hylogenomic Analysis of Velvet Worms (Onychophora) Uncovers an Evolutionary Radiation in the Neotropic

Author(s)

Baker, Caitlin M. ^{[1, 2]} ; Buckman-Young, Rebecca S. ^[1] ; Costa, Cristiano S. ^[3] ; Giribet, Gonzalo ^[1]

Affiliation

^[1] Harvard Univ, Museum Comparat Zool, Dept Organism & Evolutionary Biol, Cambridge, MA 02138 - USA

^[2] Univ Wisconsin, Dept Integrat Biol, Madison, WI - USA

^[3] Univ Fed Mato Grosso, Inst Biociencias, Dept Biol & Zool, Lab Sistemat & Taxon Artropodes Terr, Cuiaba - Brazil

• Document type: Journal article
• Source: Molecular Biology and Evolution; v. 38, n. 12, p. 5391-5404, DEC 2021.
• Web of Science Citations: 0

Abstract

Onychophora ({''}velvet worms{''}) are charismatic soil invertebrates known for their status as a ``living fossil,{''} their phylogenetic affiliation to arthropods, and their distinctive biogeographic patterns. However, several aspects of their internal phylogenetic relationships remain unresolved, limiting our understanding of the group's evolutionary history, particularly with regard to changes in reproductive mode and dispersal ability. To address these gaps, we used RNA sequencing and phylogenomic analysis of transcriptomes to reconstruct the evolutionary relationships and infer divergence times within the phylum. We recovered a fully resolved and well-supported phylogeny for the circum-Antarctic family Peripatopsidae, which retains signals of Gondwanan vicariance and showcases the evolutionary lability of reproductive mode in the family. Within the Neotropical Glade of Peripatidae, though, we found that amino acid-translated sequence data masked nearly all phylogenetic signal, resulting in highly unstable and poorly supported relationships. Analyses using nucleotide sequence data were able to resolve many more relationships, though we still saw discordant phylogenetic signal between genes, probably indicative of a rapid, mid-Cretaceous radiation in the group. Finally, we hypothesize that the unique reproductive mode of placentotrophic viviparity found in all Neotropical peripatids may have facilitated the multiple inferred instances of over-water dispersal and establishment on oceanic islands. (AU)

• FAPESP's process: 14/20557-2 - Systematic and phylogenetic analysis of Epiperipatus Clark, 1913 (Onychophora: Peripatidae) based on molecular and morphological data
• Grantee: Cristiano Sampaio Costa
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• FAPESP's process: 11/20211-0 - Systematic and phylogenetic analysis of Epiperipatus Clark, 1913 based on molecular and morphological data (Onychophora, Peripatidae)
• Grantee: Cristiano Sampaio Costa
• Support Opportunities: Scholarships in Brazil - Doctorate