Genetic structure of Micromeria (Lamiaceae) in Tenerife, the imprint of geological history and hybridization on within‐island diversification. Issue 11 (20th April 2016)

• Record Type: Journal Article
• Authors: Puppo, Pamela; Curto, Manuel; Meimberg, Harald
• Is Part Of: Ecology and evolution. Volume 6:Issue 11(2016:Jun.)
• Page Start: 3443
• Page End: 3460
• Publication Date: 2016-04-20
• Subjects: Genetic structure -- hybrid zones -- island evolution -- Macaronesia -- microsatellites -- oceanic islands -- paleo‐islands -- SSR; Ecology -- Periodicals; Evolution -- Periodicals; 577.05
• DOI: 10.1002/ece3.2094
• Languages: English
• ISSNs: 2045-7758

Abstract

Abstract: Geological history of oceanic islands can have a profound effect on the evolutionary history of insular flora, especially in complex islands such as Tenerife in the Canary Islands. Tenerife results from the secondary connection of three paleo‐islands by a central volcano, and other geological events that further shaped it. This geological history has been shown to influence the phylogenetic history of several taxa, including genus Micromeria (Lamiaceae). Screening 15 microsatellite markers in 289 individuals representing the eight species of Micromeria present in Tenerife, this study aims to assess the genetic diversity and structure of these species and its relation with the geological events on the island. In addition, we evaluate the extent of hybridization among species and discuss its influence on the speciation process. We found that the species restricted to the paleo‐islands present lower levels of genetic diversity but the highest levels of genetic differentiation suggesting that their ranges might have contracted over time. The two most widespread species in the island, M. hyssopifolia and M. varia, present the highest genetic diversity levels and a genetic structure that seems correlated with the geological composition of the island. Samples from M. hyssopifolia from the oldest paleo‐island, Adeje, appear as distinct while samples from M. varia segregate into two main clusters corresponding to the paleo‐islands of Anaga and Teno. Evidence of hybridization and intraspecific migration between species was found. We argue that species boundaries would be retained despite hybridization in response to the habitat's specific conditions causing postzygotic isolation and preserving morphological differentiation. Abstract : We found that the species of Micromeria restricted to the older parts of Tenerife present lower levels of genetic diversity but highest levels of genetic differentiation suggesting that their ranges have contracted over time. The two most widespread species in the island present the highest genetic diversity levels and a genetic structure correlated with the geological composition of the island. Evidence of hybridization and intraspecific migration between species was found.