Fig. 1.

Diversity and evolution of hair-pencils on the wings of Bicyclus butterflies. (A) Artificially colored scanning electron micrograph of the hindwing, yellow hair-pencil (hair-pencil 1) in Bicyclus anynana. The boxed area (base of the hair-pencil scales) is expanded to the right to illustrate the elongated and densely packed nature of the hair-likes scales that make up a hair-pencil. (B) The different combinations of hindwing and forewing hair-pencils in male Bicyclus butterflies. The number of hair-pencils and the name of the species are denoted at the bottom left. Colored circles indicate the position of the base of each hair-pencil corresponding to the schematic in C. (C) Evolutionary history of hair-pencils at homologous positions on the wing within the Bicyclus lineage. Locations, number, and color codes of the different traits are given in the schematic and their presence/absence in each species is listed to the right. Filled rectangles on the phylogenetic tree indicate the likely gains of the traits for which either a single- or a multiple-origin scenario at the MRCA of all the species bearing that trait was significantly supported. Arrows indicate the two likely gains for hair-pencil 2 and stars indicate the six likely gains for hair-pencil 4 within Bicyclus. For traits where a single- or multiple-origins scenario was equally supported, a single-origin was mapped (black arrowhead).