Alexandra Hoffmann

Table of contents

Research Interests

For a long time, the formation of new evolutionary lineages via natural hybridization and allopolyploidization has been considered nonexistent or at least insignificant in animal taxa. However, a growing number of fertile hybrid forms and species of hybrid origin has been identified in fish, amphibian and insect taxa within the last decades. Some exhibit alternative reproductive modes that allow "nature to make its way", even when the heterospecificity of parental genomes complicates normal meiosis in hybrid offspring. A rather complex pattern of allopolyploid hybridization shows one of the most widespread and successful amphibians in Europe, the Edible Frog Pelophylax esculentus, which is a natural hybrid between the pool frog P. lessonae and the marsh frog P. ridibundus. In some parts of its range, P. esculentus occurs only in diploid form and reproduces hemiclonally by back-crossing with its parental species. In other parts, polyploid Edible Frogs successfully interbreed by producing a mix of haploid and diploid gametes, which results in viable offspring and stable diploid-triploid populations both within and outside the range of the two parental species. My PhD research focuses on the population genetics, phylogenetic origin, geographic distribution and gamete production patterns of diploid-triploid P. esculentus populations across a large part of Europe. In two other subprojects I investigate the influence of genetic variation and ploidy - specifically the double homospecific genome in triploid individuals - on phenotypic variation expressed in male advertisement calls and territorial behavior.


Education and Professional Positions

2011 - 2014 Ph.D. student, Department of Evolutionary Biology and Environmental Studies, University of Zurich
2010 - 2011 Research Assistant, Department of Animal Biology, University of Pavia, Italy
2008 - 2010 Scholarship, University of Pavia, Italy. Project: effects of Short Rotation Forestry on environmental quality of agro-ecosystems and zoocoenosis diversity
2005 - 2007 M.Sc. in Management and Conservation of Natural Resources, University of Siena, Italy
2002 - 2005 B.Sc. in Natural Sciences, University of Siena, Italy