0000000000656488
AUTHOR
Andreas Tribsch
Plant speciation in continental island floras as exemplified byNigellain the Aegean Archipelago
Continental shelf island systems, created by rising sea levels, provide a premier setting for studying the effects of geographical isolation on non-adaptive radiation and allopatric speciation brought about by genetic drift. The Aegean Archipelago forms a highly fragmented complex of mostly continental shelf islands that have become disconnected from each other and the mainland in relatively recent geological times (ca<5.2 Ma). These ecologically fairly homogenous islands thus provide a suitable biogeographic context for assessing the relative influences of past range fragmentation, colonization, gene flow and drift on taxon diversification. Indeed, recent molecular biogeographic studies…
Comparative phylogeography of the Veronica alpina complex in Europe and North America
The Veronica alpina complex comprises eight species of alpine habitats over a wide range of mountain systems in the Northern Hemisphere. The occurrence of sympatric species in the European and North American mountain systems allowed us not only to investigate the effect of the ice ages on intraspecific phylogeographical patterns and genetic diversity in different continents of the Northern Hemisphere, but also to compare these patterns in closely related species. Plastid DNA trnL-F sequences and AFLP (amplified fragment length polymorphism) fingerprints were used to infer the phylogenetic history of the group and phylogeographical patterns within species. Hybrid origin of tetraploid eastern…