JULY 1,
2019
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.
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