That's the name of the first chapter — "" This Book is Not a Tree. "" Because in poetics, as Margaret Atwood pointed out, "" we write our history on the skin of fish with the blood of bears. "" And with so much polymer, what we really need is technical nutrition, and to use something as elegant as a tree — imagine this design assignment: Design something that makes oxygen, sequesters carbon, fixes nitrogen, distills water, accrues solar energy as fuel, makes complex sugars and food, creates microclimates, changes colors with the seasons and self-replicates.