Seal and sea lion brains have evolved to support volitional control of vocal behavior and learning

Seals and sea lions have highly developed volitional breathing control, to
which the phocid seals add vocal production learning, including mimicry.
Here, using histology and ex vivo dMRI tractography, we provide evidence
for a phylogenetic spectrum of accumulative neural adaptations supporting
aspects of volitional vocal control across pinnipeds. Otariids and phocid
seals, but not coyotes, have a direct connection between vocal motor
cortex and phonatory brainstem nuclei. Harbor seals showed hypertrophic
connectivity between anterior ventrolateral thalamus and vocal premotor
cortex, part of a forebrain circuit related to vocal learning in birds and
mimicry in humans and parrots. We argue that Phocid seals have
auditory-premotor pathways potentially related to developmental call
learning.