Fig. 1
Optical properties mapped onto the consensus tree for the studied beetles. Colored squares (heat map) represent the analyzed optical properties, corresponding to the diagrams in the inset (lower-right). Calibrated photographs of select species illustrate the diversity observed. We analyzed reflectivity in visible (VIS), near-infrared (NIR residuals – see rationale in supplementary figure S2) and their sum (TOT). We considered two polarization traits (see rationale in supplementary figure S3): degree of polarization (POL), and the negative of the relative reflectance in right-handed polarization as a proxy for the presence of pigments (-RCP). Species marked with circles in the NIR column have high NIR reflections due to a unique bi-layer68. The NIR mechanisms in the other species of this group have not been investigated. The tree is a MCC consensus used for illustration (See Supplementary Figure S4 for information on node support and topological constraints involved in the full set of sample trees used for comparative analysis).
