XVI International Botanical Congess

The refinement of techniques for the detection and analysis of DNA sequence variation has provided plant evolutionary biologists with the necessary tools for the inference of historical patterns of migration and dispersal. The high levels of intraspecific variation, restricted vagility of seed propagules, and the presence of palynological data bases make many plant species ideal model systems for phylogeographic studies. Nested clade analyses of several herbaceous species in southeastern North America provide examples of past fragmentation, range expansion, long distance dispersal, and colonization. Phylogeographic investigations of the contribution of historical events to contemporary distributions of genetic variation provide insights into the processes of intraspecific diversification and speciation.