Trait dependent diversification analyses
To test whether Preponini lineage diversification has been dependent on
phenotypic evolution (i.e. color pattern), we used the Equal-Splits with
Simulated null model (ES-sim) method
(Harvey and Rabosky, 2018). ES-sim
employs a tip and rate correlation technique to test for the
significance of the correlation between trait values at the tips and the
phylogeny’s branching pattern in the absence of an evolutionary model.
Harvey and Rabosky (2018) showed
that for phylogenies with ~50 species, ES-sim performed
better in the Type I error rate and had comparable power to QuaSSE
(Quantitative State Speciation and
Extinction, FitzJohn, 2010), a method commonly used to jointly model
diversification and the change in continuous traits. In addition, ES-sim
is useful for small phylogenies with few and slight changes in
diversification rate, which might be the case in our study
(Harvey and Rabosky, 2018). As a
result of the ES-sim test, we obtained i) a Pearson’s correlation
coefficient (rho), which quantifies the strength of the relationship
between traits and each lineage’s diversification rate and ii) the
simulation-based two tailed probability value (p-value) which allows
comparison of the data to a null hypothesis.