Figure 4 From: Have giant lobelias evolved several times independently? Life form shifts and historical biogeography of the cosmopolitan and highly diverse subfamily Lobelioideae (Campanulaceae) Divergence time estimates using Penalized Likelihood. Mean age chronogram showing 95% confidence intervals of age nodes (bars), based on 1000 Bayesian trees from a post burn-in tree sample. The stars represent calibration points: C1, crown age of Asterales as estimated by Bremer et al. [66], fixed age = 93 Ma; C2, crown age of subfamily Campanuloideae, based on a fossil Campanula, minimal age = 5.33 Ma [68]; C3 -- C7, diversification of Hawaiian taxa, corresponding to the age of the oldest island of the Hawaiian Ridge (Kure) after which a continuous chain of islands has been available as 'stepping stones' for propagules of the Hawaiian biota, maximum age = 29.8 Ma [26].Back to article page