Sir, I can nothing say,
But that I am your most obedient servant.
—William Shakespeare,
All’s Well That Ends Well (c. 1605)
Charles Darwin traveled with the HMS Beagle for five years, devoted eight years to the anatomy of barnacles, and spent most of his adult life ruminating on the implications of natural selection. The famed naturalist-monk Gregor Mendel hand-pollinated 10,000 pea plants over the course of eight Moravian springtimes, before finally writing up his thoughts on inheritance. At Olduvai Gorge, two generations of the Leaky family sifted through sand and rock for decades to piece together a handful of critical fossils. Unraveling evolutionary mysteries is generally hard work, the stuff of long careers spent in careful thought and observation. But some stories are obvious, crystal clear from the very beginning. Anyone familiar with children, for example, understands the origin of punctuation. It started with the exclamation point.
Nothing comes more naturally to a toddler than emphatic, imperative verbs. In fact, any word can be transformed into a command with the right inflection—a gleeful, insistent shout accented from a seemingly bottomless quiver of exclamation points. Whatever nuances of speech and prose might be gained by the use of comma, period, or semicolon clearly developed later. The exclamation point is innate.
Our son, Noah, is a good example. He began his verbal career with many of the expected phrases, from “Move!” and “More!” to the always-popular “No!” But his early vocabulary also reflected a more unusual interest: Noah was obsessed with seeds. Neither Eliza nor I can remember exactly when this passion began; it just seemed that he had always loved them. Whether speckling the skin of a strawberry, scooped from inside a squash, or chewed up in the rose hips he plucked from roadside shrubs, any seed that Noah encountered was worthy of attention and comment. In fact, determining which things had seeds, and which didn’t, became one of the first ways he learned to order his world. Pinecone? Seeds. Tomato? Seeds. Apple, avocado, sesame bagel? All with seeds. Raccoon? No seeds.
With such conversations a regular occurrence in our household, it’s no wonder that seeds were on my short list when it was time to settle on a new book idea. What might have tipped the balance was Noah’s pronunciation, which added a certain imperative to his botanical observations. Sibilance did not come easily to his young tongue, but instead of lisping he chose to replace ‘s’ sounds with a hard ‘h.’ The result was a barrage of double commands—every time he disassembled some unsuspecting piece of fruit he would raise the seeds in my direction and shout, “HEED!” Day after day, this scene repeated itself until I eventually got the message: I heeded the seeds. After all, little Noah had already pretty much taken over the rest of our lives. Why not put him in charge of career decisions, too?
Fortunately, he assigned me a topic dear to my heart, a book that I’d wanted to write for years. As a doctoral student, my research included studies of seed dispersal and seed predation in huge tropical rainforest trees. I learned how vital those seeds were, not just to the trees but to the bats and monkeys that dispersed them; the parrots, rodents, and peccaries that ate them; the jaguars that hunted the peccaries; and so on. Researching seeds enriched my understanding of biology, but it also taught me how their influence reaches far beyond the edge of forest or field; seeds are vital everywhere. They transcend that imaginary boundary we erect between the natural world and the human world, appearing so regularly in our daily lives, in so many forms, that we hardly recognize how utterly dependent we are upon them. Telling their story reminds us of our fundamental connections to nature—to plants, animals, soil, seasons, and the process of evolution itself. And in an age where, for the first time, more than half the human population lives in cities, reaffirming those links has never been more important.
Before this tale travels even another paragraph, however, I need to insert two caveats. The first is an important clarification that will preserve good relations with my many friends in marine biology. In the 1962 film Mutiny on the Bounty, there is a memorable scene where the rebellious sailors set Captain Bligh adrift in a longboat and then immediately toss every one of his hated breadfruit seedlings overboard. (Bligh had been giving the plants regular doses of fresh water even after the crew’s rations ran low.) As the little trees go over the side of the ship, the camera pans back to show them trailing in the Bounty’s wake: a handful of pitiful green motes on a vast, calm sea. Their prospects look dim, making an important point about the limitations of the seed strategy. While seed plants may triumph on dry land, different rules apply to the nearly three-quarters of the planet covered by oceans. There, algae and tiny phytoplankton hold sway, limiting their seed-bearing cousins to a few shallow-water varieties, the occasional bobbing coconut, and things cast off by sailors. Seeds evolved on terra firma, where their many remarkable traits have shaped the course of natural and human history. But it’s good to keep in mind that on the open ocean, they’re still a novelty act.
The second caveat acknowledges an area of seed controversy that lies beyond the scope and aim of this book. In graduate school, my curriculum included a one-credit seminar intended to familiarize students with the equipment used in a genetics laboratory. We met in the evenings once a week, donned white lab coats, and spent a couple of hours practicing with various tubes and pipes and whirring, beeping machines. As a simple exercise, the instructor showed us how to splice our own DNA into that of a bacterial cell. As the bacterial colony then divided and grew, our DNA would be copied ad infinitum, a basic form of cloning. Though of course we only used a tiny fragment of DNA and the results were crude, I distinctly remember thinking, “I shouldn’t be able to clone myself in a one-credit class.”
The advent of relatively straightforward techniques for genetic manipulation has ushered in a new era for plants and their seeds. Familiar crops, from corn and soybeans to lettuce and tomatoes, have been experimentally altered with genes borrowed from arctic fish (for frost resistance), soil bacteria (to make their own pesticide), and even Homo sapiens (to produce human insulin). Seeds can now be patented as intellectual property, and designed to include terminator genes that prevent the ancient practice of saving seed for future plantings. Genetic modification is a pivotal new technology, but it will be addressed only briefly in these pages. Instead, this book explores why we care so much in the first place. When modern genetics has also given us featherless chickens, glow-in-the-dark cats, and goats that produce spider silk, why is it that seeds are the focal point of the debate? Why do polls consistently find people more comfortable with the idea of changing their own genome, or the genomes of their children (for medical purposes), than they are with the notion of altering the genes in seeds?
The answers to these questions lie in a story that stretches back millions of years, wonderfully entwining the history of seeds with the history of our own species and culture. The challenge for me in writing this book lay not in filling it, but in deciding what material to include and what must be left by the side of the road. (For additional anecdotes and information, be sure to read the notes for each chapter. They are the only place in the book, for example, where you will hear about gomphotheres, slippery water, or the piper’s maggot.) Along the way we will meet fascinating plants and animals as well as many people who have made seeds a part of their own stories, from scientists and farmers to gardeners, merchants, explorers, and chefs. If I have done my job right, you will see in the end what I have come to know, and what Noah apparently realized from the start: seeds are a marvel, worthy of our study, praise, wonder, and any number of exclamations points. (!)