 Incorporating molecular data both encourages and is facilitated by the adoption of mathematical tools. We got a hint of that in the discussion of molecular clocks  (§1.2.2),  which use estimated rates of molecular evolution to estimate divergence times. Around the same time, Anthony Edwards and Luca Cavalli-Sforza—both students of R.A. Fisher—began thinking of phylogenetic inference as a problem for statistics. After initially working independently on the problem, they collaborated to produce what are perhaps the first set of papers presenting phylogenetic inference in a statistical framework (as attributed by (Felsenstein 2001, 2004); Edwards’ own recollections of this work can be found in Edwards (1996)).