Beast 2 App Launcher Does Not Work In Mac Os.BEAST 2 includes a graphical user-interface for setting up standard analyses and a suit of programs for analysing the results. BEAST 2 uses Markov chain Monte Carlo (MCMC) to average over tree space, so that each tree is weighted proportional to its posterior probability. It can be used as a method of reconstructing phylogenies but is also a framework for testing evolutionary hypotheses without conditioning on a single tree topology. It estimates rooted, time-measured phylogenies using strict or relaxed molecular clock models. BEAST 2 is a cross-platform program for Bayesian phylogenetic analysis of molecular sequences.