Structural variation in context: mechanisms, functions and selection regimes across the tree of life

Genomic structural variants (SVs) are central to modern genetics. However, they do not fit easily into the simple classifications and analytical frameworks that work well for single‑nucleotide polymorphisms (SNPs). The papers in this special issue underscore that SVs cannot be treated as a homogeneous class, nor can their evolutionary consequences be inferred directly from their structural category alone. Instead, they compel us to engage explicitly with mutational mechanism, genomic context, and selection regime, and to recognize that the structural category only weakly predicts their functional and evolutionary impact.