Genome evolution under asexuality

• Applicant: Dr. Jens Bast
• Subject Area: Evolution, Anthropology
• Term: from 2015 to 2018
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 310591186

Asexual reproduction is viewed as an evolutionary dead end because the lack of recombination and genetic exchange between individuals hampers the elimination of deleterious mutations and slows the rate of adaptation. Challenging these views, a few animals are ancient asexuals, raising the question of what singularities allowed them to persist and diversify in the absence of sex. Here, I propose to explore mechanisms of genome evolution and adaptation in asexual animals. Genome and transcriptome data from five independently-evolved asexual stick insects, including two ancient asexuals, will be analysed to identify evolutionary convergences and common trends of genome structures. Comparisons with closely related sexual lineages will allow disentangling differences in the genomic selection landscapes caused by asexuality from lineage-specific characteristics. I will first test theoretically predicted consequences of asexuality, including the reduced efficacy of selection and increased heterozygosity, and investigate mechanisms that might alleviate predicted negative effects of asexuality. I will then develop insights into mechanisms that can generate novelty in asexuals because genome evolution is not constrained by meiosis. By understanding how asexual genomes evolve over time, my project will provide some of the most useful information to date on one of the major questions in evolutionary biology: why have sex?

• DFG Programme: Research Fellowships
• International Connection: Switzerland
• Host: Professorin Dr. Tanja Schwander