10.18453/rosdok_id00005578 Brandt, Alexander Alexander Brandt http://d-nb.info/gnd/1238919367 https://orcid.org/0000-0003-3742-7692 Department of Ecology and Evolution, University of Lausanne, Lausanne CH-1015, Switzerland Lavanchy, Guillaume Guillaume Lavanchy https://orcid.org/0000-0002-3340-7785 Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Mérel, Vincent Vincent Mérel https://orcid.org/0000-0002-2322-8193 Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Soldini, Luca Luca Soldini Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Massy, Morgane Morgane Massy Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Dumas, Zoé Zoé Dumas https://orcid.org/0000-0001-9014-8356 Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Gaudichau, Emelyne Emelyne Gaudichau Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Labédan, Marjorie Marjorie Labédan Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Pasquier Genoud, Falon Falon Pasquier Genoud Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Bastardot, Marc Marc Bastardot Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland Schwander, Tanja Tanja Schwander https://orcid.org/0000-0003-1945-5374 Department of Ecology and Evolution, University of Lausanne, UNIL Sorge, Le Biophore, CH - 1015 Lausanne, Switzerland University of Rostock 2026 570 Life science 2026 en https://purl.uni-rostock.de/rosdok/id00005578 urn:nbn:de:gbv:28-rosdok_id00005578-1 Many organisms reproduce through non-canonical modes such as parthenogenesis or hybridogenesis (clonal transmission of one parent’s chromosomes), but whether these arise abruptly or stepwise from each other remains unclear. We address this in the stick-insect genus Bacillus , which harbors several hybrid lineages with diverse reproductive modes. From haplotype-resolved phylogenies of >500 wild-caught individuals, we infer a single, recent (~8,000 years) origin of all hybrids. The ancestral hybrid reproduced via hybridogenesis, which subsequently diversified into parthenogenesis and, twice independently, into triploid lineages. Laboratory crosses recapitulate this trajectory, where each step facilitated the next. These findings reveal how a single genomic perturbation can act as a catalyst for evolutionary innovation, turning the loss of sex into a driver of diversification rather than a dead end.