Phylogenetic contrasts:
Only species with at least one measure from each caste on Antweb.org
were used in analysis; species of the same species complex were
substituted if the species in the phylogeny was not fully represented in
Antweb.org; species complex information was obtained from species
information in Antwiki.org. The worker ratio was the largest divided by
the smallest worker head width, while the sexual ratio was the mean gyne
head width divided by the mean male head width. The gyne:worker ratio
was calculated as the average gyne size divided by the minimum worker
size.
Genus-level phylogenies (Pheidole: (Moreau 2008), Pogonomyrmex: (Johnson
and Moreau 2016)) were used to address non-independence of species.
Relationships of size variation between castes were tested using a
linear model with phylogenetic correction. Phylogenetic correction was
done using independent contrasts as calculated using the crunch function
in the caper package in R (Orme et al. 2018).