Christopher M. Smith PhD
The Smith Lab investigates how changes in anatomy have shaped the biology and behavior of our evolutionary relatives and us. We are particularly interested in sensory and communicative systems that are poorly represented in the fossil record, but which played fundamental roles in how early humans moved through, perceived, and interacted with their environments. Our work revolves around three interconnected themes:
Hominin Sensory Ecology
How did our ancestors perceive and interact with their environments? Our lab investigates the evolution of sensory anatomy in hominins by integrating comparative anatomy, fossil evidence, 3D imaging, and sensory biomechanical modeling. Our research explores how changes in sensory biology relate to locomotion, behavior, ecology, and the emergence of distinctly human adaptations.
The inner ear of P. robustus specimen DNH 7 and comparisons to the modern human membranous labyrinth. From Smith et al., 2025
Evolution of the Primate Inner Ear
Primates exhibit remarkable diversity in positional and vocalization behaviors, particularly within the hominoid clade, which includes apes and humans. However, reconstructing the evolutionary transitions of these behaviors is challenging, mainly due to the incomplete fossil record. Our research approaches these problems through the lens of the inner ear, home to the sensory organs responsible for balance and hearing. Specifically, we are developing integrative methods for modeling the functional parameters of the primate otolithic organs, which are crucial for 3D spatial awareness and sensory integration within the ear. By doing so, we can gain better insights into the evolution of primate positional behavior and auditory capabilities.
Anthropoid vestibular morphology. The left image shows an anterolateral view of a left human inner ear. The membranous labyrinth is shown in green beneath a transparent bony labyrinth. The utricular (blue) and saccular (purple) regions of the vestibule are highlighted among great apes (right top row) and three species of other anthropoids (right bottom row). From Smith et al. 2024.
Reconstructing the Hidden Anatomy of Human Origins
Our lab combines traditional anatomical reconstruction with cutting-edge digital visualization to reconstruct the anatomy of our evolutionary ancestors and investigate how these approaches can deepen our understanding of human evolution. From physical casting, fossil reconstruction, and illustration to advanced imaging, 3D modeling, and digital visualization, we develop new ways to explore the structure and function of the human body across evolutionary time.
