Mummified rats found at the top of Andean volcanoes, one of the harshest regions

Science Editorial, October 23 (EFE).- The peaks of Andean volcanoes are considered largely hostile to life, but now, a scientific team has once again confirmed the existence of long-eared mice more than 6,000 meters above sea level.

These are 13 ancient mummies whose description was published on Monday in the journal Current Biology and which join other living specimens found by the team of Jay Stowers, from the University of Nebraska-Lincoln (USA), a few years ago. Both confirm that these rodents can live at extraordinary altitudes.

“It is incredible” that any species of animal can survive and function in this barren, cold, and oxygen-poor environment, the researcher says, adding that even at the base of volcanoes rats live in an “extreme Martian environment.”

The magazine stated that this discovery expands the physiological limits of vertebrate life on Earth.

The university states in a statement that in the 1970s and 1980s, archaeologists discovered some rodent corpses during their trips to various Andean peaks, and at that time it was believed that the animals may have traveled with the Incas, who made pilgrimages to what they considered sacred places. .

It was thought that rats may have gotten into firewood or other supplies that the Incas carried up the cliffs or that were part of animal sacrifices.

But this hypothesis came into question when living specimens appeared, such as the one found by Storrs in 2020 at Lullailaco (6,739 metres), a volcano located on the border between Chile and Argentina. “No mammal has ever been found living at such an extreme altitude.”

The team now reports the discovery of 13 bat-eared mouse carcasses on the summits of three nearby volcanoes, Saline, Polar, and Copiapo; They are freeze-dried mummified specimens.

Most are a few decades old, but the four mummies found at Bolar are older, perishing at most 350 years ago.

Their mummified condition helped preserve their DNA, and researchers wondered whether their genomes could represent a distinct subpopulation. “Our genomic data suggests that mice found on the tops, sides or bases of volcanoes in the surrounding desert terrain are all one big happy family.”

Furthermore, they revealed that two pairs of mummies were closely related – perhaps brothers or fathers and children – and the same proportion of males as females.

Combined with the recent discovery of other living specimens and mouse burrows in the Atacama Puna highlands, “it appears that the long-eared mouse not only roams the volcanic peaks, but somehow lives on them,” Stowers describes.

Most small rodents spend much of their time, energy, and attention avoiding predators. “Sure if you’re hiding on top of a volcano at 6,000 metres, you’re at least safe from that, but you have other things to worry about.”

The scientist concludes that the reason for its rise to such extreme heights remains a mystery.

The team now hopes to identify the physiological adaptations that help the rodents live at 6,000 meters above sea level. Evie

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