William Éamon Callison

WILLIAM CALLISON, then a graduate student at Harvard University, Cambridge, Massachusetts, was awarded funding in April 2019 to aid research on “Ventilatory Adaptations in Peru: How Does Thoracic Ventilation Change in Response to High Altitude?”, supervised by Dr. Daniel Lieberman. Despite aerobic activity requiring up to tenfold increases in air intake, human populations in high_altitude hypoxic environments can sustain high levels of endurance physical activity. While these populations generally have relatively larger chest and lung volumes, how thoracic motions actively increase ventilation is unknown. This project shows that rib movements, in conjunction with chest shape, contribute to ventilation by assessing how adulthood acclimatization, developmental adaptation, and population_level adaptation to high_altitude affect sustained aerobic activity. We measured tidal volume, heart rate, and rib_motion during walking and running in lowland individuals from Boston (~35m) and in Quechua populations born and living at sea_level (~150m) and at high altitude (>4000m) in Peru. We found that Quechua participants, regardless of birth or testing altitudes, increase thoracic volume 2.0’2.2 times more than lowland participants (p<0.05). Further, Quechua individuals from hypoxic environments have deeper chests resulting in 1.3 times greater increases in thoracic ventilation compared to age_matched, sea_level Quechua (p<0.05). Thus, increased thoracic ventilation derives from a combination of acclimatization, developmental adaptation, and population_level adaptation to aerobic demand in different oxygen environments, demonstrating that ventilatory demand due to environment and activity has helped shape the form and function of the human thorax.