Concrete Genes: How Urban Architecture Shapes Avian Genomic Diversity

• Applicant: Dr. Anne-Céline Granjon
• Subject Area: Ecology and Biodiversity of Animals and Ecosystems, Organismic Interactions ; Evolution, Anthropology
• Term: since 2025
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 575389085

Urban spaces are common across the globe, creating habitats that expose organisms to novel selection pressures, such as impervious surface, chemical pollutants, elevated temperatures, noise and light pollution. While early research on urban evolutionary biology often considered cities as uniform entities, it is now clear that cities form a mosaic of heterogeneous habitats (from dense city centers through residential areas to urban parks), shaped by local planning decisions and political histories. It is now recognized that continuous measures of urbanization are better adapted to predict the effect of urbanization along a gradient, or even better, along multiple, replicated gradients of urbanization. Genetic diversity, being the source of adaptation and evolution, is an important metric, also in urban evolutionary biology: it can uncover population structure, connectivity, genetic differentiation and signals of selection or adaptation. Here, I will use population genomic datasets from two co-occurring songbirds, the blue tit (Cyanistes caeruleus) and the great tit (Parus major), sampled along replicated urbanization gradients across eight Polish cities. Combining a multi-city approach with a fine-scale pedigree dataset from a single urban population, I will address whether (a) urbanization drive consistent genome-wide patterns of genetic diversity, structure, and selection across species and cities; (b) specific alleles or genomic regions are transmitted more frequently than expected by chance, pointing to recent or ongoing selection; (c) the socio-political transformations of the 20th century left lasting genomic signatures on urban populations. Using multi-scale urban metrics with high-resolution genomic data and established population genomic methods, I will quantify genetic diversity, identify loci associated with urbanization as well as loci showing sign of selection in urban environments and across generations, and explore the impact of city planning on genetic diversity. This study will advance our understanding of the evolutionary consequences of urban life and provide new insights into how urban planning and historical legacies shape the genomic landscape of urban biodiversity.

• DFG Programme: WBP Position