Distinguishing Phylogenetic Level-2 Networks with Quartets and Inter-Taxon Quartet Distances

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Holtgrefe, Niels, Allman, Elizabeth S., Baños, Hector, van Iersel, Leo, Moulton, Vincent, Rhodes, John A., Wicke, Kristina
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866909839059320832
author Holtgrefe, Niels
Allman, Elizabeth S.
Baños, Hector
van Iersel, Leo
Moulton, Vincent
Rhodes, John A.
Wicke, Kristina
author_facet Holtgrefe, Niels
Allman, Elizabeth S.
Baños, Hector
van Iersel, Leo
Moulton, Vincent
Rhodes, John A.
Wicke, Kristina
contents The inference of phylogenetic networks, which model complex evolutionary processes including hybridization and gene flow, remains a central challenge in evolutionary biology. Until now, statistically consistent inference methods have been limited to phylogenetic level-1 networks, which allow no interdependence between reticulate events. In this work, we establish the theoretical foundations for a statistically consistent inference method for a much broader class: semi-directed level-2 networks that are outer-labeled planar and galled. We precisely characterize the features of these networks that are distinguishable from the topologies of their displayed quartet trees. Moreover, we prove that an inter-taxon distance derived from these quartets is circular decomposable, enabling future robust inference of these networks from quartet data, such as concordance factors obtained from gene tree distributions under the Network Multispecies Coalescent model. Our results also have novel identifiability implications across different data types and evolutionary models, applying to any setting in which displayed quartets can be distinguished.
format Preprint
id arxiv_https___arxiv_org_abs_2507_17308
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Distinguishing Phylogenetic Level-2 Networks with Quartets and Inter-Taxon Quartet Distances
Holtgrefe, Niels
Allman, Elizabeth S.
Baños, Hector
van Iersel, Leo
Moulton, Vincent
Rhodes, John A.
Wicke, Kristina
Populations and Evolution
Combinatorics
The inference of phylogenetic networks, which model complex evolutionary processes including hybridization and gene flow, remains a central challenge in evolutionary biology. Until now, statistically consistent inference methods have been limited to phylogenetic level-1 networks, which allow no interdependence between reticulate events. In this work, we establish the theoretical foundations for a statistically consistent inference method for a much broader class: semi-directed level-2 networks that are outer-labeled planar and galled. We precisely characterize the features of these networks that are distinguishable from the topologies of their displayed quartet trees. Moreover, we prove that an inter-taxon distance derived from these quartets is circular decomposable, enabling future robust inference of these networks from quartet data, such as concordance factors obtained from gene tree distributions under the Network Multispecies Coalescent model. Our results also have novel identifiability implications across different data types and evolutionary models, applying to any setting in which displayed quartets can be distinguished.
title Distinguishing Phylogenetic Level-2 Networks with Quartets and Inter-Taxon Quartet Distances
topic Populations and Evolution
Combinatorics
url https://arxiv.org/abs/2507.17308