Scientists had discovered the fact that the control of the speech and precise movements of the hands has evolutionary roots in the same area of the brain, which in fish is responsible for the control of movement in the water and generation of signals required in the social system.
Andrew bass from Cornell University argues that the group of researchers under his leadership, was able to establish the origins of behavioral relationships between speech and hand movements in humans.
This study of the early evolution have shown that the movement of the fins in fish play a significant role in intraspecific communication. And they managed this part of the brain, analogous to that in mammals and birds coordinates the production of the sounds.
Thus, it is possible to assert with confidence that there is a strong neural connection between gestures and speech.