6 ideas
Domestication can be read as a coevolutionary bargain in which plants exploit humans as much as humans exploit plants. By gratifying specific human desires, species like the apple and potato recruited people to propagate them across continents, turning the farmer into something like the bee that serves the flower.
John Chapman planted apples from seed along the American frontier. Because apples don't breed true from seed, this produced huge genetic diversity, and most of the fruit was sour and fit mainly for hard cider. This seed-grown profusion let the apple adapt to American conditions and yielded new varieties, before grafted monocultures later narrowed the gene pool.
In 1630s Holland, the most prized tulips had flamed, 'broken' petals that were in fact caused by a virus that also weakened the bulbs. Speculation in these rare, unpredictable beauties drove bulb prices to extreme levels before the market collapsed. Beauty, scarcity, and the impossibility of reliably reproducing a trait fed a speculative frenzy.
Flowers evolved beauty to attract pollinators, and some species then found in humans an even more powerful pollinator. The human attraction to symmetry, color, and novelty in flowers made ornamental plants worth cultivating even though they offer no nutritional value.
The American drug war pushed cannabis growing indoors, and growers there bred compact, high-THC hybrids using lights and cloning. Pollan argues that the pressure of prohibition, by selecting for plants that were small and easy to hide yet highly potent, made the plant stronger.
The genetically uniform potato let Ireland feed a growing population cheaply until blight destroyed the crop and caused the Great Famine. Modern engineered potatoes such as Bt NewLeaf extend the same pursuit of control, replacing biological diversity with uniformity and chemical or genetic inputs. That concentrates risk in a single point of failure.