A Fast and Scalable Method for Inferring Phylogenetic Networks from Trees by Aligning Lineage Taxon Strings

TL;DR

This paper introduces ALTS, a fast and scalable algorithm for inferring minimal tree-child phylogenetic networks by aligning lineage taxon strings, overcoming previous computational limitations.

Contribution

The paper presents a novel algorithm that efficiently infers minimal tree-child networks from multiple phylogenetic trees using lineage taxon string alignment.

Findings

ALTS infers networks with many reticulations quickly

It handles up to 50 trees with 50 taxa in about 15 minutes

The method outperforms existing programs in speed and scalability

Abstract

The reconstruction of phylogenetic networks is an important but challenging problem in phylogenetics and genome evolution, as the space of phylogenetic networks is vast and cannot be sampled well. One approach to the problem is to solve the minimum phylogenetic network problem, in which phylogenetic trees are first inferred, then the smallest phylogenetic network that displays all the trees is computed. The approach takes advantage of the fact that the theory of phylogenetic trees is mature and there are excellent tools available for inferring phylogenetic trees from a large number of biomolecular sequences. A tree-child network is a phylogenetic network satisfying the condition that every non-leaf node has at least one child that is of indegree one. Here, we develop a new method that infers the minimum tree-child network by aligning lineage taxon strings in the phylogenetic trees. This algorithmic innovation enables us to get around the limitations of the existing programs for phylogenetic network inference. Our new program, named ALTS, is fast enough to infer a tree-child network with a large number of reticulations for a set of up to 50 phylogenetic trees with 50 taxa that have only trivial common clusters in about a quarter of an hour on average.