Trees

Trees serve as the primary biological model for growth plate concepts in this chapter. Their growth occurs exclusively at apical meristems (shoot tips) and root tips - not throughout the organism. This concentrated growth pattern explains why tree rings work: each ring represents growth added to the outside, not distributed throughout.

Trees also demonstrate apical dominance through auxin hormone production. The tip of the main shoot chemically suppresses lateral bud growth, directing resources preferentially to vertical growth. This ensures the tree reaches sunlight rather than spreading resources evenly and being overshadowed by taller neighbors.

The tree model provides the conceptual foundation for Amazon's sequential category expansion and the chapter's core insight that growth must be concentrated, not diffuse.