Talkin' 'Bout An Evolution

Talk about unimaginative. After the radically unconventional attacks on Sept. 11, the United States government strikes back in the most predictable way possible, by bombing Afghanistan from the air. Instead of studying an obsolete military playbook to plan the U.S. response, we might turn to the steady principles of ecology: After all, organisms have been living with each other on Earth for more than 3 billion years, about 300,000 times longer than humans have been living in fortified cities.

The creatures that preceded us on this planet encountered plenty of threats to their survival: ice ages, new predators, and the disappearance of their accustomed prey, to name a few. Depending on how well they could adapt, some species persisted; others died off.

Human beings, of course, are also subject to evolutionary forces. But humans don't rely only on biological selection; we can direct our own cultural and political evolution to improve our odds of survival. In the wake of last month's attacks, that process will challenge us to reflect on our society's weaknesses and strengths, and to consider our assailants' capabilities and motivations just as though they were other organisms sharing our habitat -- which, in fact, they are.

Take, for example, the process by which plants and plant-eaters evolve in step with each other. Herbivores begin to munch on tender plants, and plants respond by developing defenses -- poisons secreted in their flesh, thorns on their stems, tall trunks that bear their foliage beyond the reach of deer. But the herbivores don't let the grass grow under their feet. The same evolutionary mechanism allows them to circumvent the plants' defenses. Some browsing animals, like koalas, use their claws to climb high into the canopy and graze uninterrupted on eucalyptus leaves. The monarch butterfly larva has learned to tolerate the toxic sap of the milkweed plant, even storing the plant's bitter glycosides in its own tissues as a deterrent to predatory birds.

We have observed some of these adaptations in our own time. As farmers have applied insecticides to their crops, they have inadvertently selected for bugs that are resistant to these chemical poisons. To preserve the effectiveness of chemical sprays, agricultural companies must stay a step ahead of the insects' adaptations to toxins being used against them. Similar cycles have bred strains of bacteria that resist antibiotics.

In the geopolitical arena, the same processes are writ large. During the decades following World War II, the United States established itself as the world's preeminent military power, able to subdue any nation on the battlefield. In response, its opponents adapted by choosing other arenas for confrontation. In Vietnam, for instance, the Viet Cong showed that they could defend their homeland against a superior military force by using guerrilla war techniques.

Anyone wanting to mount an offensive against the United States, however, would need different tactics. A frontal military attack against U.S. forces would be futile, and would guarantee overwhelming retaliation. But the smaller, more easily concealed attack cells used by the Sept. 11 terrorists are much harder to repel. Moreover, it is difficult to determine with certainty where terrorist attacks originate, making it harder to retaliate effectively against them.

In part, strength and vulnerability are a matter of scale. A grizzly bear is less likely to be crippled by competing carnivores like the fox and weasel than by disease-carrying parasites such as lice and ticks, against which its sharp claws carve no defense. Likewise, the bombings that began this week may determine whether the U.S. military machine is any more effective against these terrorists than a .22 against a cloud of buzzing tsetse flies.

We can also anticipate that new defensive measures will breed new countermeasures. A month ago, the suicidal diversion of commercial jetliners proved to be a hideously effective way to spread destruction and panic in the U.S., as the terrorists apparently wanted to do. Today, that tactic might not be as successful. But much like pests adjusting to the application of a new insecticide, terrorists can steer clear of invigorated airport security measures and adopt other tactics. When air traffic becomes more secure, terrorists may direct their assaults at other spots on our country's soft underbelly -- nuclear power plants, public water supplies, subway ventilation systems. A modern Maginot Line of security guards at airports won't defend us against any such strikes.

Come Together

If ecology teaches that each of our parries will in turn invite a new strike, does that mean that more terrorist strikes are inevitable? First, we must realize that more players are involved than just the United States and its terrorist foes. In ecosystems, any species is affected not just by its own interactions with its fellows, but also by their interactions with each other. Sea urchins eat kelp, but otters devour urchins. Thus, the presence of a healthy otter population makes possible the proliferation of vast kelp forests and the schools of fish that inhabit them.

Similarly, our security doesn't depend only on our police apparatus, but also on the needs and motives of the other people with whom we share this planet. American citizens may be ignorant bystanders to conflict within the Muslim world, but we are not exempt from its fallout. Severe imbalances of economic and political power across the globe -- while in no way justifying the attacks -- can breed acts of desperation against which military defense is difficult if not impossible.

Now that the events of Sept. 11 have alerted us to these dangers, our society can attempt to evolve and become fitter in the face of the terrorist threat. Two decades ago, the Pentagon commissioned Amory and Hunter Lovins to study U.S. vulnerability to attack on centralized energy facilities such as pipelines and power plants; their conclusions were published in 1981 as Brittle Power: Energy Strategy for National Security. Had the United States followed those recommendations to reduce our dependence on nuclear energy and fossil fuels, the American heartland would present fewer tempting targets. The United States might also have felt less pressure to intervene in the oil-rich Persian Gulf in 1991, a move that reportedly turned Osama bin Laden against his former American allies.

In contrast, other measures may actually reduce our fitness to survive. Oil-drilling on the Arctic frontier would draw one more supply line across the thinly patrolled Alaskan hinterland, leaving more of our energy supply vulnerable to terrorist attack. Those who propose to curtail civil liberties -- expanding police powers for surveillance, search and seizure -- make us vulnerable to a different kind of crisis by threatening to undermine American values in a quest for stability. That path would turn society's defenses against itself, in a kind of auto-immune disorder of the body politic.

In the aftermath of Sept. 11, we must choose our next steps carefully, or risk extinction. American society may prove fit enough to survive, perish like the dinosaurs, or transform itself into a beast that bears little resemblance to the America we once knew. The survival of our society and perhaps even our species depends on the wisdom of our national response.