Sugar rush: Genomics of extreme metabolic adaptations in nectar birds

Animals demonstrate an extraordinary diversity of metabolic adaptations. However, most of our knowledge about animal metabolism is limited to just a few model organisms, such as humans and mice. This leaves us unaware of the true limits and drivers of metabolisms in the animal kingdom. For example, some birds have evolved metabolic adaptations to rely almost entirely on sugar. This extreme diet would be impossible for humans to survive on without them developing type 2 diabetes and related metabolic problems. In order to understand how these birds adapted to this diet on the molecular, tissue, and organismal levels, we need to examine the birds themselves. In my talk, I will discuss how a single gene loss contributed to the evolution of sugar-feeding in the birds with the fastest metabolism on the planet: hummingbirds. I will also talk about how we used comparative genomics, transcriptomics, and functional tests to uncover the main targets of selection in evolution of adaptations to this extreme sugar-only diet in birds in general. Convergent adaptations to sugar feeding in birds relied on an intricate interplay of protein-coding and regulatory evolution, which is only now beginning to be understood in its complexity.