Abstract Most microbes grow in spatially structured communities, and this profoundly shapes their ecology and evolution. At the microscale, short interaction ranges and steep nutrient gradients underlie cross-feeding, quorum sensing, and niche construction, generating spatial patterns that influence microbial behavior, community assembly, and stability. Here, we review theoretical and experimental evidence for how spatial organization drives eco-evolutionary processes, including founder effects during colonization, allele surfing during range expansion, emergent patterns that facilitate multilevel selection, and the exploration of rare epistatic genotypes. While the ecological and evolutionary consequences of spatial structure at the microscale are becoming clearer, linking these processes across scales to predict community- and ecosystem-level outcomes remains a major challenge. Addressing spatial interactions explicitly in microbiome research will be key. Recent advances in computational modeling, cultivation approaches, and omics now offer unprecedented opportunities to meet this challenge, providing fresh insights into how spatial structure governs the organization and dynamics of the microbial world across scales.
Bäcker et al. (Fri,) studied this question.