What the salad tried to do to us. The first ambition of any plant is to make itself uneatable. Long before anything clever walked on earth, plants settled on poisoning anything with a mouth. If you can’t run, you better taste terrible. The only way to stay alive was to face your predator (dinosaur, beetle, goat, man) with chemistry. Plants got clever in the only way available to them. They made toxins, astringents, enzymes, fibrous defences. Which made them and their parts bitter. Also indigestible, and outright poisonous. In evolutionary terms, it was a cunning move. Not that the plant knows anything about cunning. But the natural consequence was deterrence. You bite, you suffer. You learn. You stop biting. Humans responded in the human way. By using fire and other things. We boiled, we burned, we soaked, we crushed, we fermented. We pickled. We found ways to take the bitter poisonous offerings of plants to our hungers. We hacked our own biochem, made over 50 types of CYP450 enzymes. They’re fascinating. A plant toxin molecule (alkaloid, glucosinolate, cyanogenic glycoside, saponin etc) is like a greasy stain. CYP450s act like detergent: They grab it, break it apart, make it dissolve in water, and wash it away. Cats don’t have a lot of this stuff. The thiosulfates in a couple of cloves of garlic can trigger a dangerous oxidative crisis in cat blood. About four cloves (of garlic) can be a potentially lethal dose. A tiny amount of solanine from a raw potato can sicken and kill a rabbit. Without a particular kind of P450, a potato would be your last meal. We figured out how to eat the enemy. And then we got kinky about it. Our tongues learned to relish the sting. And the rot. We started liking the burn and the bitterness. We started having poison for the plot. Hot sauce. Tannins. Coffee so strong it peels paint. Flavour is a toxin we’ve come to applaud. Plants spent a hundred million years trying to kill us. We’ve spent a hundred million years learning to savour their attempts. That’s the story, give or take a few famines and a few million deaths.