Have you ever wondered how the birds might have started flying? Who their ancestors were? There are approximately 10,000 species in the whole world and they all have evolved from something. They all have ancestors which we never looked at or wanted to learn about. There are many hypotheses about why and how the wings and the flight evolved over the years. Some hypotheses about how wings might have evolved are they evolved from arms used to capture small prey, evolved from gliding ancestors who began to flap their gliding structures to create thrust. The hypotheses that is most supported is the gliding as it’s reasonable.
There are many concepts about why and how flight in birds evolved. Some of the concepts about why they evolved are to escape from predators, to catch fast and flying preys, to migrate from place to place, gain excess to new resources or niche. The two main theories about how birds might have begun to flight are either from ground up (did flight evolve from a bipedal, cursorial, ground-dwelling ancestor?) or from the tress down (did flight evolve from a semi-bipedal, arboreal, leaping and gliding ancestor?). The problem is not how they evolved; it’s how the flight stroke evolved. To answer our question, some examples are birds and pterosaurs (flying reptiles). Pterosaurs were the first vertebrae to evolve and true fliers as proved by UC Berkeley 's Dr. Kevin Padian. They are derived from the bipedal, cursorial archosaur. Another successful and diverse group to evolve are birds. The birds did not exist two hundred million years ago. The first evidence was found in Germany about the origin of birds in 1861. It was a skeleton with long, bony tail, claw and teeth which was similar to reptile. It also had feathers and wings which suggested the name, Archaeopteryx, meaning ancient wing. It was the very first bird to be known. Archaeopteryx and birds share many features with a particular group
References: Vertebrate Flight. (n.d) from http://www.ucmp.berkeley.edu/vertebrates/flight/evolve.html