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Si us plau utilitzeu sempre aquest identificador per citar o enllaçar aquest document: https://hdl.handle.net/2445/99480
Evolutionary history and drivers of diversification of the Mediterranean Nemesiidae spiders (Araneae, Mygalomorphae) = Història evolutiva i mecanismes de diversificació en aranyes mediterrànies de la familia Nemesiidae (Araneae, Mygalomorphae) = Historia evolutiva y mecanismos de diversificación en arañas mediterráneas de la familia Nemesiidae (Araneae, Mygalomorphae)
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[eng] Mygalomorphs is a cosmopolitan group that inhabits all the continents except Antarctica. The group and has been commonly described as ‘primitive’ because of the retention of plesiomorphic characters, such as the presence of four book lungs and chelicerae bearing longitudinal fangs with unsynchronized movement. Those spiders have a cryptic lifestyle. They are nocturnal, ground-dwellers and construct buried silk burrows that are hidden by a closing a trapdoor. Females are mostly sedentary, long-lived, and they live in the burrow their whole life, whereas adult males have annual life cycles, and spread after the first mault searching for mates and mediate gene flow among populations. The low vagility, the long-life cycles, the narrow ecological preferences and the species restricted distribution makes mygalomorphs an excellent model system for biogeographic studies (Hedin et al. 2013; Raven 1980). This is due to the fact that ancient lineages with narrow habitat preferences and poor dispersal abilities are more likely to mirror the fingerprint of geological history (Stock, 1993; Bauzà-Ribot, 2013). Previous molecular studies indicate that they have extreme geographic structure. Low vagility has largely been cited as the main reason for the high level of local endemism in mygalomorph populations and species. Most of the closely related taxa are usually morphologically homogeneous and conserved (Bond & Hedin 2006). Diagnostic characters for species taxonomy are based on reproductive organs of adult males, but adults males spreads in a very concrete period of the year, that may vary depending on the environmental conditions, so the predominant sex obtained by direct capture are females o juveniles. This make extremely complicated the species identification because most of the taxonomic descriptions are old, inaccurate and based only on males, besides that females are unknown in most cases. There are six mygalomorph families present in the Western Mediterranean; the most diverse is the family Nemesidae , specially the genus Nemesia is extremely diverse with more than 50 species. In this thesis we investigated the origins and drivers of diversification of this genus. This study includes the first molecular phylogeny that confirmed that Nemesia and Iberesia are sister groups. Also we demonstrated high levels of sub-generic diversity, and the existence of putative species awaiting formal description . This sub-generic diversity is closely related with the degree of reduction of the spinnerets, that has been proved that contains phylogenetic signal and influences the architecture of the Burrows. The broke of the hercynian belt, and subsequentment rotation of the plates together with the isolation during Tortonian of the Betic-Rif area and the Messinian Salinity Crisis have been pointed out as major drivers of diversification in the region. At the same time we investigated the process that allowed those spiders to colonize Balearic Archipelago, the most isolated in the Mediterranean Region, our results showed that vicariance processes occurred during early Tortonian Marine Regression allowing the colonization from their origin in the Betic area. We applied integrative approaches to study patterns of high overlooked diversity in Tunisa, and 12 new species are described. We also try to decipher the mechanisms of coexistence of the genus. After two years of monitoring, our results show that coexistence is maintained by spatial and temporal segregation. Every specie has a maximum dispersal peak that doesn’t overlaps with other species, and furthermore those spiders have a strong habitat selection.
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MORA DE CHECA, Elisa. Evolutionary history and drivers of diversification of the Mediterranean Nemesiidae spiders (Araneae, Mygalomorphae) = Història evolutiva i mecanismes de diversificació en aranyes mediterrànies de la familia Nemesiidae (Araneae, Mygalomorphae) = Historia evolutiva y mecanismos de diversificación en arañas mediterráneas de la familia Nemesiidae (Araneae, Mygalomorphae). [consulta: 29 de novembre de 2025]. [Disponible a: https://hdl.handle.net/2445/99480]