Club EvMed Conversations: Keep calm and carry on diving: Autonomic adaptation in phocid seals.

This Club EvMed event occurred on 12/19/2025. Learn more about Club EvMed at https://clubevmed.org.

We know that phocid seals (the ‘true’ seals) often dive in continuous bouts. They can spend 90% of their time in the water submerged. This information clearly demonstrates that phocid seals are animals which live at depth, periodically returning to the surface to breathe, and not surface dwellers which only occasionally leave the surface to forage. As such, their short- to medium-term behaviour is greatly influenced by the fact that they are, more often than not, dissociated from access to basic life-sustaining resources. This view involves more than a semantic distinction: the adoption of this view is essential to the creation of more penetrating questions and investigation into the fundamental phenotypic adaptations of basic autonomic function that ultimately underpin this lifestyle. I will review and present data, demonstrating key adaptations in the seal autonomic nervous system, essential to balancing the economies of O2, CO2, and pH, with the demands of diving. I will also present collaborative work with Duke University, investigating the underlying genetic adaptations, that generate clinical pathophysiologies in humans, that may convey these essential positively selected phenotypic changes in the seal.