Incipient ecological speciation between successional varieties of a dominant tree involves intrinsic postzygotic isolating barriers.

ABSTRACT: Whereas disruptive selection imposed by heterogeneous environments can lead to the evolution of extrinsic isolating barriers between diverging populations, the evolution of intrinsic postzygotic barriers through divergent selection is less certain. Long-lived species such as trees may be especially slow to evolve intrinsic isolating barriers. We examined postpollination reproductive isolating barriers below the species boundary, in an ephemeral hybrid zone between two successional varieties of the landscape-dominant Hawaiian tree, Metrosideros polymorpha, on volcanically active Hawai'i Island. These archipelago-wide sympatric varieties show the weakest neutral genetic divergence of any taxon pair on Hawai'i Island but significant morphological and ecological differentiation consiste

SUBMITTER: Stacy EA 

PROVIDER: S-EPMC5395442 | biostudies-literature | 2017 Apr

REPOSITORIES: biostudies-literature