Phylogenomic analyses elucidate the evolutionary relationships of bats

Area of Science:

• * Mammalian evolutionary biology
• * Molecular phylogenetics and phylogenomics
• * Comparative genomics

Background:

• * The evolutionary placement of bats (order Chiroptera) within mammals has been a persistent challenge in molecular phylogenetics.
• * Disagreements exist regarding the monophyly of echolocating bats, impacting hypotheses on the evolution of echolocation.
• * Previous studies have yielded conflicting results due to potential methodological limitations.

Purpose of the Study:

• * To resolve the evolutionary relationships of bats within the mammalian tree of life.
• * To investigate the monophyly of laryngeal echolocating bats using genome-scale data.
• * To identify factors contributing to past phylogenetic uncertainties.

Main Methods:

• * Generation of novel bat genome data.
• * Application of model-based phylogenomic analyses accounting for evolutionary heterogeneity.
• * Robust statistical analyses to test phylogenetic hypotheses.

Main Results:

• * Bats are identified as an ancient sister group to a clade including carnivores, ungulates, and cetaceans, refuting a close relationship with odd-toed ungulates.
• * Genome-scale evidence supports the paraphyly of laryngeal echolocating bats, indicating echolocation likely evolved once.
• * Phylogenetic uncertainties are attributed to model misspecification, long-branch artifacts, and marker choice in prior studies.

Conclusions:

• * The evolutionary origin of bats is ancient and their placement is resolved within Laurasiatheria, sister to the clade of carnivores, ungulates, and cetaceans.
• * Laryngeal echolocation is likely a single evolutionary event, with echolocating bats being a paraphyletic group.
• * This study underscores the importance of advanced phylogenomic methods and careful experimental design for robust evolutionary inference.