Figure 3 Multidimensional domain (morphospace) of simulated branching patterns (A) and simulated walks through three single-task fitness-landscapes (B-D). (A) Simplified version of the morphospace represented in Cartesian space (x, y, z) consisting of two subdomains of shape (isometric and anisometric branching). Each walk is "seeded" with the simplest shape in the isometric domain (i.e., a Y-shaped ancestral form) and represents a series of genetically and developmentally unfettered steps that obtain phenotypic maxima or optima (shown at right). (B) A walk through a reproductive-success landscape. (C) A walk through a light interception landscape. (D) A walk through a mechanical stability landscape (see Table 1).