Although
the brains of different species share myriad similarities,
they also differ in numerous respects. Our laboratory aims
to understand how and why those species differences arose.
To that end, we conduct two kinds of research. First, we
ask how brains of different species diverge in their
development. We ask, for instance, at what point in
development the brains of parrots become larger, relative
to body size, than the brains of other birds. The aim is to
determine what evolutionary changes in the cellular and
molecular mechanisms of development underlie the species
differences in adult brains. Ultimately, we intend to
manipulate development experimentally in order to mimic
some adult species differences in brains, and thus to test
our hypotheses about how evolution modified development.
Second,
we seek to understand the functional consequences of those
species differences in brain anatomy. Why, for instance, do
only parrots, songbirds, and hummingbirds have direct
projections from the forebrain to the brainstem vocal motor
neurons. Probably, they have those unusual projections
because they facilitate a bird’s ability to mimic sounds.
But why was it useful for parrots to become vocal mimics?
Our research has revealed that parrots probably evolved
vocal mimicry because female parrots prefer males that
share their calls. In the long run, we intend to construct
a comprehensive, mechanistic explanation of why parrots are
so “smart.” More generally, we seek to understand how and
why species differences in brain anatomy evolved.
