Data from: From cryptic to colourful: evolutionary decoupling of larval and adult colour in butterflies
Data files
Dec 04, 2019 version files 154.72 MB
Abstract
Many animals undergo complete metamorphosis, where larval forms change abruptly in adulthood. Colour change during ontogeny is common, but there is little understanding of evolutionary patterns in these changes. Here we use data on larval and adult colour for 246 butterfly species (61% of all species in Australia) to test whether the evolution of colour is coupled between life stages. We show that adults are more variable in colour across species than caterpillars and that male adult colour has lower phylogenetic signal. These results suggest that sexual selection is driving colour diversity in male adult butterflies at a broad scale. Moreover, colour similarities between species at the larval stage do not predict colour similarities at the adult stage, indicating that colour evolution is decoupled between young and adult forms. Most species transition from cryptic coloration as caterpillars to conspicuous colouration as adults, but even species with conspicuous caterpillars change to different conspicuous colours as adults. The use of high-contrast coloration is correlated with body size in caterpillars but not adults. Taken together, our results suggest a change in the relative importance of different selective pressures at different life stages, resulting in the evolutionary decoupling of coloration through ontogeny.
Methods
We collected standarised RGB values from online photographs for 246 species of Australian butterflies and their caterpillars. The sRGB values presented were converted from raw aRGB values and an equation in an R function, which can be sent on request.
butter2_extractecNov11.csv -- dataset with all colours measured, for use in R code
butter2_extractecNov11.xls -- dataset but with metadata as tab
Also included: phylogenies used, file names to match data with phylogeny, R code and R functions employed.
Usage notes
Column headings for dataset:
species | species name, does not match phylogeny so file with names is needed to match |
fam | family |
code | code of individual measure |
colour | general colour measured |
percentage | area occupied by colour measured |
stage | life stage measured |
Ili_apo | aposematism code, not used in analyses but collected (3 highly conspicuous and probably aposematic) |
quality | quality of the photo , with 3 being the highest quality, analyses of high quality include only those with 3 |
size_cat | caterpillar size |
size_adult | adult size |
measure_code | code of measurement, all info combined |
fit1$cluster | values of colour cluster ID |
sR | standard R, raw value measured from photo, converted from aRGB |
sG | standard G, raw value measured from photo, converted from aRGB |
sB | standard B, raw value measured from photo, converted from aRGB |
R_c | R value of cluster the colour was assigned to, all analyses done with this RGB coordinates |
G_c | G value of cluster the colour was assigned to, all analyses done with this RGB coordinates |
B_c | B value of cluster the colour was assigned to, all analyses done with this RGB coordinates |