Taking to the air afforded the ancestors of modern birds access to a previously unheralded range of environments, a fact that underlies their remarkable diversity (>10,000 known species). A significant part of this success is thought to have stemmed from the independent evolution of a mammal-like, hyper-inflated brain. Such a brain structure has long been considered necessary for coordinating the many aspects of powered flight, but this hypothesis that has not yet been tested. This study examines evolutionary changes in avian brain development using a wide range of techniques, including high-resolution computed tomography (CT) imaging, 3-D visualization of whole brains, and statistical shape analyses. By digitally sampling developmental series of brains from birds and other vertebrates, this project will test for coordinated shape changes in brain regions that share key functional pathways. This data will be used to determine whether evolutionary shifts in brain development have driven important structural evolution in adult avian brains. Correlation with the early evolution of flight behavior will also be investigated.
Data generated for this study will be archived on online repositories and made available to scientific and public spheres. For educational purposes, brain models will be 3-D printed and implemented in museum and school programs. The broader developmental patterns identified here will also be synthesized into the larger findings of the national "BRAIN" initiative, which seeks to greatly enhance the understanding of the complex, inner workings of the brain across all species and through evolutionary history.
