Figure 18-1. Hypothesized relationships of heliconiines based on Brown (1981), illustrating major adaptive zones for Heliconius. The cascade of life-history innovations set in motion by pollen feeding is indicated by arrows and is discussed in the text. Numbers on horizontal lines indicate number of species, followed by number of races in parentheses. Horizontal pupae on the line leading to Eueides and Neruda are hypothesized to originate after the origin of pupal mating in Heliconius (open triangle).