title: The Opiliones tree of life: shedding light on harvestmen relationships through transcriptomics.
abstract: Opiliones are iconic arachnids with a Palaeozoic origin and a diversity that reflects ancient biogeographic patterns dating back at least to the times of Pangea. Owing to interest in harvestman diversity, evolution and biogeography, their relationships have been thoroughly studied using morphology and PCR-based Sanger approaches to infer their systematic relationships. More recently, two studies utilized transcriptomics-based phylogenomics to explore their basal relationships and diversification, but sampling was limiting for understanding deep evolutionary patterns, as they lacked good taxon representation at the family level. Here, we analysed a set of the 14 existing transcriptomes with 40 additional ones generated for this study, representing approximately 80% of the extant familial diversity in Opiliones. Our phylogenetic analyses, including a set of data matrices with different gene occupancy and evolutionary rates, and using a multitude of methods correcting for a diversity of factors affecting phylogenomic data matrices, provide a robust and stable Opiliones tree of life, where most families and higher taxa are precisely placed. Our dating analyses using alternative calibration points, methods and analytical parameters provide well-resolved old divergences, consistent with ancient regionalization in Pangea in some groups, and Pangean vicariance in others. The integration of state-of-the-art molecular techniques and analyses, together with the broadest taxonomic sampling to date presented in a phylogenomic study of harvestmen, provide new insights into harvestmen interrelationships, as well as an overview of the general biogeographic patterns of this ancient arthropod group.
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA rfernandezgarcia@g.harvard.edu.
authors.forename: Rosa
authors.identifier: 0000-0002-4719-6640
authors.initials: R
authors.lastname: Fernández
authors.affiliation: Department of Zoology, University of Wisconsin-Madison, 352 Birge Hall, 430 Lincoln Drive, Madison, WI 53706, USA.
authors.forename: Prashant P
authors.initials: PP
authors.lastname: Sharma
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.|Instituto Nacional de Pesquisas da Amazônia, Coordenação de Biodiversidade (CBIO), Avenida André Araújo, 2936, Aleixo, CEP 69011-970, Manaus, Amazonas, Brazil.
authors.forename: Ana Lúcia
authors.initials: AL
authors.lastname: Tourinho
authors.affiliation: Museum of Comparative Zoology, Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA ggiribet@g.harvard.edu.
authors.forename: Gonzalo
authors.identifier: 0000-0002-5467-8429
authors.initials: G
authors.lastname: Giribet
mesh_terms: D000818:Animals; D001097:Arachnida / Q000145:classification*; D005075:Biological Evolution; D010802:Phylogeny; D059467:Transcriptome
keywords: Arachnida; Cyphophthalmi; Dyspnoi; Eupnoi; Laniatores; phylogenomics