Sparing Nature: The Conflict between Human Population Growth and Earth's Biodiversity

Preface

B Preface After finally ushering my last book into press in 2000, I soon felt another book formulating itself in my mind. I enjoyed writing The Riddled Chain, although the topic of its final chapter—the relevance of evolutionary research to contemporary environmental concerns—was not covered as fully as I would have liked. But there were so many good books on humans and the current extinction crisis that I thought such a project would not be worth my while. Then I discovered a “missing link,” albeit not of the kind paleoanthropologists usually like to find. This one was the gap in the literature regarding any connection between human population growth and biodiversity losses. The discovery came while I was teaching a course called Human Ecological Adaptations, covering the environmental context of our lineage over the past few million years. As we covered the past ten thousand years, which we refer to as the “present,” the course focused on two major trends: the explosive growth of the human population and the ongoing mass extinction of plants and animals. My first surprise was that a frightening number of my students were unaware of either trend, despite constant exposure to the varied media that explore them in depth. So perhaps one more book would help send out the message. Nevertheless, I’ve always taught that the two global trends are related. A number of my students wanted to research this relationship further for their term papers, and I used to instruct them that there was a wealth of literature on the topic. As it turned out, I was wrong. There are many books on the biodiversity crisis, but at best they touch on human population growth for a few paragraphs. Likewise, despite a wealth of literature on human demography , its relationship to the extinction of other life-forms has barely been mentioned. At first, the lack of literature led me to doubt the connection between the A i x 00-R2435-FM 11/5/02 1:51 PM Page ix paired trends, so I began reading more and researched a few ideas on my own. It became abundantly clear that the connection is real, albeit relatively unnoticed . Thus my goal was set: to fill the gap in the literature with an extended essay, synthesizing the best of modern research and explaining it with a style that could awaken students young and old. The subject was too important to leave untreated. The challenge was to tackle such a large and complex topic without getting the book mired in unreadable detail. In my last book I tried to overcome a similar problem through the use of anecdotes, analogies, and occasional light relief. For this new book the anecdotes would be easy, as I have been privileged to visit many parts of the world from which I could draw examples— including my own backyard. Yet as for light relief, some of my friends asked me how I could possibly find humor in the overpopulation quagmire and the biodiversity crisis. So in writing on such a serious topic, I recalled the comment of a student who took my Human Ecological Adaptations course, from which this book got its inspiration. She said, to my amusement, “This was the most depressing course I’ve ever enjoyed.” From that springboard I took in other books that take a lighter approach to the maladies of today: comic novelist Douglas Adams’s Last Chance to See, cartoonist Gary Larson’s There’s a Hair in My Dirt, and my favorite, The Lorax, by Theodor Geisel (a k a Dr. Seuss). Nevertheless, the two main messages of this book are quite serious: (1) There is a connection between human population growth and biodiversity loss that goes back over a million years, and that becomes particularly evident in the past ten thousand years. (2) The greatest and most effective conservation measure to save earth’s biodiversity is to halt the growth of the human population, and perhaps reduce our numbers. As I combed the academic research journals, I was amazed at the amount of supportive evidence; nearly two hundred scientific works are cited in this book, and that is just a sampling of what is out there. My apologies to those scholars who have done relevant work but did not get cited—the enormity of the topic meant I had to pick and choose research that kept to the focus of the book. One cannot be an expert in all realms of...