1. Institute of Evolution and Department of Evolutionary and Environmental Biology, University of Haifa, Haifa 3498838 Israel
2. Mitrani Department of Desert Ecology, Blaustein Institutes for Desert Research, Ben Gurion University of the Negev, Sede Boqer Campus, Sede Boker 84990 Israel
3. Department of Plant Pathology and Weed Research, ARO, Volcani Center, Bet-Dagan 50250, Israel
4. Department of Biology and Division of Statistical Genomics, Washington University, St. Louis, MO 63130-4899 USA