Most people can be forgiven for ignoring the threat posed by nuclear weapons. It might seem surprising, but we have been preprogrammed by our own evolutionary history to engage in such ignorance. The nuclear age is just a tiny blip tacked on to our very recent phylogenetic past, so when it comes to the greatest of all risks to human survival, we are more threatened by the instincts we lack than by those we possess.
And yet, we are genuinely threatened by those weapons we possess, which the United States government is planning to upgrade at an estimated cost of $1 trillion over the next three decades. Partly in response, on Thursday the Bulletin of the Atomic Scientists reset its iconic Doomsday Clock from five minutes to midnight to three minutes and counting.
How does evolution create our ignorance, thereby adding to our danger? Because its two forms — biological and cultural — are disconnected, and so are we, from our own self-interest.
Homo sapiens is the product of biological evolution — a painfully slow Darwinian process — yet we are simultaneously enmeshed in its cultural counterpart, a Lamarckian phenomenon which, by contrast, is blindingly fast and proceeds under its own rules. We have one foot thrust into the cultural present and the other stuck in our biological past.
Individuals, after all, do not evolve in the Darwinian sense; only populations and lineages do. And they are shackled to the realities of genetics and reproduction, since organic evolution is a process whereby gene frequencies change over time. Accordingly, generations are required for even the smallest evolutionary step.
By contrast, cultural evolution is astoundingly rapid. Acquired characteristics can be “inherited,” a la Lamarck, in hours or days, then passed along to other individuals, modified yet again before being picked up or dropped altogether. For example, in just a few decades (less than an instant in biological time), personal computers were developed, proliferated and modified. If they had “evolved” by Darwinian, biological means, as a favorable mutation to be promoted in one or even a handful of individuals, there would currently be only a dozen or so computer users instead of billions.
Just a superficial glance at human history shows today's world is vastly different from that of a century ago, which is almost unimaginably different from 50,000 years ago. And yet a Cro-Magnon baby, magically plunked down at birth in 21st century America, could very well find herself comfortably reading on her iPad, and offspring of today's technophiles could adapt to the world of saber-toothed cats and stone axes.
Consider that stone ax. The history of civilization is, in large part, one of ever-greater efficiency in killing, as in the progression from club, knife and spear, to bow and arrow, musket, rifle, cannon, battleship, bomber and nuclear-tipped ICBM. At the same time, the human being who creates and manipulates these devices has not changed much at all.
As a biological creature, in fact, Homo sapiens is poorly adapted for killing, given his puny nails, minimal jaws and laughable little teeth. But cultural evolution has made it not only possible but easy.
This biology-culture disconnect is especially acute in the realm of nuclear weapons. At the one-year anniversary of the bombing of Hiroshima, Albert Einstein famously noted that “the splitting of the atom has changed everything but our way of thinking; hence we drift toward unparalleled catastrophe.”
He might have been talking about musk oxen. These shaggy Arctic beasts have long employed a very effective strategy when confronted by their enemies: wolves. They herd the juveniles into the center while the adults face outward, arrayed like the spokes of a wheel. Even the hungriest wolf finds it intimidating to confront a wall of sharp horns and bony foreheads, backed by a thousand pounds of angry pot roast. For countless generations, their behavior served musk oxen well.
But in more modern times, their primary threat hasn't been wolves, but human hunters carrying high-powered rifles. Today, musk oxen would do better if they spread out and high-tailed it toward the horizon, but instead they respond as previous generations always have — forming their trusted defensive circle — and are easily slaughtered.
Human actions changed everything but the musk ox way of thinking; as they clung to their biology they drifted toward unparalleled catastrophe, until another human action (conservation) intervened.
Humans also cling to (or remain unconsciously influenced by) our biology. That stubbornness is especially evident when it comes to thinking, or not thinking, about nuclear weapons.
Take, for example, this widespread difficulty: When told something is “hot,” most of us readily think in terms of boiling water or burning wood. The biological creature within cannot effectively grasp the meaning of millions of degrees. Before the artificial splitting of uranium and plutonium atoms, nuclear explosions had never occurred on Earth. Even in the wake of Hiroshima and Nagasaki, we are unprepared to wrap our minds around them, including the vast scale of destruction, deaths by the millions, and in minutes.
And so the conflict between our biological natures and our cultural products cloaks nuclear weapons in a kind of psychological untouchability.
But does this mean that things are hopeless, that we are the helpless victims of this aspect of our human natures? As Carl Sagan emphasized, eliminating nuclear weapons — certainly not building more or upgrading what we have — is a basic requirement of species-wide sanity and good planetary hygiene.
The missiles, bombers, bombs and warheads in our nuclear arsenal are our own creation, our own responsibility, not something imposed upon us by a malignant God. And we are the most adaptable of all creatures, probably the only ones capable of acting, consciously, in our own self-interest. Once we stop acting like musk oxen.
David P. Barash is an evolutionary biologist and professor of psychology at the University of Washington.