Tim Flannery’s book will forever change your perspective on the North American continent. The Eternal Frontier is history, but on a scale unimagined by most historians, for it begins with the scorching of our continent 65 million years ago and ends in the future. Flannery guides us on a sweeping odyssey through time, in which he synthesizes vast amounts of information from geology, paleontology, and human history. Crisis and recovery are the leitmotifs, as continents separate and collide with profound consequences for the earth’s climate and its living things.
Flannery is a distinguished paleontologist, accomplished writer, and director of the South Australian Museum. Why, one might ask, is an Australian writing about the history of North America? As a student of the evolution of mammals and the environments in which they lived, Flannery unavoidably took an interest in North America. Thanks to abundant fossil deposits well distributed over time, the history of mammals is writ more clearly on our continent than anywhere else. North America gave rise to some globally successful lineages—horses, camels, dogs—and served as a proving ground for numerous others as they migrated in and out over intermittent land bridges to other landmasses. But The Eternal Frontier is far more than a bestiary of extinct mammals. Half the book is a penetrating, introspective account of the role we humans are playing on the evolutionary stage. As an outsider, he sees us North Americans without blinders, and takes us to task for our foibles with a candor that will surely make some readers squirm.
The history of life on earth is largely driven by events of a kind scientists call nonlinearities, radical breaks from the status quo. Among them are continental mergers and breakups, drastic changes in climate, the opening and closing of corridors of intercontinental (or interoceanic) migration, and, of course, extinctions of species. Over one lifetime, such events are so rare as to escape the power of natural selection. No creature adapts to something that has never happened before. Thus the all-too-human response to the prospect of nonlinearities is denial. We do it as individuals when we smoke cigarettes or build expensive houses on Atlantic barrier islands, and we do it as a matter of public policy in connection with global climate change and the use of natural resources. One cannot come away from this book without being deeply unsettled by the repeated failures of our species to heed the warnings of impending non-linearities.
The story opens with one of the most extraordinary nonlinearities in the earth’s history, the moment when an asteroid the size of Manhattan sliced into the underbelly of North America at a speed of 15 miles a second, gouging a trough in the earth’s crust so broad that from one rim it would have been impossible for someone to see the other. The heat generated by the impact is estimated to have been a thousand times that received from the sun, enough to fry the continent. The …