1. School of Mathematical ScienceYangzhou University 225002 Yangzhou China
2. Department of Mathematics and Mathematical StatisticsUmeå University SE‐90187 Umeå Sweden
3. Department of Ecology and Environmental ScienceUmeå University SE‐90187 Umeå Sweden
4. Theoretical Population Ecology and Evolution Group, Department of BiologyLund University 22362 Lund Sweden
5. Department of Ecology and Genetics, Animal Ecology, Science for Life LaboratoryUppsala University 75236 Uppsala Sweden
6. Evolution and Ecology ProgramInternational Institute for Applied Systems Analysis A‐2361 Laxenburg Austria