Spatial and ecological population genetic structures within two island‐endemic Aeonium species of different niche width

Ecology and Evolution

David E. V. Harter⁴  Mike Thiv¹  Alfons Weig²  Anke Jentsch³ 

[1] State Museum of Natural History Stuttgart, Stuttgart, Germany;DNA Analytics and Ecoinformatics, BayCEER, University of Bayreuth, Bayreuth, Germany;Disturbance Ecology, BayCEER, University of Bayreuth, Bayreuth, Germany;Biogeography, BayCEER, University of Bayreuth, Bayreuth, Germany

关键词: Gene flow barriers;    island biogeography;    isolation by distance;    isolation by ecology;    landscape genetics;    niche width;   

DOI  :  10.1002/ece3.1682

来源: Wiley

【 摘 要 】

Abstract

The Crassulacean genus Aeonium is a well-known example for plant species radiation on oceanic archipelagos. However, while allopatric speciation among islands is documented for this genus, the role of intra-island speciation due to population divergence by topographical isolation or ecological heterogeneity has not yet been addressed. The aim of this study was to investigate intraspecific genetic structures and to identify spatial and ecological drivers of genetic population differentiation on the island scale. We analyzed inter simple sequence repeat variation within two island-endemic Aeonium species of La Palma: one widespread generalist that covers a large variety of different habitat types (Ae. davidbramwellii) and one narrow ecological specialist (Ae. nobile), in order to assess evolutionary potentials on this island. Gene pool differentiation and genetic diversity patterns were associated with major landscape structures in both species, with phylogeographic implications. However, overall levels of genetic differentiation were low. For the generalist species, outlier loci detection and loci–environment correlation approaches indicated moderate signatures of divergent selection pressures linked to temperature and precipitation variables, while the specialist species missed such patterns. Our data point to incipient differentiation among populations, emphasizing that ecological heterogeneity and topographical structuring within the small scales of an island can foster evolutionary processes. Very likely, such processes have contributed to the radiation of Aeonium on the Canary Islands. There is also support for different evolutionary mechanisms between generalist and specialist species.

【 授权许可】

CC BY   
© 2015 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.

Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.