The Botany of Desire: A Plant's-Eye View of the World

by Michael Pollan

Either way, sweetness has proved to be a force in evolution. By encasing their seeds in sugary and nutritious flesh, fruiting plants such as the apple hit on an ingenious way of exploiting the mammalian sweet tooth: in exchange for fructose, the animals provide the seeds with transportation, allowing the plant to expand its range. As parties to this grand coevolutionary bargain, animals with the strongest predilection for sweetness and plants offering the biggest, sweetest fruits prospered together and multiplied, evolving into the species we see, and are, today. As a precaution, the plants took certain steps to protect their seeds from the avidity of their partners: they held off on developing sweetness and color until the seeds had matured completely (before then fruits tend to be inconspicuously green and unpalatable), and in some cases (like the apple’s), the plants developed poisons in their seeds to ensure that only the sweet flesh is consumed.