Full text
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| Author(s): |
Daniel Caetano da Silva
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2011-05-26 |
| Examining board members: |
Glauco Machado;
Fernando Barbosa Noll;
Ricardo Pinto da Rocha
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| Advisor: | Glauco Machado |
| Abstract | |
The order Opiliones has almost 6000 species divided in four suborders and 45 families. Among these families, Gonyleptidae is well-known by its high diversity and because it concentrates the majority of the publications on harvestman ecology and behavior. We took advantage of this information to reconstruct the phylogeny of the gonyleptid subfamilies and discuss evolutionary patterns within the family based on the resulting topologies. The terminal species include 31 taxa, four belonging to the external-group (Stygnidae, Manosbiidae, and Cosmetidae), and 27 to the internal-group, which contains representatives of 14 of the 16 gonyleptid subfamilies (except Ampycinae and Gonyassamiinae). We performed the analyses using three distinct weighting schemes: equally weighted characters, successive weighting, and implied weighting. We coded 48 characters comprising 72 derived states, which makes the present study the largest ecological and behavioral phylogenetic data matrix published so far. The equal weighted analysis resulted in a single poorly resolved consensus tree, but this tree was compatible with the single most parsimonious successive weighted tree and with one of the two most stable trees obtained with implied weighting. Considering only the non-linear weighting schemes, Gonyleptidae is a monophyletic group, sister to Cosmetidae, based on a single non-homoplastic behavioral synapomorphy (male fights using the fourth pair of legs). We recovered the monophyly of five subfamilies that have already been revised using morphological characters: Hernandariinae, Goniosomatinae, Mitobatinae, Tricommatinae, and Heteropachylinae. We also obtained support for a well-recognized clade composed of the subfamilies Hernandariinae, Gonyleptinae, Sodreaninae, Progonyleptoidellinae, and Caelopyginae. However, we did not find support for the monophyly of Gonyleptinae, Sodreaninae, and Progonyleptoidellinae. High consistence indexes, in association with high Bremer and bootstrap support values for several clades (mainly subfamilies), clearly indicate that behavior and ecology provide phylogenetically informative characters. For that reason, they should be considered in future phylogenetic studies within Opiliones. Even though behavioral and ecological characters have already been used in other cladistic studies, this is the first time that the monophily of an arthropod family is formally demonstrated using exclusively non-morphological or non-molecular characters. (AU) | |