Free The Triumph of Seeds by Thor Hanson Page B

grain field is the annual mustard called rape, whose tiny seeds produce copious quantities of canola oil. (Like “coconut water,” the name “canola” is a savvy branding invention. No one, presumably, felt very optimistic about marketing aproduct called “rape oil.”)
    “There is one general rule,” he finally admitted. “Oil and fat-storing seeds have the most energy per weight. You get more punch from lipids than from a big pile of starch.” He also told me that seeds don’t usually access that energy until after germination. Most species keep enough sugars on hand to spark the embryo to life, and then start the more complex process of accessing their stored reserves. Starches convert to sugars relatively easily, but it takes a whole series of events to change protein, fat, or oil into a form useful for cell activity. Our own bodies work the same way, which is why you see competitors in Ironman triathlons downing bananas, cereal bars, or even jam sandwiches rather than slabs of bacon or cups of olive oil. In terms of seed evolution, this puts the emphasis on thenewly sprouted plant and the resources its growing conditions will demand. But while that may explain why forest seeds like cacao and almond use fats and oils to fuel slow, steady growth in the shade, it does nothing to explain why mustard seeds in wide-open fields use the very same things to grow quickly. “There are exceptions,” Bewley said. We were talking on the phone, but I could almost see him shaking his head. “There are always exceptions.”
    The British physicist William Lawrence Bragg once said that science is less about obtaining new facts than “discovering new ways of thinking about them.” Talking to Derek Bewley didn’t settle my questions about seed energetics with new information. Instead, it did so by reminding me of an important and fundamental truth about evolution itself. Charles Darwin once wrote, “Man may be excused for feeling some pride at having risen . . . to the summit of the organic scale.” This statement was fitting to its time, an era when any respectable Victorian gentleman naturally placed respectable Victorian gentlemen on the top rung of the evolutionary ladder. The trouble lies in the whole notion of evolutionary ladders and summits, the idea of a directional process climbing toward some notion of perfection. Of course, Darwin had a much more nuanced understanding of evolution, but this concept took root in our collective intellect and was perpetuated in cartoons, popular accounts, and even serious works of scholarship. The mind returns to it unconsciously, despite being surrounded by direct evidence to the contrary. If evolution progresses toward singularity, then how do we explain diversity—the 20,000 different grasses, the 35,000 dung beetles, the profusion of ducks, rhododendrons, hermit crabs, gnats, and warblers? Why are the most ancient life forms on the planet, bacteria and archaea, more diverse and prolific than all other species combined? Given time, evolution is much more likely to provide us with a multitude of solutions than it is to give us one ideal form.
    My mistake lay in assuming that seeds had perfected the “best” methods for storing energy. I wanted to think that natural selection had eliminated the various possibilities until only one or at mostseveral strategies remained, each adapted to a particular environment (forest, field, desert, etc.). The reality is far more complicated and far more interesting, like evolution itself—an endless and elegant articulation of the possible. Just as seeds can pack their lunches in different places (cotyledons, endosperm, perisperm, and so on), so, too, can that energy take many forms. If they offered only starch, seeds would no doubt still be successful in nature and we would still depend on them as a staple food. But without oils, fats, waxes, proteins, and other fuels, the seed habit might have lacked the versatility to dominate so many