A new paper pushing the theory that the area of a birds brain that controls movement is the same region that controls singing and learning to sing. It is the first study to use Molecular Mapping to examine the areas of a birds forebrain that control movement. Erich Jarvis suggests that ‘spoken language areas evolved out of pre-existing motor pathways’. Perhaps it is one possible reason why humans gesture with their hands as they are speaking. It is believed that the common ancestor of reptiles, birds and mammals, Amnitoes, shared similar motor pathways.
Cerebral systems that control vocal learning in distantly related animals evolved as specializations of a pre-existing motor system inherited from their common ancestor that controls movement, and perhaps motor learning.
The results back up claims that gestural language came before spoken language. Even now children are seen to gesture before they learn how to talk. ‘Gesturing is something that goes along naturally with speech. The brain areas used for gesturing may have been co-opted and used for speech’ says Erich Jarvis.
You can view & download the paper “Molecular Mapping of Movement-Associated Areas in the Avian Brain: A Motor Theory for Vocal Learning Origin” from PLoS ONE webiste.