"We used to eat a greater diversity of plants and animals," Pollan said. "But over time, as we've industrialized agriculture, a process that really begins around World War II, after World War II, we start narrowing the number of crops we're growing. We kind of focus in on a couple of big ones. Corn and soybeans, two of the biggest, and turning corn and soy into the appearance of diversity we find in the supermarket. And all those different things, you know, they look really different. If you, if you go down the middle aisles in the supermarket, you see so many different brands and so many different products, but most of them are processed corn and soy. So we're eating those two species and we used to eat dozens more species."