I have always thought that these birds as “tapaculo” dwelling that the forest floor with all the resources essential to their needs, however pesseriformes they have had forcing others to fly long distances, which will in some way that I am aware, have had to activate silent genes, through your nervous system that trigger in some way to activate these genes and to force the anatomy of the wing muscles to generate long distances to face, through a long period of evolution, or be due to random the great diversity that has sustained in nature?. It is strange. Will finally the activation of a gene or the need to activate behavior from survival these special groups of genes, to determine who we are. Maybe the first is the chicken after come the egg.