Co-evolution is what has shaped modern agriculture, the mass cultivation of plants, animals, and fungus for human sustenance. Our domineering and self-important collective human psyche often puts us as the final arbiters, the Gods of the Garden, beholden only to our own whims. This book attempts to flip this paradigm on its head. We are not the Gods that possess complete domination over life, at least not yet. Nature ultimately is in control (though not an intentioned or conscious control), just as animals and plants in the wild are waging evolutionary warfare on each other - selecting for resistances to chemicals, building exoskeletons against predators, increasing running muscles in carnivorous predators, increasing eye-sight capabilities to see predators, continue ad infinitum - humans are in an unwitting war of desire on the plants we cultivate. We unconsciously and consciously select plants we find useful or desirable while the plants evolve the traits we want because the plants which cater to our needs are more successful, thus their genes are further propagated. The "Gods of the Garden" phrase gives way to the more accurate "Unwittingly Cooperative Caretakers of Plants" or perhaps something equally as awkward and verbose. Throughout the book, Pollan continually connects the assumed messianic paradigm with Greek polytheism, where Gods represented different facets of life. In a simple dichotomy, Pollan separates plants to appeal to Apollonian order or Dionysian frivolity.
Apples were introduced into North America by European colonists and part of what has made them so successful is their adaptability. Apples are examples of extreme "heterozygotes", rather than expressing the the DNA of their parents in a straightforward manner (with slight mutations), apples exhibit significantly different characteristics than their progenitors. Agriculturally, apples are grown exclusively through asexual grafting with sexual seed reproduction occurring only in wild apple trees. Currently, there are still a wide variety of cultivated apple breeds and this is due precisely to their extreme genetic variability. There are 7,500 different apple cultivars with around 25 varieties grown in commercial agriculture. Apple trees grown in a cloned orchard are more prone to disease than wild varieties due to their reduced genetic fitness. Therefore, the work of staving off harmful fungus and other such maladies falls to us, the caretakers of our genetic creations. According to Pollan, our agricultural domestication of apples has gone too far. Reduced to a few handfuls of commercially cultivated cloned varieties, the natural genetic fitness of apples has been compromised. While our genetic clones are stuck in an evolutionary limbo--pests, fungus, bacteria, and insects are forever evolving and eventually, with the right combination of genes, they're going to win.
The tulip represents the ultimate quintessential flower. Simplicity, color, and beauty with an abstractness of emotions. Tulips are for kids, states Pollan, they are simple to draw and visually uncomplicated. They are the least Dionysian of flowers, their form being extremely ordered and perhaps their visual simplicity doesn't lead to overt passionate emotions. The "tulipomania" in Holland during the 1600s was a savage uprooting of the tulip's unemotional nature, people were willing to sell their homes for the mere promissory note of future tulips. As the market spiraled out of control, with tulips being sold for obscene prices, the most sought after prize was the "break"--tulips that had a streak of contrasting, passionate color across their uniformed simplicity. These broken tulips were rare and for unknown reasons at the time, created less progeny. In the 1920s, scientists discovered that broken tulips were caused by a virus which actually weakened the vitality of the plant. This throws natural selection against a brick wall, as humans were artificially selecting for a visual trait which actually made the plant sickly and diseased. From the point of view of the tulip, the human relationship was detrimental, but from the point of view of the aphids that spread the virus, this was pure evolutionary genius.
Marijuana represents the pure Dionysian plant. Visually ugly but contained within its flowers are powerful intoxicants. Human cultivators have morphed this highly adaptable weed into plants of pure delight, eliciting ever higher concentrations of THC content. With modern techniques, the marijuana plant can be forced to overproduce and does so quite willingly. Pollan describes his own misadventures with growing marijuana in his garden, from germinated seed to the eventual paranoid and frantic uprooting of his plants. Pollan then attempts to place an intoxicating plant in terms of evolution. How did THC first manifest? Pollan lays out his best theories (although since he is not an evolutionary botanist, his hypothesis seems perhaps half-baked) and tries to place the reasons for humans seeking out intoxication within an evolutionary context. Drugs can induce feelings of "transcendence" and Pollan begins to speculate (with some scientific backing) about the purpose of memory loss and normal functioning. Our brains are sensory input machines that are under constant assault from the outside and without a memory loss function, we would be quickly overwhelmed with our sensory memories. THC has been shown to effect short term memory quite substantially and endocannabinoids are produced naturally by the body which activate cannabinoid receptors in the brain. As far as what exactly that means, scientists are still unsure but cannabinoid receptors are similar in function to monoamine neurotransmitters (such as acetylcholine and dopamine) but vary in some respects.
The potato is, even more than the apple, proof of our strong influence over the evolution of plants. Wild potatoes are toxic, inedible, and without our evolutionary influence we would not be eating them. In the case of some potatoes, this control combined with modern technology enables us to force whatever evolutionary design we see fit in almost unimaginable ways. Pollan writes about his personal experiences with NewLeaf genetically modified potatoes by Monsanto. Engineered to be resistant to the Colorado beetle, Pollan's NewLeafs grew with fervor. He marveled at their perfection, their supreme triumph over nature. Removed from the market due to pressure from the anti-GMO lobby (mostly against McDonald's, one of the largest buyers of potatoes in the United States), Pollan expressed irrational fear against eating his modified potatoes. He left them sitting on his porch in a plastic bag, unable to be sliced for a conscious-free potato salad.
To provide my final thoughts, overall I felt like while being an entertaining read, this book is not a science book and it undoubtedly isn't intended to be. Though Pollan shows an understanding of evolution, he does a fair bit of simplification and speculation. I appreciate Pollan's ability to not blindly pander to the naturalistic fallacy. When he is critical of agricultural pesticides and GMOs he's not doing it in an unintelligent way--he provides evidence and counterpoints to his ideas. He seems like what a journalist should be, somehow in the middle of two opposing ideas: modern technological agriculture and pure organic agriculture, himself wrestling between the two (though he obviously leans towards pure organic). Our ideas of agriculture run between two diametrically opposed schools of thought. In my opinion, this is a false dichotomy. The way to solve our agricultural crisis lies somewhere in the middle of the two. I like to think that Pollan agrees with me.
