JULY 1, 2019
by Casey Mcgrath, Society for Molecular Biology and Evolution
Scientists have found that multiple hummingbird species have adapted to life at high altitudes in the Andes through distinct genetic mutations that nonetheless affect the same biochemical pathways. This suggests that while the details of molecular adaptation may differ at the amino acid and protein levels, there is predictability in evolution at the level of biochemical pathways.
The transition from living at low elevations to high elevations, such as those found in the Andes, Himalayas, and Tibetan Plateau, comes with many challenges. Extremely high elevations are associated with colder temperatures, increased exposure to ultraviolet radiation, and a lack of oxygen, which is 40% less abundant above 4,000 m than at sea level. Organisms that live at these elevations have developed specific adaptations that allow them to cope with these difficulties. For example, genetic analyses of humans living in the Andes and on the Tibetan Plateau have revealed changes in specific genes that enable them to deal with limited oxygen environments. However, it remains unclear whether such changes are generally predictable across different species or populations, or whether there is some flexibility in what changes occur. In a new article in Genome Biology and Evolution (Lim et al. 2019), a group of researchers from Stony Brook University, the University of New Mexico, and the Swiss Federal Research Institute set out to answer this question.