DOI: 10.5061/dryad.1740n0h
title: Data from: Sexual dichromatism drives diversification within a major radiation of African amphibians

description: Theory predicts that sexually dimorphic traits under strong sexual
 selection, particularly those involved with intersexual signaling, can
 accelerate speciation and produce bursts of diversification. Sexual
 dichromatism (sexual dimorphism in color) is widely used as a proxy for
 sexual selection and is associated with rapid diversification in several
 animal groups, yet studies using phylogenetic comparative methods to
 explicitly test for an association between sexual dichromatism and
 diversification have produced conflicting results. Sexual dichromatism is
 rare in frogs, but it is both striking and prevalent in African reed
 frogs, a major component of the diverse frog radiation termed
 Afrobatrachia. In contrast to most other vertebrates, reed frogs display
 female-biased dichromatism in which females undergo color transformation,
 often resulting in more ornate coloration in females than in males. We
 produce a robust phylogeny of Afrobatrachia to investigate the
 evolutionary origins of sexual dichromatism in this radiation and examine
 whether the presence of dichromatism is associated with increased rates of
 net diversification. We find that sexual dichromatism evolved once within
 hyperoliids and was followed by numerous independent reversals to
 monochromatism. We detect significant diversification rate heterogeneity
 in Afrobatrachia and find that sexually dichromatic lineages have double
 the average net diversification rate of monochromatic lineages. By
 conducting trait simulations on our empirical phylogeny, we demonstrate
 our inference of trait-dependent diversification is robust. Although
 sexual dichromatism in hyperoliid frogs is linked to their rapid
 diversification and supports macroevolutionary predictions of speciation
 by sexual selection, the function of dichromatism in reed frogs remains
 unclear. We propose that reed frogs are a compelling system for studying
 the roles of natural and sexual selection on the evolution of sexual
 dichromatism across both micro- and macroevolutionary timescales.
description: Supplemental Figure
 1Figure S1. A species
 tree of Hyperoliidae inferred from 1,047 gene trees with ASTRAL-III. Node
 support is shown for quartet support values and multi-locus bootstraps,
 with branch lengths depicted in coalescent units (except for tree tips,
 represented by dotted lines).FigS1_SpeciesTree_SeqCap.pdfSupplemental Figure 2Figure S2. A chronogram of Afrobatrachia inferred from the multilocus BEAST analysis of 283 species. Taxa labeled with blue color denote the 153 species included in the hyperoliid species tree that was used as a partial constraint tree in this analysis. Node support values are not shown because the tree topology was fixed, but error bars representing the 95% HPD for dating estimates are provided.FigS2_Afrobatrachia_Divergence_Dating.pdfSupplemental Figure 3Figure S3. A comparison of Bayesian ancestral character reconstructions inferred using the stochastic Mk model of character evolution with symmetrical (Mk1) or asymmetrical (Mk2) transition rates in combination with a strict clock or random local clock model. All analyses enforced a monochromatic root prior. The marginal likelihoods and average number of state changes are shown for each analysis. Node sizes reflect the posterior probability for the inferred character state, and tips and nodes are colored with monochromatism in yellow and dichromatism in blue.FigS3_Reconstruction_Comparisons.pdfSupplemental Figure 4Figure S4. An illustration of transitions to secondary monochromatism inferred using Bayesian ancestral character reconstruction with the Mk2 and strict clock models. Large nodes outlined with red represent inferred transitions to monochromatism from a dichromatic ancestor. States at nodes and tips are colored with monochromatism in yellow and dichromatism in blue.FigS4_SC_mk2_Reversals.pdfSupplemental Figure 5Figure S5. Ancestral state reconstruction of the observed and hidden state combinations in Afrobatrachian frogs from the best-fit HiSSE model (HiSSE 19; Table 1). Squares at tips are colored by the observed character states (yellow: monochromatic, blue: sexually dichromatic), whereas node pie charts represent the probability of a state assignment to: 1) monochromatism + hidden state absent (yellow), 2) monochromatism + hidden state present (orange), 3) dichromatism + hidden state absent (blue), or 4) dichromatism + hidden state present (purple). No instance of the monochromatism + hidden state present is reconstructed on the phylogeny, whereas a transition to the dichromatism + hidden state present combination is inferred once in the MRCA of two monotypic genera (Cryptothylax, Morerella), indicating a near absence of the hidden state across the entire tree.FigS5_HiSSE_All_States.pdfSupplemental Table 1Table S1. Taxon, voucher, and locality information for all samples included in the sequence-capture experimentTableS1_Sampling_Final.csvSupplemental Table 2Table S2. A summary of the occurrence of monochromatism and sexual dichromatism in Afrobatrachian species based on literature, museum specimens, and collective field observations. For color score, 0 indicates monochromatism and 1 indicates sexual dichromatism.TableS2_Dichromatism_Data.csv