magine a North America without bison, an Australia without koalas, an Africa without zebras or lions or gorillas. This impoverished world is eerily empty, silent. We are saddened to be so alone with ourselves.
At the beginning of Twilight of the Mammoths, paleoecologist Paul Martin asks us to do just that. "The missing animals simply do not exist," he writes. "We know them only from fossils." Martin wants us to feel his pain. He is a man acutely aware that in the past 50,000 years of "near time," over half the world's species of mammals weighing more than 100 pounds went extinct. Specifically, North America lost two-thirds of its megafauna and South America three-fourths. For Martin, the wild America we know today is nothing but a shadow. Where are the lions and camels, the 10,000-pound ground sloths, the mammoths and glyptodonts? This scientist is not ashamed to mourn openly: "I view the loss as horrendous. Without the large mammals, the land is tame; much of the emotion of the out of doors is drained."
More than 40 years ago, Martin proposed that these extinctions were caused not by climate change -- the prevailing theory -- but by human hunting. Twilight of the Mammoths is his opus, a patient and detailed defense of the overkill theory as well as the portrait of a scientific career and the arc of a scientific debate. Martin takes his readers from his graduate-school days looking through a microscope at fossil pollen to the heady experience of standing in Rampart Cave at the western end of the Grand Canyon, "chest deep in layers of stratified sloth dung." Pack-rat middens would yield fossil bones of the extinct Shasta ground sloth, an extinct goat, an extinct horse the size of a burro, and the nearly extinct California condor. The deposits had lost any trace of decay, and the air smelled resinous, "like incense." Martin felt the hairs rise on the back of his neck: "One did not need to be a Sufi or mystic to sense that this dimly lit, low-ceilinged chamber was a sacred sanctuary. More than a sepulcher for the dead, Rampart Cave venerated the extinct."
Later, at a place in Utah called Bechan Cave (from the Navajo word for "big feces"), Martin would sort through the dung of Columbian mammoths. Again, in "a huge dry rock shelter like a cathedral," he felt blessed. He was reaching back into our "deep history" to an untamed land of extraordinary richness. It was another sacred site.
The book's unabashed sense of wonder makes it more engaging than the usual science writing. But for Martin, a good hypothesis still has to be testable, and theories are meant to be challenged, not sanctified. This is a story about science, not Sufi mysticism, punctuated with the enthusiasm of a man whose work and pleasure are the same -- a man in love with the Pleistocene, a world of giant scale, unimaginably vital and irretrievably lost.
Or maybe not. Martin's concluding chapters promote the introduction into North America of species similar to the ones that went extinct during the Pleistocene. His ideas are controversial, to say the least. In the working world of environmentalists, where politics can be more vicious than a giant short-faced bear, they may seem like a distraction. In my home state of New Mexico, we have not yet successfully reintroduced the native otter, much less the Mexican wolf. And Martin wants elephants and cheetahs?
Still, his perspective has an emotional resonance. He wants us to remember a time when "we were both hunters and the hunted," when we followed the tracks of large animals and learned from them where to find water, food, and shelter. We were surrounded then, outnumbered, by "otherness." We lived in fear and wonder, dependent on nature, in awe, in touch, in our natural setting.
No matter what caused the great beasts to disappear, Martin's wish is for us to reclaim our heritage. He hopes that someday "six-year-olds who can rattle off fifteen generic names of dinosaurs will start mastering such strange names as Castoroides for the giant beaver in the Midwest." Twilight of the Mammoths is an intimate glimpse into one man's passion, as well as a bit of time-traveling, a grand tour of a truly wild America, and a compelling example of how scientists explore and test their ideas.
-- Sharman Apt Russell