Gene switch changed fruit fly courtship behavior

A single gene switch enabled fruit flies to adopt a new courtship behavior, demonstrating how minor brain rewiring drives evolutionary change. Researchers genetically transferred a gift-giving courtship ritual from one fruit fly species to another by activating a gene in insulin-producing neurons, creating new neural connections. This study, published August 14, 2025, in Science, suggests that behavioral evolution can stem from rewiring existing neurons, not just new ones.