15 The sub-alpine zones of oceanic islands are unique and dynamic ecosystems with high 16 levels of endemism, making them particularly suitable model systems in which to 17 investigate evolutionary and biogeographic processes. The sub-alpine flora of the Canary 18 Islands is restricted to the islands of Tenerife and La Palma. Its origins are poorly 19 understood. Echium wildpretii Hook.f. is an iconic species of the subalpine zones of these 20 two islands, with distinct subspecies recognised on each island. This study examines 21 patterns of genetic and morphological diversity in E. wildpretii to investigate the diversity 22 and evolution of the lineage. Nine microsatellite markers were designed and used to 23 investigate population genetic structure and patterns of gene flow within and between 24 islands and populations. Morphological characters were assessed to test the distinctiveness 25 of the two subspecies recognised. Strong genetic differentiation was observed between 26 islands with higher genetic diversity on the younger island of La Palma than on Tenerife.27 Very low levels of inter-island gene flow were observed indicating that these taxa are 28 reproductively isolated and evolving independently. Morphological analysis confirmed the 29 distinctiveness of plants from the two islands. Given their genetic and morphological

Animal mitogenomes are typically devoid of introns. Here, we report the largest number of mitochondrial introns ever recorded from bilaterian animals. Mitochondrial introns were identified for the first time from the phylum Bryozoa. They were found in four species from three families (Order Cheilostomatida). A total of eight introns were found in the complete mitogenome of Exechonella vieirai, and five, 17 and 18 introns were found in the partial mitogenomes of Parantropora penelope, Discoporella cookae and Cupuladria biporosa, respectively. Intron-encoded protein domains reverse transcriptase and intron maturase (RVT-IM) were identified in all species. Introns in E. vieirai and P. penelope had conserved Group II intron ribozyme domains V and VI. Conserved domains were lacking from introns in D. cookae and C. biporosa, preventing their further categorization. Putative origins of metazoan introns were explored in a phylogenetic context, using an up-to-date alignment of mitochondrial RVT-IM domains. Results confirmed previous findings of multiple origins of annelid, placozoan and sponge RVT-IM domains and provided evidence for common intron donor sources across metazoan phyla. Our results corroborate growing evidence that some metazoans with regenerative abilities (i.e. placozoans, sponges, annelids and bryozoans) are susceptible to intron integration, most likely via horizontal gene transfer.