When
Where
Paul M. Gignac, PhD
Associate Professor
Cellular & Molecular Medicine
Associate Professor
School of Information
Director, Physician Assistant Anatomy
College of Health Sciences
Research Associate
American Museum of Natural History
https://arizona.zoom.us/j/84344307076
Title: High-resolution Imaging, Positron Emission Tomography, and Phylogenetic Comparative Methods Reveal the Origin of the Avian Flight-Ready Brain
Abstract: Taking to the air afforded theropod dinosaurs—the ancestors of modern birds—access to a range of ecological niches that fueled the remarkable diversity of extant avifauna. A significant contributor to this evolutionary success is thought to be the independent acquisition of a hyperinflated, mammal-like brain, up to 11 times larger than that of other living reptiles. This brain expansion has long been considered essential for coordinating the visual, vestibular, tactile, and motor functions required for powered flight. However, recent research by Gignac and colleagues suggests that the evolutionary relationship between the origin of avian flight and brain volumetric inflation is far more complex than previously understood.
This talk will explore the neurological origins of avian flight using a comparative neuroscience toolkit. By examining both fossils and living birds through computed tomography (CT), diffusible iodine-based contrast-enhanced CT, positron emission tomography, and phylogenetic comparative methods, Gignac and his team explore the history of avian functional neuroanatomy in unprecedented detail. They map the behavior of the avian brain during flight and trace the evolution of brain expansion across the dinosaur-bird transition. The talk will reveal how pulses of encephalization pre- and post-date the origin of flight, discuss the cerebellum’s critical role in the multi-sensory integration of flight behaviors, and conclude with the team’s next steps—highlighting how understanding the evolutionary history of the avian flight-ready brain may shed light on broader neural adaptations associated with complex behaviors in vertebrates.