I took the above photo from 18,700 feet near the summit of Cotopaxi, an (active) volcano in the Ecuadorean Andes. We were suffering from a bit of exertional and hypoxic stress in this photo. On the other hand, native people of the Andes can cope with hypoxia at altitude better than us genetic lowlanders. How is this so? The evolutionary biology of high altitude peoples of the Andes, Himalayas, and Ethiopian Plateau is the topic for September 6th.

This week’s EvolutionMedicine podcast “Altitude Adaptation and Maladaptation” is here (optional):

A pattern often seen is that blood hemoglobin increases with higher altitude of residence

We will explore the different routes to physiologic adaptation to altitude in Tuesday’s class.

For discussion: How might gene-environment mismatch account for acute mountain sickness in Europeans? How many generations does it take to evolve solutions to the problem of living in a high altitude environment?

Readings (updated):

1. Beall An Ethiopian pattern of human adaptation to high-altitude hypoxia

“The results of this study suggest that Ethiopian high-altitude natives respond to hypobaric hypoxia differently than Andean or Tibetan highlanders.” p. 17218 Beall 2002

2. Storz Genes at High Altitude

“Andean residents at high altitude are also characterized by an elevated hemoglobin concentration. By contrast, Tibetans living at elevations of up to 4000 m present a hematological profile similar to what would be expected at sea level.” p. 40 Storz 2010.

3. National Geographic: Three high altitude people

Despite living at elevations wih low oxygen content, “the Ethiopian highlanders were hardly hypoxic at all,” Beall said. “I was genuinely surprised.” p. 2 NatGeo

4. Two routes to functional adaptation: Tibetan and Andean high-altitude natives Beall-2007

“High-altitude hypoxia may be an even stronger agent of natural selection than falciparum malaria.” p. 8659. Beall 2007.

Extra readings:

Beall Tibetan and Andean Patterns of Adaptation to High-Altitude Hypoxia

“Tibetan resting ventilation was roughly 50% higher than Amarya resting ventilation. For example male Tibetans had an average resting ventilation of 19.7 l/min compared to an average of 13.4 for male Amayra”  p. 204 Beall 2000

Biello How Tibetans enjoy the high life

Xing Adaptation and Maladaptation to Ambient Hypoxia: Andean Ethiopian, and Himalayan Patterns.

Mentioned in the podcast:

Outside magazine: Alex Lowe’s body found on Shishapangma

Categories: evolutionary medicine class podcasts

Joe Alcock

Emergency Physician, Educator, Researcher, interested in the microbiome, evolution, and medicine