Via Willam Zinsser’s On Writing Well (a real gem):
Economy and survival are the two key words in nature. Examined out of context, the neck of the giraffe seems uneconomically long, but it is economical in view of the fact that most of the giraffe’s food is high in the tree. Beauty as we understand it, and as we admire it in nature, is never arbitrary.
Moshe Safdie, Beyond Habitat