My long-term goal is to decipher the
molecular mechanisms that construct, modify, and maintain neural circuits for
complex behavioral traits. One such trait is vocal learning, which is critical
for song in song-learning birds and spoken-language in humans. Remarkably,
although all are distantly related, we found that song-learning birds
(songbirds, parrots, and hummingbirds) and humans have convergent forebrain
pathways that control the acquisition and production of learned sounds. This convergent
anatomy and behavior is associated with convergent changes in multiple genes
that control neural connectivity and brain development, of which some when
mutated are associated with speech deficits. Non-human primates and vocal
non-learning birds have limited or no such forebrain vocal pathways, but yet
possess forebrain pathways for learning and production of other motor
behaviors. To explain these findings, I propose a motor theory of vocal
learning origin, in which brain pathways for vocal learning evolved by brain
pathway duplication of an ancestral motor learning pathway. Once a vocal
learning circuit is established, it functions similarly as the adjacent motor
learning circuits, but with some divergences in neural connectivity. To test
this hypothesis, we are attempting to genetically engineer brain circuits for
vocal learning. These experiments should prove useful in elucidating basic
mechanisms of speech and other complex behaviors, as well as their pathologies
Pfenning AR, Hara E, Whitney
O, Rivas MR, Wang R, et al., & Jarvis ED. Convergent
transcriptional specializations in the brains of humans and song learning birds.
346 (6215): 1333 & online 1256846-1
Whitney O, Pfenning
AR, Howard JT, Blatti
CA, et al., West AE,
& Jarvis ED. Core
and region enriched gene expression networks of behaviorally-regulated genes
and the singing genome. (2014) Science
1334 & online 1256780-1 to -11.
Mirarab S, Aberer AJ, Li B, et al., Gilbert MTP, & Zhang G. Whole
genome analyses resolve the early branches to the Tree of Life of modern birds.
(2014) Science 346 (6215):
CI & Jarvis ED. Birds,
primates, and spoken language origins: behavioral phenotypes and
neurobiological substrates. (2012) Front. Evol. Neurosci. 4(12):1-24.
Chabout J, Sarkar A, Dunson DB, Jarvis ED. Male
mice song syntax depends on social contexts and influences female preferences.
(2015) Front. Behavioral Neurosci. 9:76. 1-16.
Arriaga G, & Jarvis ED.
vocal communication system: are ultrasounds learned or innate? (2013) Brain
& Language 124:96-116.