 To summarize, we first discussed phylogenetic inference as it was typically done prior to around the 1990s. First, infer the history of a number of characters (for example, genes). Each of these histories is a particular, branching tree. Now assume that these histories are the same as the species history. It is this assumption that allows methods such as parsimony or likelihood to evaluate competing hypotheses. The species history is then also a branching tree even though we know that in general, this is a kind of idealization assuming that (1) that lineages split but do not fuse, (2) that information is not transferred between lineages , and (3) that splits are singular, simple events. Each of these assumptions turn out to be false.