High-resolution Imaging, Positron Emission Tomography, and Phylogenetic Comparative Methods Reveal the Origin of the Avian Flight-Ready Brain

 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

 

 

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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.