Wrangham cites several studies indicating that in fact humans don't do well on raw food: they can't maintain their body weight, and half of the women on a raw-food regimen stop menstruating. Devotees of raw food rely heavily on juicers and blenders, because otherwise they would have to spend as much time chewing as the chimps do. It is difficult, if not impossible, to extract sufficient energy from unprocessed plant matter to power a body with such a big, hungry brain.

We used to eat economically. One of the things that happened is that we lost the cultural skills that used to allow people to eat well cheaply. For example making three or four meals from a chicken, rather than buying chicken breasts.

In a way, the more techniques you apply, the less important the ingredients are. It shouldn't be that way, but you can get away with it. But if you're highlighting this astounding artichoke, it's got to be an astounding artichoke.

In Joel's view, that reformation begins with people going o the trouble and expense of buying directly from farmers they know - "relationship marketing," as he calls it. He believes the only meaningful guarantee of integrity is when buyers and sellers can look one another in the eye, something few of us ever take the trouble to do. "Don't you find it odd that people will put more work into choosing their mechanic or house contractor than they will into choosing the person who grows their food?"

Ecology also teaches that all life on earth can be viewed as a competition among species for the solar energy captured by green plants and stored in the form of complex carbon molecules. A food chain is a system for passing those calories on to species that lack the pant's unique ability to synthesize them from sunlight.

Eat all the junk food you want as long as you cook it yourself.

When chickens get to live like chickens, they'll taste like chickens, too.