Why is evolution hiding?

[Darkstar]

A lizard becomes a wingless bird began that evolves a wing why? Did the wing stub make the bird more adaptable to the environment.

In short, yes.

How would a bird pass this long-term plan to the millions of generations in order to keep the lighter bone plan progressing (hallow bones) to fly when hallow bones is a major disadvantage for anything that can't fly?

Why would that necessarily be a disadvantage?
http://rspb.royalsocietypublishing.org/c.../2193.full

Although largely unstudied in birds, the material properties of bone tissue can also contribute to bone strength and stiffness. In this study, I calculated the density of the cranium, humerus and femur in passerine birds, rodents and bats by measuring bone mass and volume using helium displacement. I found that, on average, these bones are densest in birds, followed closely by bats. As bone density increases, so do bone stiffness and strength. Both of these optimization criteria are used in the design of strong and stiff, but lightweight, manmade airframes. By analogy, increased bone density in birds and bats may reflect adaptations for maximizing bone strength and stiffness while minimizing bone mass and volume. These data suggest that both bone shape and the material properties of bone tissue have played important roles in the evolution of flight. They also reconcile the conundrum of how bird skeletons can appear to be thin and delicate, yet contribute just as much to total body mass as do the skeletons of terrestrial mammals.