All that Glisters is not Galled

TL;DR

This paper clarifies the relationships among four different definitions of galled trees and related evolutionary networks, unifying various concepts used in phylogenetics research.

Contribution

It establishes the precise relationships between four main definitions of galled trees and related networks in evolutionary biology.

Findings

Unified the definitions of galled trees and related networks.

Clarified the hierarchy among different types of evolutionary networks.

Provided a comprehensive framework for future research in phylogenetics.

Abstract

Galled trees, evolutionary networks with isolated reticulation cycles, have appeared under several slightly different definitions in the literature. In this paper we establish the actual relationships between the main four such alternative definitions: namely, the original galled trees, level-1 networks, nested networks with nesting depth 1, and evolutionary networks with arc-disjoint reticulation cycles.