A new paper in Evolution by research associate Leonardo Campagna explores the genomic mechanisms that have led to the evolution of flightlessness in the Patagonian steamer ducks. The different steamer duck species vary in their morphology, representing a continuum between the conditions allowing flight and those resulting in flightlessness. Whereas most transitions from flight to flightlessness have happened relatively deep in bird evolution, the steamer ducks represent a rare case in which this process can be studied while it is still in action. The study identifies two narrow candidate genomic regions implicated in the morphological changes that led to flightlessness. The strongest association is with DYRK1A, a gene that when knocked out in mice leads to alterations in growth and bone morphogenesis.
Here is a commentary on the paper from Nature.