Fig. 5

The evolution of biparental care forms. a Overlapping and complementary care plotted on the phylogeny using stochastic character mapping with the R package phytools⁷³. b Summary diagram of the transition rates across the three possible character states of biparental care from the RJ Multistate model of evolution. The sample sizes for each character state are reported; the arrows are scaled to reflect the magnitude of mean transition rates with the mean value also indicated. c Posterior distributions of the transition rates from the RJ Multistate model of evolution are shown as box plots for comparison and as posterior density plots for each transition rate alone. The central black dot in the box plots indicates the median, the box the upper and lower quartiles, the vertical lines the 95% credible intervals of the posterior distributions, and the filled dots beyond the lines indicate outlier estimates. Transition rates among character states in b and c are indicated as follows: complementary to no biparental care (qCN, grey), complementary to overlapping biparental care (qCO, blue), no biparental care to complementary care (qNC, red), no biparental care to overlapping care (qNO, blue), overlapping to complementary biparental care (qOC, red) and overlapping to no biparental care (qON, grey)