Constructing and Employing Tree Alignment Graphs for Phylogenetic Synthesis

TL;DR

This paper establishes a formal foundation for Tree Alignment Graphs (TAGs) in phylogenetics, enabling construction of consensus trees and supertrees from multiple input trees with diverse leaf labels.

Contribution

It provides a new, order-independent formal definition of TAGs and algorithms for constructing consensus and supertrees, advancing phylogenetic data integration.

Findings

Order-independent formalization of TAGs

Algorithms for majority-rule and strict consensus trees

Method to determine compatibility and construct supertrees

Abstract

Tree alignment graphs (TAGs) provide an intuitive data structure for storing phylogenetic trees that exhibits the relationships of the individual input trees and can potentially account for nested taxonomic relationships. This paper provides a theoretical foundation for the use of TAGs in phylogenetics. We provide a formal definition of TAG that - unlike previous definition - does not depend on the order in which input trees are provided. In the consensus case, when all input trees have the same leaf labels, we describe algorithms for constructing majority-rule and strict consensus trees using the TAG. When the input trees do not have identical sets of leaf labels, we describe how to determine if the input trees are compatible and, if they are compatible, to construct a supertree that contains the input trees.