A single Mid-Pleistocene long-distance dispersal by a bird can explain the extreme bipolar disjunction in crowberries (Empetrum).

ABSTRACT: The proposed age of the striking biogeographic disjunction between the Arctic and southernmost South America varies from more than 65 million to a few thousand years, but no estimates based on explicit models and molecular data are available. Here we address the origin of bipolarity in crowberries (Empetrum), which are heath-forming dwarf shrubs with animal-dispersed fruits. We apply a fossil-calibrated relaxed molecular clock to model sequence evolution in two nuclear low-copy and two plastid DNA regions from 41 individual plants (420 clones for the nuclear regions) representing the entire geographic distribution of crowberries. The plastid region matK and four fossil calibration points were used to infer the ages of the crowberry stem and crown groups. All analyses resolved three major c

SUBMITTER: Popp M 

PROVIDER: S-EPMC3081031 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature