 The tree of life is a representation of species in the form of lineage relationships, or at least that is how it is commonly interpreted (Ragan 2009; O’Malley et al. 2010). By making inferences from present-day data back to ancestral states, including common ancestry and divergence points, evolutionary biologists can build phylogenies, which not only capture evolutionary relationships but also give them approximate dates. Phylogenies have traditionally been constructed on the basis of morphological data, including fossils, but the last few decades have seen the rapid rise of molecular phylogenies. The use of gene and protein sequences, plus computational methods, has allowed far finer grained and more extensive reconstructions of all life on the tree (including organisms with limited morphological characters, such as microbes and fungi).