> it seems hard to evolve in a gradual way There seems to be 4 different hypotheses. So there is no consensus on this question. https://en.wikipedia.org/wiki/

> it seems hard to evolve in a gradual way There seems to be 4 different hypotheses. So there is no consensus on this question. https://en.wikipedia.org/wiki/Origin_of_avian_flight#Hypotheses https://en.wikipedia.org/wiki/Origin_of_avian_flight#Hypothe... A video about the "wing-assisted incline running" hypothesis: "The Origin of Flight--What Use is Half a Wing?" https://www.youtube.com/watch?v=JMuzlEQz3uo https://www.youtube.com/watch?v=JMuzlEQz3uo