1. Interfaculty Bioinformatics Unit University of Bern Bern 3012 Switzerland
2. Computational and Molecular Population Genetics Laboratory, Institute of Ecology and Evolution University of Bern Bern 3012 Switzerland
3. Swiss Institute for Bioinformatics Lausanne 1015 Switzerland
4. Current Address: Department of Integrative Biology Michigan State University East Lansing Michigan 48824