The Evolution of Egg Shape

Egg shape is related to the bird's flight ability. As birds become more powerful flyers over evolutionary time, they also become more streamlined. So in Cassie's new hypothesis, narrow sleek strong flyers needed to lay skinnier, longer or asymmetric eggs through their narrower sleeker pelvis. Where is ours? Which are kind of chunky. They have round eggs like ping pong balls. This strong flyer shape match seems to map onto the data in the broadest sense, but Cassie says it probably won't explain all the variety in egg shapes.