Fig. 4
Correlations between the degree of polarization and beetles’ reflectivity. Larger values in the degree of polarization indicate a dominant effect of left-handed chiral structures. The visible reflectivity is independent of the presence of highly efficient chiral structures (a) while the residuals of NIR reflectivity (extracted from a NIR-VIS regression to account for the correlation) are 0 or higher in beetles that lack efficient left-handed chiral structures (b). This pattern remains even after removing the species with a bilayered mechanism (squares) from the analysis. Plots show the mean and standard deviation (error bars) of the studied optical properties per species. Trend lines were calculated based on the estimates of the PGLS models.
