GEOFFREY A. LANDIS
A View from Evolutionary Ecology
In the twenty-first century (as old-style humans counted the ages of the world), the intense pressure of evolutionary forces began to splinter the human race into subspecies.
First among these splinters was the set of humans who had control over technology. They had, by any older reckoning, nearly infinite power. We can call them potentates, for the potency of the tools they had at their whim. They were, for the most part, humans hooked into computers, with all of human technology available at their electronic fingertips.
The first law of ecology is that species radiate to fill all available niches, and technology was an available niche.
Most of the human race were not potentates, of course. The majority were ordinary people, living and working at meaningless jobs, struggling to eat and mate and raise a family and die in relative comfort.
The potentates were different. Hooked up to computers, nearly infinitely wealthy, they were for the most part antisocial—the computer hookups acted as a social force that selected humans with low requirements for interpersonal ties. By a century, massively parallel computational power was subsumed into biocomputational chips that were then refined until they were engineered directly into the genetics of those who could control the technology, and the potentates had become isolated from the old-style humans.
For the most part, the potentates were benevolent—or at least, indifferent—toward the humans of whom they were the unacknowledged masters. But not all. A few of them viewed the ordinary humans as disease. Engineered plagues, released by fringe elements, killed large portions of the world population. The less-fringe potentates engineered antiplague viruses to kill the engineered plagues, but each episode reduced the number of ordinary humans—and put pressure on them to adapt.
Huge numbers of the potentates simply immersed themselves into virtual realities, and by failing to breed, left the realm of ecology. Why do you need a real world when the virtual worlds are infinite in complexity, each deliberately designed for allure? Genetic diversity decreased as most potentates didn’t breed—but the ones that did breed produced dozens, in a few cases even thousands, of children.
New species adapted to fit into the human ecologies. (The first law of ecology again: adaptive radiation of species into available niches.) Molds, funguses, diseases, and cockroaches all adapted to fit into the human sphere, and humans learned to live with them. In a house, every clear surface became covered with a fine, downy coating of mold, and after a while, humans
adopted a mindset that this is right and natural—a surface bare of mold would be like a lawn bare of vegetation. (The second law: Species co-evolve to live together.)
Spaceflight was an obsession of a few of the potentates, and this led to a second radiation, this one purposeful. It was named the exodus. Ecologies were adapted for the Moon, for Mars.
The ecologies for the Moon were life-forms made of mostly silicon-based materials: silicon gels for flesh, silicon carbide bones, low-vapor-pressure fluorinated silicone oils instead of blood. Carbon was the limiting resource of the basic raw materials (silicones require carbon), and so mining life-forms were engineered to sieve carbon out of the low concentrations of the regolith, along with trace phosphorus, fluorine, and hydrogen. Call them photovoltaic trees, with roots that snaked down hundreds of meters into the lunar regolith, seeking the microscopic traces of carbonaceous chondritic material. The lunar life used DNA, but in a highly encapsulated form, redesigned to bond not to water molecules but to hydrogen bonds of engineered fluorinated silicones. The life simply froze solid during the 158-hour lunar nights, since energy storage turned out to be evolutionarily too expensive.
The Mars ecologies were more conventional, but still highly engineered. Even the definition of the word “biological” had to be somewhat stretched—is something alive if it has no biological precursors? If its DNA has been put together, base by base, by machines, and not inherited from ancestors?
Over the millennia, the life on the Moon and Mars devolved. The potentates had envisioned an ultimate stage where humans would fill the top predator role in their engineered ecology, but their plans never quite worked. The engineered ecology was not complex enough to support such a niche, and the human-equivalent sophonts (not by any stretch of biological definition could they actually be called human) failed to reproduce their numbers, and eventually simply died away. New species eventually adapted (that first law again) and radiated into all niches.
On the Earth, meanwhile, the nonhuman ecology crashed. Too many species had been wiped out, deliberately or as a side effect of other human activities, for the ecology to sustain itself. (The third law of ecology: The stability of an ecosystem is proportional to its species’ diversity.) This was a natural catastrophe: Ecology is a science of chaos, and ecological crashes happen every few tens of millions of years, give or take, with or without humans. It was hard, however, on those humans who were not potentates.
Over the course of about a millennium, humanity began further speciation. Other than the potentates, the remainder of humanity adapted into new forms that the potentates termed “hrats,” humans that had adapted to the plagues and unsuccessful extermination attempts of the potentates. As yet, the potentates and the hrats were still technically subspecies—they were still mutually fertile, when they chose to interbreed—but there was less and less cross-breeding occurring as the ecological niches of the hrats and the potentates diverged.
The potentates evolved slowly to be larger in size—they were at the top of the food chain, and there was no evolutionary pressure toward smaller size.
The various human hrat subspecies, on the other hand, evolved to be smaller—there was a tremendous pressure to use fewer resources, to be faster, more agile, more adaptable.
Over the course of a hundred millennia, the potentates evolved. Intelligence was no longer a selection force. The potentates had genetically engineered into their biological structure most of the technology that had put them at the top of the food chain, fiber-optic receptors for direct highbandwidth computer links, and microwave transceivers for low-bandwidth communications. What, exactly, did they need intelligence for? (The fourth law of ecology: Attributes not required by a species for survival will be lost.) Fat and happy (they engineered themselves to be happy) and with a low reproduction rate—at the top of their food chain with no natural enemies, they had to have a low reproduction rate, or they would kill their own ecology—they became, in all essential respects, dinosaurs. Huge and invulnerable, over the course of a quarter of a million years they lost the desire and the need to control the Earth.
The humans that the potentates had once denigrated as “hrats” live in a species-depleted, struggling ecology. The great ecological crash had resulted in a die-off, and the hrats lived in an ecology where survival of large animals was a difficulty. No global transportation systems—or at least none accessible to hrats—were left functional, so the hrats speciated, evolving separate forms on different continents and in different climatic zones on each continent. Like the potentates, the hrats also evolved away from intelligence—in the struggle for survival, traits that required a prolonged infancy and adolescence were too hard to maintain.
By a million years, there were no truly intelligent species on Earth.
Which is not to say that genus homo was extinct, far from it! With the extinction in the crash of all the species of large mammals (with the exception of dogs, preserved by the potentates), species of homo radiated to fill all of the open evolutionary niches. As the ecology recovered complexity, much of the diversity came from hominid species, now adapted to fill niches from grazers—hominid deer—to omnivores—hominid apes and pigs—and even some carnivore slots, hominid bears and jackals competing with the canine descendants to prey on squirrels and hominid deer.
In many ways, it was a beautiful and placid world: a new Eden.
One of the casualties of the great die-off was the extinction of a species of oceanic algae that had served a thermostatic function in the Earth’s overall heat balance by removing carbon dioxide from the atmosphere. The die-off of the oceanic algae and of a vast number of terrestrial plant species led to a buildup of atmospheric carbon dioxide and consequent warming of the Antarctic continent. The Earth settled into a second thermal equilibrium, a full interglacial period with no permanent ice features anywhere on the globe.
But climate eventually changes. A thousand-year period of unusually low volcanism stimulated a new algae to fit into a niche. This algae thrived in waters of low temperature and low carbon-dioxide saturation, and in the mindless way of single-celled organisms, went about producing these conditions.
The resultant reduction in greenhouse-effect warming triggered glaciation, at first only minor glaciation, but then increasing the spread of ice north across the warm valleys of Antarctica.
This glaciation resulted in a period of chaotic changes in the ecosystem, which opened a niche for intelligence to out-compete nonintelligent species. Following ancient laws of Darwin, intelligence arose in the savannas of Antarctica. (The fifth law of ecology: Evolution always occurs at the margin of an ecosystem.)
The new sophonts spread quickly from the Antarctic savanna to the northern arctic regions, and then in only a few millennia across the globe. Their first excursion into technology had been to discover the Antarctic coal deposits, one of the few fossil-fuel sources on the planet remaining in easily recoverable form. From there they developed a technology of ceramics and biopolymers that regarded metal as a pretty, but technologically unimportant, form of rock.
They quickly learned not to hunt the enormous and placid potentate beasts; while the beasts were not intelligent in any real sense, they were nevertheless still networked by microwave links (the new sophonts never did learn about microwaves), and an event experienced by any one of them was shared by all of the others, and never forgotten. With no visible weapons, no claws, no tusks, nevertheless the potentate beasts wielded invisible weapons, and a herd of potentates, acting together as a phased array of microwave beams, could melt cities. Leave them alone, the sophonts found, and they will leave you alone.
The sophonts never had the ambiguous benefit of believing that they had been the only intelligent race on Earth; even a million years after the last cities of Homo sapiens had collapsed into rubble, they lived in a world of abundant and incomprehensible artifacts, and it was clear that they had lived in a world that once had been inhabited by a world-treading race that had leveled mountains and built tremendous cities.
For the most part, the artifacts they found had little meaning. Cities they understood, but having never discovered electricity, the remnants of printed circuit boards were meaningless, and while buried fiber-optic cables were obviously a technology for piping light, the purpose for doing so was obscure. But with their own technology that owed little or nothing to Homo sapiens, they developed factories and eventually spaceflight. The enormous space artifacts of the era of the potentates, pinwheels and staging stations, had long since decayed from orbit. The geosynchronous-orbit communications satellites remained as curiosities to be retrieved and puzzled over, but never understood.
They never traveled as far as the Moon, and with no knowledge of radio and no requirements for communications satellites, their era of spaceflight was a brief one. There would have been nothing to find of any interest on the Moon in any case; the lunar ecosystem had died back to a sparse ecology consisting of little more than the great photovoltaic trees, two species of mold, and a few dozen species of small mobile life that filled the niche of crawling insects.
Over the course of a hundred thousand years, their civilization grew stagnant and died, and less than a half-million years later, the Earth had no trace of them except for a heritage of cryptic ceramic artifacts, sharing the ground with the artifacts of Homo sapiens.
Over the next twenty million years, two more species that could arguably be called intelligent arose. Neither achieved spaceflight. Although the second of the two species lasted for a period of five million years, eventually they succeeded in adjusting the world to suit them, and reached the point where they no longer had a need for intelligence.
The planet Mars has no magnetic field and is therefore subject to a withering bullet-storm of solar and galactic cosmic radiation. In designing forms of life to survive on Mars, the potentates had engineered a more robust form of DNA, with quintuply redundant information storage, with error-correction coding at every stage of reproduction and cell growth. It had not been their actual intent to design an ecology to be immune from evolution, but that had been the result.
Nevertheless, eventually error-correction codes fail. The quintuply redundant information storage corrupted to merely quadruple redundancy, and then slightly faster corrupted down to triple, and faster yet to double, and single redundant. In fifty million years, evolution started up on Mars.
It took well over a hundred million years before the Mars life evolved to intelligence, and from there only a few millennia before they invented spaceships. They had, of course, no notion of their terrestrial roots.
The sixth law of ecology tells us that when isolated populations are brought into contact, the more robust forms quickly drive out the less robust. In this case, the harsh conditions on Mars had made the Martian life-forms highly robust. The Earth life-forms really didn’t have a chance. The contact with Mars was a K-T level event, and like the end of the Ternary period, it resulted in rapid evolutionary radiation in all directions. And then history gets seriously weird.
But this is a history of the various human species, and so the history of what happened after the return of the Martians must be beyond the bounds of this story.
—for Olaf Stapledon