New Algorithms on Rooted Triplet Consistency

Abstract

An evolutionary tree (phylogenetic tree) is a binary, rooted, unordered tree that models the evolutionary history of currently living species in which leaves are labeled by species. In this paper, we investigate the problem of finding the maximum consensus evolutionary tree from a set of given rooted triplets. A rooted triplet is a phylogenetic tree on three leaves and shows the evolutionary relationship of the corresponding three species. The mentioned problem is known to be APX-hard. We present two new heuristic algorithms. For a given set of m triplets on n species, the FastTree algorithm runs in O(mn^2) which is faster than any other previously known algorithms, although, the outcome is less satisfactory. The BPMTR algorithm runs in O(mn^3) and in average performs better than any other previously known approximation algorithms for this problem.