A examine uncovered mummified mice on high-elevation Andean volcanoes, revealing that mammals can survive in excessive, Mars-like situations. This discovering challenges our understanding of vertebrate life’s physiological limits and prompts additional analysis into these mice’s survival mechanisms.
The barren, wind-blasted peaks of volcanoes within the Puna de Atacama, straddling Chile and Argentina, bear a placing resemblance to the Martian floor, characterised by a sparse environment and frigid situations. Located at staggering heights exceeding 6,000 meters, these summits have been beforehand considered inhospitable for mammalian existence. Nevertheless, a examine lately printed within the journal Present Biology presents a groundbreaking discovery: mummified mice present in these harsh landscapes, pushing the identified boundaries of vertebrate survival on our planet.
“Essentially the most stunning factor about our discovery is that mammals may very well be residing on the summits of volcanoes in such an inhospitable, Mars-like surroundings,” says senior writer Jay Storz, a biologist on the College of Nebraska, Lincoln. “Properly-trained mountain climbers can tolerate such excessive elevations throughout a one-day summit try, however the truth that mice are literally residing at such elevations demonstrates that we’ve underestimated the physiological tolerances of small mammals.”
This {photograph} reveals a member of a species of leaf-eared mouse known as Phyllotis vaccarum. Credit score: Marcial Quiroga-Carmona
Storz and his colleagues found the primary mouse mummy on the summit of Volcán Salín by likelihood once they stumbled throughout the desiccated cadaver on the fringe of a rock pile. However, now realizing what to search for, they quickly turned up others.
“As soon as my climbing companion and I began looking out by the remainder of the rocks, we discovered seven extra mummies on the identical summit,” Storz remembers.
They then began looking out systematically on the summits of all of the Andean volcanoes. To date, they’ve searched 21 volcano summits, together with 18 with elevations over 6,000 meters. All informed, they’ve discovered 13 mummified mice on the summits of a number of volcanoes with an elevation larger than 6,000 meters. In some circumstances, the mummies have been accompanied by skeletal stays of quite a few different mice.
Video displaying the positioning the place 4 mummies have been excavated from a web site on the summit of Volcán Púlar (6,233 m), Chile. Credit score: Jay Storz
Radiocarbon Courting and Genetic Evaluation
Radiocarbon relationship confirmed that the mummified mice discovered on the summits of two volcanoes have been just a few a long time previous at most. These from a 3rd web site have been older, estimated at 350 years previous at most. Genetic evaluation of the summit mummies demonstrated that they symbolize a species of leaf-eared mouse known as Phyllotis vaccarum, which is understood to happen at decrease elevations within the area.
“The invention of the mouse mummies on the summits of those freezing, wind-scoured volcano summits was an enormous shock,” Storz says. “Together with our live-capture data of mice on the summits and flanks of different high-elevation Andean volcanoes, we’re amassing increasingly more proof that there are long-term resident populations of mice residing at excessive elevations.”
This {photograph} reveals a member of the analysis workforce on the summit of Ojos del Salado, 6,893 m (Puna de Atacama, Chile-Argentina). Credit score: Mario Pérez Mamani
Exploring the Mysteries of Excessive-Altitude Mammalian Life
The discovering now raises vital questions, together with how mammals can reside in a barren world of rock, ice, and snow the place the temperatures are by no means above freezing, and there may be roughly half the oxygen accessible at sea stage. It’s not clear why the mice would have climbed to such heights. Over 500 years in the past, Incas have been identified to conduct human and animal sacrifices on the summits of some Andean peaks. Nevertheless, the researchers observe that the mummified mice from the volcano summits couldn’t have been transported there by the Incas, on condition that none are sufficiently old to have co-existed with them.
In ongoing work, the researchers are investigating whether or not the high-elevation mice have particular physiological traits that allow them to outlive and performance in low-oxygen situations. They’re conducting physiological experiments on captive mice that have been collected from excessive elevations to seek out out. They’re additionally persevering with their mountaineering surveys of small mammals on excessive Andean peaks in Argentina, Bolivia, and Chile.
“With our mountaineering organic surveys within the Andes, we hold making stunning new discoveries concerning the ecology of maximum high-elevation environments,” Storz says.
Reference: “Genomic insights into the thriller of mouse mummies on the summits of Atacama volcanoes” by Jay F. Storz, Schuyler Liphardt, Marcial Quiroga-Carmona, Naim M. Bautista, Juan C. Opazo, Timothy B. Wheeler, Guillermo D’Elía and Jeffrey M. Good, 23 October 2023, Present Biology.
DOI: 10.1016/j.cub.2023.08.081
This work was funded by grants from the Nationwide Institutes of Well being, the Nationwide Science Basis, the Geographic Society, and FONDECYT.