routine of adult life. Yet, some adults do not give up their exploratory bent; they may even make a career of it. Columbus did this through sheer force of personality; by the late 18th century maritime exploration had matured to the point where Captain Cook could claim to be "employed as a discoverer." Now, there are those who make their living exploring the stars and planets through telescopes and robot spaceships, and a growing core of cosmonauts and astronauts are exploring space directly. We are an animal that has turned a juvenile characteristic into an adult profession.
This development may be as much a part of our genetic heritage as it is of our cultural evolution. Adult humans resemble juvenile apes in their large brains, globular heads and lack of protruding muzzle, a comparison which has led to the theory that we have become large-brained humans through the process of neotony - through changes in growth rates that have acted to preserve foetal and juvenile characteristics far into maturity. At birth, infant apes and humans are much alike in brain size and facial proportions. However, while the sutures close early in an ape's skull, and its brain grows little as its brow thickens and it develops a protruding muzzle, our sutures remain open and our brain continues to grow through a prolonged infancy and adolescence. We then reach maturity with underdeveloped jaws and teeth tucked under the bulbous forehead of a child, a neotonous process that, says paleontologist Stephenjay Gould, has in a relatively short period nearly trebled the size of our brain.'~
Ethologist Konrad Lorenz extends this theory of human evolution through neorony into the behavioural realm. Our hypertrophied urge to explore may be regarded as a behavioural manifestation of our neoronous development, for we - or at least some of us - retain the juvenile penchant for exploration and investigation of our environment far into adulthood. According to Lorenz, this retention has served us well, for from it comes our inquisitiveness into the nature of things as well as our constant search for what is over the horizon. In other words, it is the source for both science and exploration. Through this neotonous process, perhaps modulated by the mutation of only a few regulatory genes, we have become a most inquisitive, exploring animal. '~
But, this inquiry into the behavioural consequences of neotony does not answer the question of why some human groups have been manifestly more exploratory than others. Why do some people (or some people in only some historical epochs) strike out for new lands, while others have been seemingly content to stay put? So broad a question, with so many particular instances to explain, is really impossible to answer. However, if we narrow it down to the exploration of the sea, there is one episode of human expansion that is most thought provoking.
The exploration of the sea and the discovery and settlement of new lands is the phase of humanity's spread over earth that is most evocative of our future expansion into space. American and European space enthusiasts often recall the European "discovery" of the New World of the Americas as a model for future expansion into space. It is not an appropriate parallel, however, anymore than is the European "discovery" and occupation of the islands of southeastern Polynesia considered in the last essay. Columbus and his successors came to already populated lands, whose people they decimated through disease and overwhelmed militarially, economically, and culturally. To find a more fitting oceanic parallel to the coming expansion into space we need to find an example of overseas expansion to lands never before seen by human beings.
The Polynesian discovery and settlement of the far-flung islands of the mid-Pacific provides just such a case, for the adventure of exploring the unknown to establish colonies on worlds never before occupied or even visited makes this oceanic migration relevant to the one about to unfold in space. Furthermore, the development of new technology was as crucial to expansion into the Pacific as it will be for settling space. Just as we are now striving to develop the means to spread human communities into space, so did the Polynesians disperse far and wide through an alien environment through developing large sailing canoes, precise methods of navigation, and a portable agricultural system to ensure survival on the fertile but biotically-impoverished islands they found.
Rather than belabor these parallels, however, let me raise the even more crucial question of why these stone age seafarers showed such a genius for expansion. Why should they, and their immediate ancestors, have been so precocious as ocean explorers and islands colonizers? To merely say that Polynesian culture was adapted to exploration and colonization explains nothing. The question is why should their culture have developed its expansive outlook.
Let me begin to answer that by posing a series of apparent paradoxes. Europeans did not colonize the mid-Atlantic islands of Madeira and the Azores until the 15th century, 3,000 years after the stone age voyagers whose descendants were to be the first Polynesians reached the mid-Pacific archipelagoes of Fiji, Tonga and Samoa. Rapa Nui (Easter Island), one of the world's most out-of-the-way specks of land, was colonized before comparatively huge and and easy-to-reach Iceland. Hawai'i was settled by voyagers stemming ultimately from far off Southeast Asia, and not from the comparatively nearby continent of North America. These paradoxes would seem to violate common sense reasoning that technologically advanced peoples should be the first to settle oceanic islands (or at least to settle the most distant ones), and that islands should be settled by the continental peoples closest to them.16
These can be resolved, however, if we consider that it is the patterning of oceanic islands that is crucial to island colonization, and not the absolute proximity of islands to continents or the technological level of the people living along adjacent continental shores. The distribution of Pacific islands was ideal for promoting island colonizarion from the shores of Southeast Asia. The extended arc of islands immediately offshore the Southeast Asian mainland promoted the development of a maritime way of life, while the rich collection of continental fragments and volcanic islands that extends eastwards from island Southeast Asia two-thirds of the way across the Pacific beckoned people to sail farther and farther out into this great ocean in search of new island homes, and gave them a proving ground where they could incrementally develop their seafaring and colonizing capabilities.
In contrast, the lack of a stepping stone pattern in the sparse, uneven distribution of islands in the middle latitudes of the Atlantic and in the eastern Pacific as seen from the Americas, provided little in the way of encouragement and experience for people to attempt to seek out distant island homes. Hence, migrants stemming ultimately from Southeast Asia spread far out into the Pacific while people from the Americas and Europe either did not venture far out to sea, or did so after all the Pacific Islands had been found and settled.
Not only did the patterning of islands in the Pacific encourage people from the western shores of that ocean to sail farther and farther to the east, but the increasingly wider gaps between islands as one moves east from the Southeast Asian mainland led the migrants to progressively refine their voyaging technology and colonizing skills in order to sail farther and farther out to sea. While the closely spaced islands of Southeast Asia provided the cradle for oceanic voyagers, it was the open Pacific with its far flung islands that both attracted these migrants and stimulated their colonizing capabilities.
Colonizing the solar system
But what does all this have to do with space migration? To begin to answer that, let me quote the late Krafft Ehricke, a veteran of both the German and American space programs and a proponent of what he called the "extraterrestrial imperative" of our species to migrate into space. At the closing address of the first NASA lunar settlement conference, held in 1984 just a few weeks before he succumbed to leukemia, Ehricke proclaimed that, "If God wanted man to become a spacefaring species, he would have given man a moon," and then went on to detail how learning how to live and work on our nearby satellite would be the first step towards putting humankind firmly in space. He even declared that those who learned to live permanently on the moon would become tomorrow's "Cosmopolynesians" poised on the lunar shore of space, ready and willing to embark on voyages to other worlds.'7
I would add to Ehricke's words by saying that, "If God wanted humans to migrate into space he would have given us not only a moon, but also a rich collection of planets, asteroids, and comets," which, of course, is exactly the case. If the earth was the only body orbiting the Sun, then migration into space might never occur, or would be slow in coming. There would be nothing between us and the nearest stars to entice us from our lonely planet, and allow us to learn how to live extraterrestrially. We would be like inhabitants of a great continent bordered by island-less seas who therefore lacked either the incentive or the incrementally-developed skills to venture far out to sea. But, like those canoe voyagers from Southeast Asia, we are blest with a series of new worlds to draw us from our own. Co-orbiting with us around the sun, we have a marvellous collection of "dirty snowballs," giant gas planets, and carbonaceous fragments, as well as rocky, metal-rich worlds like our own, whose resources beckon would be space colonists.'0
Among space enthusiasts, scenarios abound as to how we could colonize space. One group focuses upon making the planets livable, starting, for example, by turning the moon into an industrial outpost and then moving on to Mars where, through a process called "terraforming," an atmosphere would be built up to moderate the climate and provide breathable air so that humans could live on the Martian surface without the protection of artificial biospheres and thick shielding from cosmic rays. Another group, led by Princeton physicist Gerard O'Neill, envisages using lunar soils, rich in iron, aluminum and silica, to construct huge orbiting habitats within which veritable space cities would be built.'9
However contrasting these approaches may seem, both feature an element universally considered to be essential for successful human expansion into space: the utilization of extraterrestrial resources for everything from building structures to providing water and air. Since it would be prohibitively expensive to ship building supplies, water, air and other needed materials from earth's deep gravity well, it follows that these must be produced in space near (in terms of energy costs) to the place where they are to be used. This, in turn, mandates the beginning of a solar system economy, for the uneven distribution of resources within the solar system dictates that materials would have to be drawn from more than one place. Lunar rocks and soil, for example, may be rich in oxygen, but contain no hydrogen other than minute amounts implanted by the solar wind. Therefore, to produce life-sustaining water hydrogen must imported. Because of the energy required for spaceships to climb out of the earth's deep gravity well, delivering terrestrial hydrogen to the moon would be prohibitively expansive. In contrast, the hydrogen-rich carbonaceous asteroids could be relatively cheap sources for hydrogen. Despite the great distances involved, the comparatively slight gravity of small asteroids means that it would require much less energy to dispatch hydrogen from them to the moon than from earth to the moon.
Of course, it could be argued that these dreams of colonizing Mars, building orbital space cities and tapping the resources of the asteroids and other bodies in our solar system are far beyond human realization. The impact of a large comet or asteroid, or a holocaust occasioned by an all-out nuclear war, could destroy modern civilization before the migration could start. Or, worsening economic conditions might prevent allocation of the huge amount of resources needed to initiate solar system colonization. Or, it may turn out that we are simply not suited to living permanently off the earth. The harshness of airless, intensively radiated space environments, the difficulties of developing artificial ecological systems, the loneliness of life in confined habitats so far from friends and relatives, as well as familiar sounds, slights and smells, and other, unforeseen, difficulties may act to limit the human presence in space to outposts containing only small groups of temporary, or at best semi-permanent, inhabitants.
Even, however, if only a limited human presence in space would be practicable, the inner solar system could still become crucial to life on earth. Solar power stations could be built in orbit, or on the moon, to convert sunlight into electricity and then beam it down to our energystarved planet. Mining bases on the moon, Mars and selected asteroids, along with manufacturing facilities to utilize the mined materials to make rocket fuel, as well as components for space stations and planetary bases assigned to scientific, industrial and military tasks, could also be part of such a space future, for they might be operated with a combination of advanced robotic techniques and the services of crews shuttling back and forth between earth and space on temporary tours of duty.
While such limited space activities would certainly not have the far-reaching consequences that would follow from the growth of human populations in space, they would nonetheless significantly impact the lives of those living on earth. Earth-orbiting satellites have already globalised communication, enabling us to talk easily with people practically anywhere on earth, and to watch momentous events such as the fall of the Berlin Wall or the liberation of Kuwait as they unfold, and further satellite developments would accelerate this process. Beaming, via microwave, electricity from solar power stations in orbit or on the moon could greatly enhance life on earth- without the dangers of radiation from nuclear power plants or of global warming and other unwanted consequences of conventional power plants powered by fossil fuels. Similarly, the shifting of other industrial processes outside of our fragile biosphere could also greatly reduce pollution within our biosphere. Furthermore, scientific understanding of the earth would grow from more sophisticated and intense remote sensing from space, as well as from surveys of the moon, Mars and other bodies in our solar system.
But, without the establishment of permanent colonies in space, and their expansion through resource development and population growth, the impact of the space age would stop short of being truly revolutionary. Suppose, however, that the barriers to space colonization can be overcome. If no natural or man-made disasters befall us; if terrestrial governments or other organizations are able to allocate sufficient resources to start a movement into space; if ways can be found to avoid the damaging effects of cosmic radiation; if large space biospheres capable of supporting great numbers of people can be developed; and if emigrants from earth can learn to conquer feelings of fear, loneliness and nostalgia - then the colonization of the solar system could follow.
This colonization could proceed through the settlement on the moon, Mars, the asteroids and other natural bodies; or through the use of resources from those bodies to build large artificial habitats in interplanetary space; or, more likely, both direct planetary settlement and the development of interplanetary habitats would evolve together to provide a range of opportunities for human expansion throughout the solar system. Whatever the case, if the solar system as a whole becomes the province of humanity, then we must be prepared for radical changes in the human condition.
Consider, for example, the population implications. A case can be made that whereas population on earth must be limited to not many more billions than we already have, within the solar system as whole there is room for many tens of billions of people. Of course, this expansion of the human community would hardly come about through emigration from earth, for the cost of sending millions upon millions of emigrants into space would be truly astronomical. Indeed, there would be no need to send large numbers of colonists into space in order to develop maj or populations in the solar system. As the history of the colonization of virgin oceanic islands indicates, population growth curves rise steeply when people expand into previously uninhabited regions. Of course, some change in the attitudes and institutions would have to take place, lest we send into space the low birth rates of our industrial societies. Assuming that any social or physical obstacles to population growth in space could be overcome, it would not take too many generations for an initial population of a few hundred to expand into the millions, and then the thousands of millions. Although such models of solar system colonization such as David Crisswell's in which hyper-advanced solar engineering techniques provide the energy to support as many as 8 x 1016 people may seem outrageously far-fetched, it is not difficult to imagine that one day many more people could live off earth than on our planet.zo
To envisage this prospect of people living throughout the solar system, and trading, visiting and telecommunicating with one another, we must be prepared to expand our notions of large-scale human systems. Recently, it has become commonplace to talk about the world economic system in which every nation, city, village and tribe is linked together, albeit unequally, in a global network of production, trade and consumption, and about how the creation of this system has broken down barriers that once separated continent from continent, region from region and country from country. World systems theorists stress the economic motivation behind the creation of the world system - how the economic crisis of post-medieval Europe drove rapacious traders and rulers to pioneer transoceanic trade and then seek overseas colonies - and focus on how capitalism evolved as European sea powers organized global economic relations for their benefit.21 But, we must not forget the technology that made the erection of the world system possible: ships capable of spanning the world ocean, and means of navigating them safely from port to port. Now that we are developing the new transport technology for spanning the immense distances of space, and the means by which our descendants will be able to live in a variety of space environments, we should look forward to the establishment of a new, trans-planetary economic system that will one day dwarf our current global one.
Astronomers label the sun and all the comets, asteroids and planets (and their satellites) revolving around it as making up our "solar system," a conception that stresses the common origin of all these bodies as well as the gravitational bonds that tie them together. With the colonization of the moon, Mars, the asteroids and other bodies and locations revolving around our sun, the term solar system will take on a new meaning, and solar system theorists will not just be astronomers, geologists and physicists. Economists, political scientists, sociologists, and perhaps new categories of social scientists more appropriate to this phase of human expansion will turn their attentions to the "solarsystem system."
A truly solar-system economy would dwarf its terrestrial parent, for space colonists would have at their disposal far more solar power that that which bathes the earth and is stored in fossil fuels here, as well as the immense amounts of minerals and elements to be found in abundance on the various planets and asteroids. How that economy might be organized can only be guessed. Would all extraterrestrial components be colonial dependencies of the earth, or would the growth of extraterrestrial wealth and trade between extraterrestrial outposts so exceed earth wealth and trade relations that the mother planet would become a quaint, if slightly backwards, tourist attraction? Given improvements in information technology, one can imagine all economic activity, from the smallest asteroidal settlement to the largest planetary unit, being organized into one highly unified system, operated according to free market principles, or a degree of central direction, or some combination of these. Alternatively, it is much more interesting to speculate how a solar system economy might be highly polycentric, with many different types of organization coexisting within a loosely coordinated network of quasi-autonomous units.
For example, what kind of an organization might result when workers in an orbiting space habitat manufacturing solar power satellites or some other valuable export product, organized a leveraged buyout of their facility from its private or governmental owners?
Would this result in some form of "peoples' capitalism", or some variety of high-tech communism undreamed of by Marx, in which the inhabitants of an artificial world shared equally in the ownership in the habitat, the means of production and the revenues generated? Or, will these concepts be obsolete in the new, solar system economy?
How would a populated solar system be organized politically - as a conglomeration of many independent units, or as a unified polity? Perhaps both possibilities might occur - in sequence. A common theme in science fiction is for space colonies to declare their independence from earth, or whatever entity on earth established and nurtured them. If that were to be the pattern, then we might look forward to a solar system populated by myriads of independent high-tech city-states. However, there is a further possibility, also frequently explored in the science fiction literature. As space colonies would multiply in the inner solar system, it is easy to imagine the growth of huge new political units within which individual colonies become submerged in mass societies comprising many billions of people.
If such a centralization were to occur, there might still be room on the frontier of human settlement for small, separatist communities made up of people who could not stand centralized political control and the tyrannies inherent in mass society. For example, the scenario of space colonization that excites physicist Freeman Dyson is one in which the cost of space travel and the construction of space habitats falls to the point where a small group, such as a voluntary association or a religious sect, could afford to colonize their own asteroid, or even, if technology proceeds apace, one of the billions of comets of the distantly-orbiting Oort Cloud of comets. He sees this possibility as the one hope forhumanity of escaping the stultifying effects on the human spirit of life in large and regimented space colonies. Such a safety valve of small group colonization might promote a needed cultural diversity, bringing forth a multitude of different social experiments from which might emerge brilliant new ways of organizing society.22
Whatever the details of how life will be organized in circum-solar space, it seems safe to forecast that the successful colonization of the solar system would lead to a major shift in how we think about ourselves and the cosmos. By then we would have realized that we are no longer bound to earth, and that it would be within our power to establish virtually anywhere in space unoccupied by other competing organisms. The world view of earth-bound humanity would then be replaced by a truly cosmic view. At this point human consciousness would be almost literally adrift in space, and Arendt's fears that space colonization would lead to a radical change in the human condition will have been realized.
Were we to meet our space-dwelling descendents of future generations we might have difficulty in comprehending their new consciousness. For example, many of those first European voyagers to encounter the Polynesians were not able to understand the uniquely oceanic quality of the history and lives of these islanders. In addition to underestimating the islanders' voyaging technology and seamanship, these Europeans were guilty of projecting upon the Polynesians the values and outlook of continental people. To the Europeans the world was composed of land masses inconveniently interrupted by dangerous stretches of water. What the Polynesians and their ancestors had learned in their long migration was that the world was an ocean strewn here and there with bits of land, and that if they kept sailing in any direction they would eventually find land. They did not regard the ocean as an alien environment, but one which was utterly natural -and essential to the spread of human life.
Here is where the Soviet concept of cosmicisation to denote a change in human consciousness that is developing through the exploration and utilization of space may really become relevant. As our descendants progressively colonize the solar system we can expect that at least some of them will become more and more cosmicised. They will undergo a change in consciousness analogous to that experienced by those seafarers who colonized the Pacific islands, but one of much greater import for the future of humanity. As they learn to live in a variety of space environments, and to travel freely within the solar system, they will regard space, not the earth, as their natural habitat, and look forward to voyaging to other planetary systems where they and their descendants might flourish. This cosmicisation of humanity may be the final, cultural, product of the colonization of our solar system.
Interstellar Migration
Seen in this light, the settlement of nearby planets, asteroids and interplanetary space would form the necessary prelude to interstellar migration. By learning how to build viable habitats in a variety of space environments, by learning how to make life flourish in these created biospheres, and by learning how to adapt culturally to the challenges and rewards of space living, our solar system descendents would have developed more than just the technical means for establishing human colonies outside the solar system. They would have developed the cosmic view required for making so unearthly a step as migrating beyond the pale of our nurturing star.
At this point, if not before, the reconnaissance of other star systems to locate and explore environments suitable for implanting human life would be undertaken in earnest. Similarly, the search for extraterrestrial intelligence by radio observation, and perhaps the sending of robot spaceships to distant star systems to probe them for evidence of intelligent life, would be vastly intensified, for it would then be vital for our species to know if we are alone in the Galaxy, and therefore free to expand.
Let us assume, as contemporary and preliminary observations lead us to believe, that a significant portion of the star systems of our Galaxy are hospitable to human life. Let us further assume - although here both theory and observation lag - that any extraterrestrial civilizations are so widely dispersed that there would be plenty of room in our Galaxy for expansion. Then, the problem would be how to cross the immense distances to reach new new worlds revolving around alien suns. To reach habitable star systems there must be developed either very fast interstellar spaceships which could make voyages to other star systems within a human lifetime, or slower interstellar arks in which generations of space voyagers might be nurtured in order to deliver a final, colonizing generation to a distant destination. Here, there has been no lack of ingenious plans. For example, one of the latest ideas for solving the problem of providing enough fuel for a spaceship employs a variation of the light sail idea. It involves building a solar-fueled power station from materials mined on Mercury, then placing it in close orbit around the sun to capture maximum insolation, and then using it to produce and beam microwaves to push a spaceship equipped with a giant microwave sail towards a nearby star.
As for interstellar arks, the ideas of O'Neill about fabricating very large space habitats from lunar materials have led to a number of recent elaborations of the venerable science-fiction themes in which such habitats are converted into "world ships" and sent on multi-generational voyages to other star systems. Astrophysicist Eric Jones and I have suggested an even slower method of interstellar travel:
colonize some of the billions of comets of the Oort Cloud, and then nudge these cometary colonies out of their solar orbit and send them on a 50,000 or more year voyage to another star.23
While none of these plans are, of course, anywhere near to being realized, given human ingenuity, and the drive to spread into space that would intensify as people become more and more cosmicised, it is not difficult to imagine that sometime in the future the problem of interstellar flight might be solved. Let us again assume that some manmade or natural catastrophe does not extinguish human life, which in this era would be much more difficult to accomplish, as our species would not be concentrated on a single fragile planet. Then, with the technology of interstellar travel and space colonization, with the wealth base of an immense solar-system economy, and with a strongly developed cosmic attitude favoring expansion, there is a good reason to believe that some of our descendants will attempt to emigrate from our solar system, and that at least some of them would be able to establish humanity among the stars.
To imagine the possible outcome of this migration, let us try to peer millions of years into the future, for if we must look back five million years to examine the beginnings of humanity, we should be prepared to look at least that far into the future in order to think seriously about where we are going, For purposes of developing this distant perspective, let us suppose that some adventurous spacefarers have been successful in establishing colonies in nearby star systems, and that these colonies in turn have sent out migrants to other star systems, and so on until our sector of the Galaxy is filled with millions of earth-descended societies. In this extreme, though logical, outcome of humanity's urge to explore and expand, what would happen to the human condition?
Interstellar Evolution
To be sure, it is utterly impossible to forecast so far into the future. However, by focusing on human evolution we can foresee one broad theme. If our descendants spread far and wide among the stars, then humanity must diversify, first culturally, then biologically. Diversification would follow separation, for once settlements become separated by light years, humanity could no longer remain unified.
Consider first cultural diversification. Each new colony would in effect become an independent cultural experiment. New and disparate ways or organizing society, of allocating goods and services, of defining what is just and moral, and so on, would be chosen by conscious design, or would develop through random cultural drifr or other forces. This diversification, which would increase as humanity spreads and the frontier expands farther and farther outward from earth, could not be reversed by the organization of galactic empires -unless travel much faster than the speed of light would someday be possible. For societies separated by scores, if not hundreds, of light years, even the ability to travel at some significant fraction of the speed of light would not enable structures of political domination to be maintained.
Nor, necessarily, could information exchange at the speed of light keep widely-separated societies perpetually in step with one another. Even if the colonists and their descendants tried, the tyranny of light years and the forces for cultural differentiation, would make intercultural coordination most difficult. Furthermore, as the number of colonized star systems multiplied the problem for any one unit to keep track of all the others would progressively become more and more difficult to the point of impossibility.
But, biological diversification is the real threat to the unity of humanity, for by scattering through space our descendants could promote an explosive speciation. Biologists tell us that speciation occurs more readily in very small populations that have become geographically isolated from the main stock. While genetic change is resisted by large populations well adapted to their environment, favorable genetic mutations can easily gain a foothold in marginal geographic areas - where pressures for natural selection can be intense - and the spread quickly through the small populations isolated there.24
While this scenario of speciation has probably been repeated several times in our hominid past, for at least the last 50,000 years or so there is no evidence of major genetic change in humanity. Stephan Jay Gould estimates that the average Cro-Magnon, properly trained, could have handled computers with the best of us, and concludes that all we have accomplished since Cro-Magnon days has been the result of cultural evolution. The possibilities for rapid speciation by small, isolated groups inherent in the spread of Homo sapiens over the globe have been eliminated by the recent global mobility of people which has made the world community into one large population unit in which genes flow back and forth from continent to continent.25
The migration of our descendants into interstellar space, and the consequent scattering of small, discrete breeding population separated from one another by light years would once more set the stage for speciation in the human lineage.26 Furthermore, genetic change might be greatly accelerated by the highly ionizing radiation of space, and the selective pressures harsh space environments might impose. For example, habitats of significantly less than one gravity, and those significantly more than one gravity, would literally beg for biological adaptation. In addition, the systematic application to populations of advances in genetic engineering that would probably remain forbidden on earth and within the inner solar system at least would probably be more readily applied in interstellar space. When the nearest neighbours are light years away, groups desperate to adapt physiologically to an extreme environment, or anxious to enhance their intelligence, would feel much freer to experiment and develop their own desired version of humanity than would inhabitants of the closely-settled solar system.
So, by setting off in small groups to populate space, human evolution could be greatly accelerated. Nevertheless, however exotic this interstellar migration scenario might seem, the process of biological change would echo that followed by the exploratory founders of other species, including those of the hominid line. Typically, it is from the adventuresome minority, not the main stock, that evolutionary advance flows.
Biological change need not be limited, however, to a single speciation event, or a unilinear series of them. Space is not a single environment. It is a geocentric category we now use to refer to everything which is not on earth or within the atmosphere around it. By spreading into space we will be embarking on a process of adaptive radiation that will spread human-descended life as far as technology, or any limits placed by other intelligent life forms in the Galaxy, would allow. Just as the movement of fish onto land led to the multiplication of life forms on earth, so will this movement into interstellar space lead to an explosive radiation of intelligent life into the Galaxy. In the words of Freeman Dyson, to question whether or not we shall expand into space is really to ask: "Shall we be one species or a million?"2~
What exact forms will our interstellar descendants take? Will some evolve into creatures which are little more than huge brains? Will others regress physically - going back to the grasping feet of our arboreal ancestors to give them four hands for moving easily in zero or micro-gravity? Will others develop thick, armor-like skin for protection against radiation? Will still others attempt to combine computers and other manufactured components with biological forms? Or, as Freeman Dyson speculates, will some change themselves so radically as to become adapted to living in the vacuum of space of deriving their energy directly from starlight- allowing they and their descendants to leave planetary surfaces and the proximity of nurturing suns, and to radiate freely throughout space?28
I do not know, and I doubt that our evolutionary future can be predicted at all beyond the realization that humanity will speciate if we follow our urge to expand far into space. Though we may label our species as sapiens, and are beginning to be aware that we are not the culmination of all evolution, we are probably no more able to predict even the approximate course of our descendants' future developments than were those first apes to walk upright able to foretell what might follow from their change in habitat.
If, five million years ago, they could not have even dimly conceived the evolutionary consequences of their move from the forest to the grasslands, how can we--despite our newly found scientific knowledge--forecast all the evolutionary developments that will follow over the next five million years as our descendants disperse among the stars?
Notes
1. Etzioni 1964.
2. Arendt 1958:5,248.
3. Arendt 1958:1-2,10.
4. Sevastyanov et al. 1981.
5. Sevasryanoveral. 1981:26,45.
6. Finney 1987.
7. Darwin 1871:177; Isaac 1976; Johanson and White 1979; Canner al.
8. Johanson and Edey 1981:274; Tanner 1981.
9. Campbell 1982; Leakey et al. 1964; KaIb et al. 1982; Washburn 1967.
10. Cann et al. 1987; Stringer and Andrews 1988.
11. Allen er al. 1977; Reeves 1983.
12. Finney 1985a.
13. Parry 1974; Godinho 1965; Wallerstein 1974.
14. Eisely 1957:130-132; Gould 1977.
15. Lorenz 1971, Vol. 2:181.
16. Keegan and Diamond 1987.
17. Ehricke 1971, 1985.
18. Hartmann 1985.
19. Finney and Jones 1985; O'Neill 1977; Hartmann et al. 1984; Lovelock and Allaby 1984; McKay 1985.
20. Criswell 1985.
21. Godinho 1965; Wallerstein 1974.
22. Dyson 1979:118-126.
23. Jones and Finney 1985; Martin 1984.
24. Mayr 1954; Stanley 1979:206.
25. Gould 1982:83.
26. Valentine 1985.
27. Dyson 1981:234.
28. Jastrow 1981:162-168; Stableford 1984; Dysoh 1991.
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