continent swarms with creatures, many of them overtly large, many of them horned and hooved, some of them headed toward oblivion: giant bears, dire wolves, saber-toothed cats; an American cheetah, a shrub ox, a species called yesterday's camel; mountain goats that eat the bark of Douglas firs, giant sloths foraging near the Grand Canyon.
Behind retreating ice, a wave of Siberian Homos spreads southward, jabbing Pleistocene megafauna with their little spears, dragging bloody mammoth haunches off to shelters of rock and laying them at the feet of their enamorada.
For 99 percent of our existence as humans, we lived as nomadic hunters and foragers. That leaves barely a blip for sedentary agriculture, written language, armies, and serious biological amnesia. Yet a river of creatures lives inside our cranium—reptiles in our brain stem, ocean life in our olfactory nerves, the whole of primate evolution in our sexuality, boldness, and self-awareness.
Paul Shepard calls the Pleistocene “the era of our becoming,” a formative period for slow-breeding, bipedal, hunting omnivores. He uses this Cenozoic moment to underscore a central tenet of his work: The structure of the human brain, the very evolution of intelligence, depends on animals.
Although some of his arguments have been shown to be flawed, Shepard's words illuminate the context, if not the biology. “Animals are among the first inhabitants of the mind's eye,” he wrote in Thinking Animals. “They are basic to the developmentof speech and thought. Because of their part in the growth of consciousness, they are inseparable from a series of events in each human life, indispensable to our becoming human in the fullest sense.”
In the daydream, I am looking through the wrong end of the binoculars. I see the pale retreating rumps of the Blue Door Band. They are the size of dissolving pollen grains. What if you scan the land for these wild sheep, and for the other descendants of the ice mammals, but find none? What happens when, as the experts tell us, at the end of the current millennium most of the plant, animal, and bird species we know today are gone? Will this leave us brain-damaged?
In between sheep visits, I was under the impression that my life was every bit as ordinary as other people's lives, typical lives, with a Mercedes in one's field, Zen-trained coyotes in the river bottom, and ice-age mammals in the canyons, eating cactus.
Part of my life was the typical middle-aged gut-churning panic of riding a globe through space, a globe that spins through time with utter indifference to one's being. All over America, millions of fellow baby boomers were standing in front of the mirror in their jammies, utterly astonished to discover that dissipation and disintegration—of mind, of body, of matter—are essential elements of existence, and that the slide toward them is ever quickening and inevitable.
Watching wild animals intensely, like prayer, somewhat tempered the panic. At home, however, I paid far too much attention to my own cerebral senescence. I noticed peculiar episodes in brain activity.
It began one day in the post office. I stood at the counter, wearing an old teal-colored Eddie Bean barn coat over my jammies, a letter in hand. Suddenly, a meteor struck my head and erased 40 percent of my vocabulary. The D words slid downthe Formica counter and headed toward the stamp drawer. The B's formed snowdrifts against the postmaster's government-issue steel gray desk. My numb tongue flung participles at the most wanted posters. Nouns fled in great chunks.
For three panicked minutes, eyes wide in horror, I was unable to pluck the word certified from the cosmos. The postmaster politely rumbled a barrage of questions at me: “Stamps? Parcel post? Delivery confirmation?” Speechwise, the tip of a peninsula broke off from my mainland brain and the sea flooded into the breach behind it.
In the days that followed, a kind of sonic language began to spill all over my