2026/05/22 by Alexander Brandt, Guillaume Lavanchy, Vincent Mérel +8 · 1 voice
Agricultural and Biological Sciences · Biochemistry, Genetics and Molecular Biology · Earth and Planetary Sciences · #Chromosomal and Genetic Variations #Evolution and Genetic Dynamics #Evolution and Paleontology Studies
paper · doi:10.1073/pnas.2535700123
openalex publication_date 2026/05/22 · openalex created_date 2026/05/23 · openalex updated_date 2026/07/27
Many organisms reproduce through noncanonical 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 y) 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.