 This means that exhaustive evaluation of all possible hypotheses very quickly becomes all but impossible—even as our capacity for this has grown with increased computing power. Finding the most parsimonious tree, the maximum likelihood tree, and even doing a multiple sequence alignment to begin with are all NP-complete  problems[7]  (Graham &amp; Foulds 1982; Wang &amp; Jiang 1994; Chor &amp; Tuller 2005). Bayesian inference is similarly computationally intractable (Ronquist, Mark, &amp; Huelsenbeck 2009).