Geladas’ Adaptation to High Altitudes
Student Summary by Elizabeth Li
Original Source: Kenneth Chiou et al. Science Journal for Kids and Teens, October 2022
https://www.sciencejournalforkids.org/wp-content/uploads/2022/10/geladas_article.pdf; https://www.nature.com/articles/s41559-022-01703-4
Background: While animal species disperse throughout the world and adapt to their surroundings, many will find themselves in a habitat that could be undesirable or hostile to their ancestors. The gelada, a primate that lives on the Ethiopian Plateau, fits into this category of animal species. Although some animals adapt to lower oxygen levels through the process of increasing the amount of hemoglobin in their blood, the gelada seems to be different.
Objective: Scientists wanted to understand how geladas adapted to high altitudes as opposed to other species of animals.
Method: Researchers sedated wild geladas in northern and central Ethiopia, as well as zoo geladas, and collected blood and tissue samples from them. They measured the amount of hemoglobin in the geladas' blood and also their chest circumference. Then they used DNA-reading tools to map the geladas' DNA, comparing it to related species such as baboons and macaques.
Results: The study found that instead of the 21 chromosome pairs (a part of a cell that carries genetic information) that related species seemed to have, geladas had 22, with only northern Ethiopian geladas having the split chromosome. Moreover, scientists discovered that although hemoglobin in the geladas was shaped differently compared to that of other species, it did not carry more oxygen, meaning the hemoglobin didn't help them adapt. Instead, geladas were found to have bigger chest circumferences than baboons of the same size, which might mean they have larger lungs and individuals with larger lungs may have better adapted to the altitude.
Conclusion: The study found that geladas adapted to thin mountain air through their body shape rather than their blood. Instead of making more hemoglobin, they have bigger chests and possibly bigger lungs. Scientists also found that northern and central geladas are currently considered two subspecies, and the differences between them could mean they are on their way to becoming different species. Knowing how animals such as geladas adapted to low oxygen levels and high altitudes could help scientists discover new treatments and learn more about natural adaptations.
