Maximum likelihood phylogeny reconstructed from a 94-kb alignment of 118 concatenated orthologous exons present for all 12 mammals. The log-likelihood of the phylogram is lnL = -407,623.4, and estimates of model parameters are: %A = 25.9, %C = 27.0, %G = 25.0, and %T = 22.1 for base frequencies ; A-C = 1.29, A-G = 4.69, A-T = 0.72, C-G = 1.21, C-T = 5.75, and G-T = 1.00 for GTR relative substitution rates ; INV = 31.7% for the fraction of invariable sites, and α = 0.74 for rate heterogeneity among the remaining sites. Values on nodes are ML bootstrap support. Sequences from the 12 taxa were in silico recovered from assembled EnsEMBL genomes. The outgroup Monodelphis is drawn with midpoint rooting. Horizontal branch lengths are proportional to the DNA divergence (scale = 0.05 nucleotide substitutions per site).