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Out of Control by Kevin Kelly
Chapter Four: Assembling Complexity
Posted here with permission. The full text of the book is available on the author's website.

outofcontrol-sm.gif Biology: the future of machines

As an autumn gray settles, I stand in the middle of one of the last wildflower prairies in America. A slight breeze rustles the tan grass. I close my eyes and say a prayer to Jesus, the God of rebirth and resurrection. Then I bend at the waist, and with a strike of a match, I set the last prairie on fire. It burns like hell.

"The grass of the field alive today is thrown into the oven tomorrow," says the rebirth man. The Gospel passage comes to mind as an eight-foot-high wall of orange fire surges downwind crackling loudly and out of control. The heat from the wisps of dead grass is terrific. I am standing with a flapping rubber mat on a broom handle trying to contain the edges of the wall of fire as it marches across the buff-colored field. I remember another passage: "The new has come, the old is gone."

While the prairie burns, I think of machines. Gone is the old way of machines; come is the reborn nature of machines, a nature more alive than dead.

I've come to this patch of fire-seared grass because in its own way this wildflower field is another item of human construction, as I can explain in a moment. The burnt field makes a case that life is becoming manufactured, just as the manufactured is becoming life, just as both are becoming something wonderful and strange.

The future of machines lies in the tangled weeds underfoot. Machines have steadily plowed under wildflower prairies until none are left except the tiny patch I'm standing in. But in a grand irony, this patch holds the destiny of machines, for the future of machines is biology.

My guide to the grassy inferno is Steve Packard, an earnest, mid-thirties guy, who fondles bits of dry weeds-their Latin names are intimately familiar to him-as we ramble through the small prairie. Almost two decades ago, Packard was captured by a dream he couldn't shake. He imagined a suburban dumping ground blooming again in its original riotous prairie-earth colors, an oasis of life giving soulful rest to harried cosmopolitans. He dreamt of a prairie gift that would "pay for itself in quality-of-life dollars," as he was fond of telling supporters. In 1974 Packard began working on his vision. With the mild help of skeptical conservation groups, he began to recreate a real prairie not too far from the center of the greater city of Chicago.

Packard knew that the godfather of ecology, Aldo Leopold, had successfully recreated a prairie of sorts in 1934. The University of Wisconsin, where Leopold worked, had purchased an old farm, called the Curtis place, to make an arboretum out of it. Leopold convinced the University to let the Curtis farm revert to prairie again. The derelict farm would be plowed one last time, then sown with disappearing and all but unknown prairie seeds, and left to be.

This simple experiment was not undoing the clock; it was undoing civilization.

Until Leopold's innocent act, every step in civilization had been another notch in controlling and retarding nature. Houses were designed to keep nature's extreme temperatures out. Gardens contrived to divert the power of botanical growth into the tame artifacts of domesticated crops. Iron mined in order to topple trees for lumber.

Respites from this march of progress were rare. Occasionally a feudal lord reserved a wild patch of forest from destruction for his game hunting. Within this sanctuary a gamekeeper might plant wild grain to attract favored animals for his lord's hunt. But until Leopold's folly no one had ever deliberately planted wilderness. Indeed, even as Leopold oversaw the Curtis project, he wondered if anyone could plant wilderness. As a naturalist, he figured it must be largely a matter of letting nature reclaim the spot. His job would be protecting whatever gestures nature made. With the help of colleagues and small bands of farm boys hired by the Civilian Conservation Corps during the Depression, Leopold nursed 300 acres of young emerging prairie plants with buckets of water and occasional thinning of competitors for the first five years.

The prairie plants flourished; but so did the nonprairie weeds. Whatever was carpeting this meadow, it was not the prairie that once did. Tree seedlings, Eurasian migrants, and farm weeds all thrived along with the replanted prairie species. Ten years after the last plowing, it was evident to Leopold that the reborn Curtis prairie was only a half-breed wilderness. Worse, it was slowly becoming an overgrown weedy lot. Something was missing.

A key species, perhaps. A missing species which once reintroduced, would reorder the whole community of ecology of plants. In the mid-1940s that species was identified. It was a wary animal, once ubiquitous on the tall grass prairies, that roamed widely and interacted with every plant, insect, and bird making a home over the sod. The missing member was fire.

Fire made the prairie work. It hatched certain fire-triggered seeds, it eliminated intruding tree saplings, it kept the fire-intolerant urban competitors down. The rediscovery of fire's vital function in tall grass prairie ecology coincided with the rediscovery of fire in the role of almost all the other ecologies in North America. It was a rediscovery because fire's effects on nature had been recognized and used by the aboriginal researchers of the land. The ubiquitous prevalence of fire on the pre-whiteman prairie was well documented by European settlers.

While evident to us now, the role of fire as a key ingredient of the prairie was not clear to ecologists and less clear to conservationists, or what we would now call environmentalists. Ironically, Aldo Leopold, the greatest American ecologist, argued fiercely against letting wildfire burn in wilderness. He wrote in 1920, "The practice of [light-burning] would not only fail to prevent serious fires but would ultimately destroy the productivity of the forests on which western industries depend for their supply of timber." He gave five reasons why fire was bad, none of them valid. Railing against the "light-burning propagandists," Leopold wrote, "It is probably a safe prediction to state that should light-burning continue for another fifty years, our existing forest areas would be further curtailed to a very considerable extent."

A decade later, when more was known about the interdependencies of nature, Leopold finally conceded the vital nature of organic fire. When he reintroduced fire into the synthetic plots of the Wisconsin field grass arboretum, the prairie flourished like it had not for centuries. Species that were once sparse started to carpet the plots.

Still, even after 50 years of fire and sun and winter snows, the Curtis prairie today is not completely authentic in the diversity of its members. Around the edges especially, where ecological diversity is usually the greatest, the prairie suffers from invasions of monopolistic weeds-the same few ones that thrive on forgotten lots.

The Wisconsin experiment proved one could cobble together a fair approximation of a prairie. What in the world would it take to make a pure prairie, authentic in every respect, an honest-to-goodness recreated prairie? Could one grow a real prairie from the ground up? Is there a way to manufacture a self-sustaining wilderness?

Restoring a prairie with fire and oozy seeds

In the fall of 1991, I stood with Steve Packard in one of his treasures-what he called a "Rembrandt found in the attic"-at the edge of a suburban Chicago woods. This was the prairie we would burn. Several hundred acres of rustling, wind-blown grass swept over our feet and under scattered oak trees. We swam in a field far richer, far more complete, and far more authentic than Leopold had seen. Dissolved into this pool of brown tufts were hundreds of uncommon species. "The bulk of the prairie is grass," Packard shouted to me in the wind, "but what most people notice is the advertising of the flowers." At the time of my visit, the flowers were gone, and the ordinary-looking grass and trees seemed rather boring. That "barrenness" turned out to be a key clue in the rediscovery of an entire lost ecosystem.

To arrive at this moment, Packard spent the early 1980s locating small, flowery clearings in the thickets of Illinois woods. He planted prairie wildflower seeds in them and expanded their size by clearing the brush at their perimeters. He burnt the grass to discourage nonnative weeds. At first he hoped the fire would do the work of clearing naturally. He would let it leap from the grass into the thicket to burn the understory shrubs. Then, because of the absence of fuel in the woods, the fire would die naturally. Packard told me, "We let the fires blast into the bush as far as they would go. Our motto became 'Let the fires decide.' "

But the thickets would not burn as he hoped, so Packard and his crews interceded with axes in hand and physically cleared the underbrush. Within two years, they were happy with their results. Thick stands of wild rye grass mingled with yellow coneflower in the new territory. The restorers manually hacked back the brush each season and planted the choicest prairie flower seed they could find.

But by the third year, it was clear something was wrong. The plantings were doing poorly in the shade, producing poor fuel for the season's fires. The grasses that did thrive were not prairie species; Packard had never seen them before. Gradually, the replanted areas reverted to brush.

Packard began to wonder if anyone, including himself, would go through the difficulties of burning an empty plot for decades if they had nothing to show for it. He felt yet another ingredient must be missing which prevented a living system from snapping together. He started reading the botanical history of the area and studying the oddball species.

When he identified the unknown species flourishing so well in the new oak-edge patches, he discovered they didn't belong to a prairie, but to a savanna ecosystem-a prairie with trees. Researching the plants that were associated with savanna, Packard soon came up with a list of other associated species-such as thistles, cream gentians, and yellow pimpernels-that he quickly realized peppered the fringes of his restoration sites. Packard had even found a blazing star flower a few years before. He had brought the flowering plant to a university expert because varieties of blazing star defy nonexpert identification. "What the heck is this?" he'd asked the botanist. "It's not in the books, it's not listed in the state catalogue of species. What is it?" The botanist had said, "I don't know. It could be a savanna blazing star, but there aren't any savannas here, so it couldn't be that. Don't know what is." What one is not looking for, one does not see. Even Packard admitted to himself that the unusual wildflower must have been a fluke, or misidentified. As he recalls, "The savanna species weren't what I was looking for at first so I had sort of written them off."

But he kept seeing them. He found more blazing star in his patches. The oddball species, Packard was coming to realize, were the main show of the clearings. There were many other species associated with savannas he did not recognize, and he began searching for samples of them in the corners of old cemeteries, along railway right-of-ways, and old horse paths-anywhere a remnant of an earlier ecosystem might survive. Whenever he could, he collected their seed.

An epiphany of sorts overtook Packard when he watched the piles of his seed accumulate in his garage. The prairie seed mix was dry and fluffy-like grass seed. The emerging savanna seed collection, on the other hand, was "multicolored handfuls of lumpy, oozy, glop," ripe with pulpy seeds and dried fruits. Not by wind, but by animals and birds did these seeds disperse. The thing-the system of coevolved, interlocking organisms-he was seeking to restore was not a mere prairie, but a prairie with trees: a savanna.

The pioneers in the Midwest called a prairie with trees a "barren." Weedy thickets and tall grass grew under occasional trees. It was neither grassland nor forest-therefore barren to the early settlers. An almost entirely different set of species kept it a distinct biome from the prairie. The savanna barrens were particularly dependent on fire, more so than the prairies, and when farmers arrived and stopped the fires, the barrens very quickly collapsed into a woods. By the turn of this century the barrens were almost extinct, and the list of their constituent species hardly recorded. But once Packard got a "search image" of the savanna in his mind, he began to see evidence of it everywhere.

Packard sowed the mounds of mushy oddball savanna species, and within two years the fields were ablaze with rare and forgotten wildflowers: bottlebrush grass, blue-stem goldenrod, starry champion, and big-leafed aster. In 1988, a drought shriveled the non-native weeds as the reseeded natives flourished and advanced. In 1989, a pair of eastern bluebirds (which had not been seen in the county for decades) settled into their familiar habitat-an event that Packard took as "an endorsement." The university botanists called back. Seems like there were early records of savanna blazing star in the state. The biologists were putting it on the endangered list. Oval milkweed somehow returned to the restored barren although it grows nowhere else in the state. Rare and endangered plants like the white-fringed orchid and a pale vetchling suddenly sprouted on their own. The seed might have lain dormant-and between fire and other factors found the right conditions to hatch-or been brought in by birds such as the visiting blue birds. Just as miraculously, the silvery-blue butterfly, which had not been seen anywhere in Illinois for a full decade, somehow found its way to suburban Chicago where its favorite food, vetchling, was now growing in the emerging savanna.

"Ah," said the expert entomologists. "The classic savanna butterfly is Edwards hairstreak. But we don't see any. Are you sure this is a savanna?" But by the fifth year of restoration, the Edwards hairstreak butterfly was everywhere on the site.

If you build it, they will come. That's what the voice said in the Field of Dreams. And it's true. And the more you build it, the more that come. Economists call it the "law of increasing returns"-the snowballing effect. As the web of interrelations is woven tighter, it becomes easier to add the next piece.

Random paths to a stable ecosystem

Yet there was still an art to it. As Packard knotted the web, he noticed that it mattered what order he added the pieces in. And he learned that other ecologists had discovered the same thing. A colleague of Leopold had found that he got closer to a more authentic prairie by planting prairie seed in a weedy field, rather than in a newly plowed field, as Leopold had first done. Leopold had been concerned that the aggressive weeds would strangle the wildflowers, but a weedy field is far more like a prairie than a plowed field. Some weeds in an old weedy lot are latecomers, and a few of these latecomers are prairie members; their early presence in the conversion quickens the assembly of the prairie system. But the weeds that immediately sprout in a plowed, naked field are very aggressive, and the beneficial late-arriving weeds come into the mix too late. It's like having the concrete reinforcement bars arrive after you've poured the cement foundation for your house. Succession is important.

Stuart Pimm, an ecologist at the University of Tennessee, compares succession paths-such as the classic series of fire, weed, pine, broadleaf trees-to well-rehearsed assembly sequences that "the players have played many times. They know, in an evolutionary sense, what the sequence is." Evolution not only evolves the functioning community, but it also finely tunes the assembly process of the gathering until the community practically falls together. Restoring an ecosystem community is coming at it from the wrong side. "When we try to restore a prairie or wetland, we are trying to assemble an ecosystem along a path that the community has no practice in," says Pimm. We are starting with an old farm, while nature may have started with a glacial moraine ten thousand years ago. Pimm began asking himself: Can we assemble a stable ecosystem by taking in the parts at random? Because at random was exactly how humans were trying to restore ecosystems.

In a laboratory at the University of Tennessee, ecologists Pimm and Jim Drake had been assembling ingredients of microecosystems in different random orders to chart the importance of sequence. Their tiny worlds were microcosms. They started with 15 to 40 different pure strains of algae and microscopic animals, and added these one at a time in various combinations and sequences to a large flask. After 10 to 15 days, if all went well, the aquatic mixture formed a stable, self-reproducing slime ecology-a distinctive mix of species surviving off of each other. In addition Drake set up artificial ecologies in aquaria and in running water for artificial stream ecologies. After mixing them, they let them run until they were stable. "You look at these communities and you don't need to be a genius to see that they are different," Pimm remarks. "Some are green, some brown, some white. But the interesting thing is that there is no way to tell in advance which way a particular combination of species will go. Like most complex systems, you have to set them up and run them to find out."

It was also not clear at the start whether finding a stable system would be easy. A randomly made ecosystem was likely, Pimm thought, "to just wander around forever, going from one state to the next and back again without ever coming to a persistent state." But the artificial ecosystems didn't wander. Instead, much to their surprise, Pimm found "all sorts of wonderful wrinkles. For one, these random ecosystems have absolutely no problem in stabilizing. Their most common feature is that they always come to a persistent state, and typically it's one state per system."

It was very easy to arrive at a stable ecosystem, if you didn't care what system you arrived at. This was surprising. Pimm said, "We know from chaos theory that many deterministic systems are exquisitely sensitive to initial conditions-one small difference will send it off into chaos. This stability is the opposite of that. You start out in complete randomness, and you see these things assemble towards something that is a lot more structured than you had any reason to believe could be there. This is anti-chaos."

To complement their studies in vitro, Pimm also set up experiments "in silico"-simplified ecological models in a computer. He created artificial "species" of code that required the presence of certain other species to survive, and also gave them a pecking order so that species B might drive out species A if and when the population of B reached a certain density. (Pimm's models of random ecologies bear some resemblance to Stuart Kauffman's models of random genetic networks; see chapter 20). Each species was loosely interconnected to the others in a kind of vast distributed network. Running thousands of random combinations of the same list of species, Pimm mapped how often the resulting system would stabilize so that minor perturbations, such as introductions or removals of a few species, would not destabilize the collective mix. His results mirrored the results from his bottled living microworlds.

In Pimm's words, the computer models showed that "with just 10 to 20 components in the mix, the number of peaks [or stabilities] may be in the tens, twenties or hundreds. And if you play the tape of life again, you get to a different peak." In other words, after dropping in the same inventory of species, the mess headed toward a dozen final arrangements, but changing the entry sequence of even one of the species was enough to divert the system from one of the end-points to another. The system was sensitive to initial conditions, but it was usually attracted to order.

Pimm saw Packard's work in restoring the Illinois prairie/savanna as validating his findings: "When Packard first tried to assemble the community, it didn't work in the sense that he couldn't get the species he wanted to stick and he had a lot of trouble taking out things he didn't want. But once he introduced the oddball, though proper, species it was close enough to the persistent state that it easily moved there and will probably stay there."

Pimm and Drake discovered a principle that is a great lesson to anyone concerned about the environment, and anyone interested in building complex systems. "To make a wetland you can't just flood an area and hope for the best," Pimm told me. "You are dealing with systems that have assembled over hundreds of thousand, or millions of years. Nor is compiling a list of what's there in terms of diversity enough. You also have to have the assembly instructions."

How to do everything at once

Steve Packard set out to extend the habitat of authentic prairie. On the way he resurrected a lost ecosystem, and perhaps acquired the assembly instructions for a savanna. Working in an ocean of water instead an ocean of grass, David Wingate in Bermuda set out thirty years ago to nurse a rare species of shorebird back from extinction. On the way, he recreated the entire ecology of a subtropical island, and illuminated a further principle of assembling large functioning systems.

The Bermuda tale involves an island suffering from an unhealthy, ad hoc, artificial ecosystem. By the end of World War II, Bermuda was ransacked by housing developers, exotic pests, and a native flora wrecked by imported garden species. The residents of Bermuda and the world's scientific community were stunned, then, in 1951 by the announcement that the cahow-a gull-size seabird-had been rediscovered on the outer cliffs of the island archipelago. The cahow was thought to be extinct for centuries. It was last seen in the 1600s, around the time the dodo had gone extinct. But by a small miracle, a few pairs of breeding cahows hung for generations on some remote sea cliffs in the Bermuda archipelago. They spent most of their life on water, only coming ashore to nest underground, so they went unnoticed for four centuries.

As a schoolboy with a avid interest in birds, David Wingate was present in 1951 when a Bermudan naturalist succeeded in weaseling the first cahow out of its deep nesting crevice. Later, Wingate became involved in efforts to reestablish the bird on a small uninhabited island near Bermuda called Nonsuch. He was so dedicated to the task that he moved-newly married-to an abandoned building on the uninhabited, unwired outer island.

It quickly became apparent to Wingate that the cahow could not be restored unless the whole ecosystem of which it was part was also restored. Nonsuch and Bermuda itself were once covered by thick groves of cedar, but the cedars had been wiped out by an imported insect pest in a mere three years between 1948 and 1952. Only their huge white skeletons remained. In their stead were a host of alien plants, and on the main island, many tall ornamental trees that Wingate was sure would never survive a once-in-fifty-year hurricane.

The problem Wingate faced was the perennial paradox that all whole systems makers confront: where do you start? Everything requires everything else to stay up, yet you can't levitate the whole thing at once. Some things have to happen first. And in the correct order.

Studying the cahows, Wingate determined that their underground nesting sites had been diminished by urban sprawl and subsequently by competition with the white-tailed tropicbird for the few remaining suitable sites. The aggressive tropicbird would peck a cahow chick to death and take over the nest. Drastic situations require drastic measures, so Wingate instituted a "government housing program" for the cahow. He built artificial nest sites-sort of underground birdhouses. He couldn't wait until Nonsuch reestablished a forest of trees, which tip slightly in hurricanes to uproot just the right-sized crevice, too small for the tropic bird to enter, but just perfect for the cahow. So he created a temporary scaffolding to get one piece of the puzzle going.

Since he needed a forest, he planted 8,000 cedar trees in the hope that a few would be resistant to the blight, and a few were. But the wind smothered them. So Wingate planted a scaffold species-a fast-growing non-native evergreen, the casuarinas-as a windbreak around the island. The casuarinas grew rapidly, and let the cedars grow slowly, and over the years, the better-adapted cedars displaced the casuarinas. The resown forest made the perfect home for a night heron which had not been seen on Bermuda for a hundred years. The heron gobbled up land crabs which, without the herons, had become a pest on the islands. The exploded population of land crabs had been feasting on the succulent sprouts of wetland vegetation. The crab's reduced numbers now allowed rare Bermudan sedges to grow, and in recent years, to reseed. It was like the parable of "For Want of a Nail, The Kingdom Was Lost," but in reverse: By finding the nail, the kingdom was won. Notch by notch, Wingate was reassembling a lost ecosystem.

Ecosystems and other functioning systems, like empires, can be destroyed much faster than they can be created. It takes nature time to grow a forest or marsh because even nature can't do everything at once. The kind of assistance Wingate gave is not unnatural. Nature commonly uses interim scaffolding to accomplish many of her achievements. Danny Hillis, an artificial intelligence expert, sees a similar story in the human thumb as a platform for human intelligence. A dexterous hand with a thumb-grasp made intelligence advantageous (for now it could make tools), but once intelligence was established, the hand was not as important. Indeed, Hillis claims, there are many stages needed to build a large system that are not required once the system is running. "Much more apparatus is probably necessary to exercise and evolve intelligence than to sustain it," Hillis wrote. "One can believe in the necessity of the opposable thumb for the development of intelligence without doubting a human capacity for thumbless thought."

When we lie on our backs in an alpine meadow tucked on the perch of high mountains, or wade into the mucky waters of a tidal marsh, we are encountering the "thumbless thoughts" of nature. The intermediate species required to transform the proto-meadow into a regenerating display of flowers are now gone. We are only left now with the thought of flowers and not the helpful thumbs that chaperoned them into being.

The Humpty Dumpty challenge

You may have heard the heartwarming account of "The Man Who Planted Trees and Grew Happiness." It's about how a forest and happiness were created out of almost nothing. The story is told by a young European man who hikes into a remote area of the Alps in 1910.

The young man wanders into a windy, treeless region, a harsh place whose remaining inhabitants are a few mean, poor, discontented charcoal burners huddled in a couple of dilapidated villages. The hiker meets the only truly happy inhabitant in the area, a lone shepherd hermit. The young man watches in wonder as the hermit wordlessly and idiotically spends his days poking acorns one by one into the moonscape. Every day the silent hermit plants 100 acorns. The hiker departs, eager to leave such desolation, only to return many years later by accident, after the interruption of World War I. He now finds the same village almost unrecognizable in its lushness. The hills are flush with trees and vegetation, brimming with streams, and full of wildlife and a new population of content villagers. Over three decades the hermit had planted 90 square miles thick with oak, beech, and birch trees. His single-handed work-a mere nudge in the world of nature-had remodeled the local climate and restored the hopes of many thousands of people.

The only unhappy part of the story is that it is not true. Although it has been reprinted as a true story all over the world, it is, in fact, a fantasy written by a Frenchman for Vogue magazine. There are, however, genuine stories of idealists recreating a forest environment by planting trees in the thousands. And their results confirm the Frenchman's intuition: tiny plants grown on a large scale can divert a local ecosystem in a positive loop of increasing good.

As one true example, in the early 1960s, an eccentric Englishwoman, Wendy Campbell-Purdy, journeyed to North Africa to combat the encroaching sand dunes by planting trees in the desert. She planted a "green wall" of 2,000 trees on 45 acres in Tiznit, Morocco. In six years time, the trees had done so well, she founded a trust to finance the planting of 130,000 more trees on a 260-acre dump in the desert wastes at Bou Saada, Algeria. This too took off, creating a new minihabitat that was suitable for growing citrus, vegetables, and grain.

Given a slim foothold, the remarkable latent power in interconnected green things can launch the law of increasing returns: "Them that has, gets more." Life encourages an environment that encourages yet more life. On Wingate's island the presence of herons enables the presence of sedges. In Packard's prairie the toehold of fire enables the existence of wildflowers which enable the existence of butterflies. In Bou Saada, Algeria, some trees alter the climate and soil to make them fit for more trees. More trees make a space for animals and insects and birds, which prepare a place for yet more trees. Out of acorns, nature makes a machine that provides a luxurious home for people, animals, and plants.

The story of Nonsuch and the other forests of increasing returns, as well as the data from Stuart Pimm's microcosms overlap into a powerful lesson that Pimm calls the Humpty Dumpty Effect. Can we put the Humpty Dumpty of a lost ecosystem together again? Yes, we can if we have all the pieces. But we don't know if we do. There may be chaperone species that catalyze the assembly of an ecosystem in some early stage-the thumb for intelligence-that just aren't around the neighborhood anymore. Or, in a real tragedy, a key scaffold species may be globally extinct. One could imagine a hypothetical small, prolific grass essential to creating the matrix out of which the prairie arose, which was wiped out by the last ice age. With it gone, Humpty Dumpty can't be put back together again. "Keep in mind you can't always get there from here," Pimm says.

Packard has contemplated this sad idea. "One of the reasons the prairie may never be fully restored is that some parts are forever gone. Perhaps without the megaherbivores like the mastodon of old or even the bison of yesteryear, the prairie won't come back." Even more scary is yet another conclusion of Pimm's and Drake's work: that it is not just the presence of the right species, in the right order, but the absence of the right species at the right time as well. A mature ecology may be able to tolerate species X easily; but during its assembly, the presence of species X will divert the system onto some other path leading toward a different ecosystem. "That's why," Packard sighs, "it may take a million years to make an ecosystem." Which species now rooted on Nonsuch island or dwelling in the Chicago suburbs might push the reemerging savanna ecosystem away from its original destination?

The rule for machines is counterintuitive but clear: Complex machines must be made incrementally and often indirectly. Don't try to make a functioning mechanical system all at once, in one glorious act of assembly. You have to first make a working system that serves as a platform for the system you really want. To make a mechanical mind, you need to make the equivalent of a mechanical thumb-a lateral approach that few appreciate. In assembling complexity, the bounty of increasing returns is won by multiple tries over time-a process anyone would call growth.

Ecologies and organisms have always been grown. Today computer networks and intricate silicon chips are grown too. Even if we owned the blueprints of the existing telephone system, we could not assemble a replacement as huge and reliable as the one we had without in some sense recapitulating its growth from many small working networks into a planetary web.

Creating extremely complex machines, such as robots and software programs of the future, will be like restoring prairies or tropical islands. These intricate constructions will have to be assembled over time because that is the only way to make sure they work from top to bottom. Unripe machinery let out before it is fully grown and fully integrated with diversity will be a common complaint. "We ship no hardware before its time," will not sound funny before too long.