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

Abstract

Aim Using 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. Location Tenerife, Canary Islands. Methods We 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. Results Our 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 conclusions Our 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.

Molecular phylogenetics of Micromeria (Lamiaceae) in the Canary Islands, diversification and inter-island colonization patterns inferred from nuclear genes

“…The latter species, shown to be sister to Micromeria in the Canary Islands in previous phylogenetic analyses (Bräuchler et al, 2005(Bräuchler et al, , 2010Puppo et al, 2014), was used as outgroup. Only one sample from the taxon inhabiting Lanzarote and Fuerteventura (M. varia subsp.…”

“…Curto et al (2012) identified the loci by comparing EST sequences from several Lamiaceae species to the Arabidopsis thaliana genome and designing primers targeting potential intron regions. These markers were also used in Puppo et al (2014) and details concerning sequence structure can be found in Table 3. Amplification was performed using HotStarTaq Plus Master Mix Kit (QIAGEN, Valencia, California, USA) with a final volume of 10ul and containing 1 U Taq DNA polymerase, 75 nmol MgCl 2 , 1 nmol of each dNTP, 4 nmol of each primer, and ca.…”

“…These findings suggest that Micromeria might be another example where adaptation to different habitats within an island might be the prevailing mechanism explaining species richness. On the other hand, multi-locus phylogenetic analyses showed that Micromeria species from Tenerife seemed to have undergone at least three phases of diversification, two on the palaeoislands and a more recent one in the young, central part of Tenerife (Puppo et al, 2014). This might indicate that diversification of Micromeria in Tenerife is influenced by ongoing adaptation to relatively recently originated habitats but also by the secondary contact of the palaeoislands caused by the elevation of the central Teide massif (Puppo et al, 2014).…”

“…On the other hand, multi-locus phylogenetic analyses showed that Micromeria species from Tenerife seemed to have undergone at least three phases of diversification, two on the palaeoislands and a more recent one in the young, central part of Tenerife (Puppo et al, 2014). This might indicate that diversification of Micromeria in Tenerife is influenced by ongoing adaptation to relatively recently originated habitats but also by the secondary contact of the palaeoislands caused by the elevation of the central Teide massif (Puppo et al, 2014). Micromeria thus is an interesting example where the relative importance of inter-island dispersal and adaptation as explanations for a genus' diversity on an archipelago can be compared.…”

A new species of Micromeria (Lamiaceae) from Köyceğiz (Muğla, southwest of Turkey)

“…According to the data of Bräuchler et al (2010), section Pineolentia and section Micromeria have the same clade, and this shows that they have a common ancestor. The data of Puppo et al (2014Puppo et al ( , 2015 Bräuchler et al (2010). M. cymuligera (from section Cymularia) is closer to the Madagascarian group.…”