The influence of geological history on diversification in insular species: genetic and morphological patterns of Micromeria Benth. (Lamiaceae) in Tenerife (Canary archipelago)

Abstract

AbstractAimUsing phylogenetic and morphometric approaches, our study aims to understand the diversification process of the two groups of Micromeria species in Tenerife: the species restricted to the palaeoislands, and the species widely distributed in the younger part of the island.LocationTenerife, Canary Islands.MethodsWe calculated a calibrated phylogeny and a Neighbor‐Net network based on eight nuclear loci from 37 samples: 22 of the 8 species currently recognized in Tenerife, and 15 of their closest relatives occurring in neighbouring islands and continental populations. We performed a principal components analysis (PCA) of 27 morphological characters from 54 specimens sampled from Tenerife.ResultsOur phylogeny showed that the species from Tenerife can be subdivided into three main clades: one composed of the species inhabiting the palaeoisland of Anaga (M. teneriffae, M. glomerata and M. rivas‐martinezii); another composed of the species present in the palaeoisland of Teno (M. densiflora); and a third group that includes all the central species (M. hyssopifolia, M. varia, M. lachnophylla and M. lasiophylla). Morphometric analyses indicated two main groups corresponding to the palaeoisland species and the central ones.Main conclusionsOur study points to a relationship between the diversification in Micromeria and the geological history of Tenerife. We conclude that Micromeria first arrived in Anaga where it diversified, subsequently colonized Teno and from there occupied the central part, presumably after the formation of the Teide volcano. The species of Micromeria in Tenerife constitute an interesting example of how species diversification on oceanic islands can be shaped by the island's geological history, which probably contributed to the high levels of endemism on Tenerife.