Vocal learning is the substrate for human language. It is a rare trait that humans share with only three groups of birds and two other groups of mammals. By studying the brain pathways for vocal learning in birds and humans we hope to discover the genetic constraints under which vocal learning evolved. Knowledge of vocal learning pathways may lead to improved treatments for human brain injuries and language difficulties.
See paper “Learned Birdsong and the Neurobiology of Human Language” which appeared in the Annals of the New York Academy of Sciences in 2004.