Wing-Assisted Incline Running and the Evolution of Flight

A NEW ARTICLE in Nature casts light on the evolution of flight. We know that some dinosaurs had feathers, and we know that Archaeopteryx descended from the dinosaurs and retains primitive features that would have been characteristic of the first birds. However, Archaeopteryx is capable of powered flight, although not as adept at flight as later birds. The question is how the ancestors of Archaeopteryx and other early birds made the transition to flight. The issue has largely been dominated by a dichotomy between the arborial (trees down) and cursorial (ground up) models.