• Tracking evolution across species: Researchers compared genome sequences from four bird groups that independently evolved to eat sugar-rich diets – hummingbirds, sunbirds, honeyeaters, and parrots – alongside their relatives that do not eat sugar, to find DNA differences linked to sugar eating.
• Patterns of change: Some genetic changes were unique to each group, but many were shared across two or more groups, including key genes involved in sugar processing and blood pressure regulation.
• Metabolic adaptation: Lab experiments confirmed genetic changes that enhance sugar processing – insights that may help researchers better understand how animals evolved to thrive on high sugar diets.