Figure 2From: The bee tree of life: a supermatrix approach to apoid phylogeny and biogeographyMaximum-likelihood estimate of relationships among bee species. Circles at nodes represent bootstrap proportions after 100 nonparametric bootstrap replicates: black >=0.8, grey >=0.5. Nodes with bootstrap proportions less than 0.5 are without circles. Tips are unlabelled to reduce visual complexity; the labelled species tree is available in Newick format in Additional file 1.Back to article page