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- Mammoths of truth: scientists have found a new reason for the extinction of ancient giants
Mammoths of truth: scientists have found a new reason for the extinction of ancient giants
Scientists from several countries conducted a large-scale study of the remains of mammoths that lived in different eras. In total, about 500 samples were studied, which ranged in age from 1.1 million to 4 thousand years. One of the achievements of scientific work was the identification of traces of pathogenic microbes. Similar species also cause deadly epidemics in modern African elephants. The discovery suggested that bacteria could be one of the causes of mammoth extinction. For more information, see the Izvestia article.
How ancient pathogens were separated from modern pollution
Russian scientists, as part of a large international team, conducted research that allowed them to take a fresh look at the causes of mammoth extinction.
The Russian side was represented in the scientific work by the staff of the Zoological Institute of the Russian Academy of Sciences, the N. A. Shilo Northeastern Integrated Research Institute of the Far Eastern Branch of the Russian Academy of Sciences, and the Museum of Anthropology and Ethnography. Peter the Great (Kunstkamera) of the Russian Academy of Sciences, the Institute of Geology of the Russian Academy of Sciences and the Institute of Applied Ecology of the North of the Northeastern Federal University. In addition to them, scientists from Sweden, Denmark, France, Great Britain, Spain and Canada participated in the study.
— Every year, experts find details that expand our knowledge of mammoths, the largest representatives of glacial fauna. In particular, the discovery of bacterial genomes related to those that have recently caused the death of entire populations of African elephants in their bone remains has become a sensation," said Alexey Tikhonov, a leading researcher at the Laboratory of Theriology at the Zoological Institute (ZIN RAS), scientific secretary of the Mammoth Committee of the Russian Academy of Sciences.
During the work, the experts analyzed the genetic material extracted from mammoth bones, teeth and skin tissue. Their value, in particular, lies in the fact that these organs preserve the DNA not only of the host, but also of the microbes that lived in it at the time of the death of the individual, he explained.
A total of 483 genomic sets were studied. The earliest of them were more than 1 million years old, and the most recent specimens belonged to animals that lived on Wrangel Island (Russia) about 4 thousand years ago. To separate the bacteria that inhabited mammoth organisms during their lifetime from those that colonized their remains later, the researchers used special software methods.
As a result, scientists have discovered six groups of microbes that are contemporaries of mammoths, said Alexey Tikhonov. In particular, microorganisms were found in the remains of a 1.1 million-year-old steppe mammoth. This is the oldest DNA of a microbe related to an animal that has ever been found.
"Erysipelothrix bacteria are also notable among the finds," the scientist added. — These are pathogens of an infection that causes inflammation of the skin and joints. In modern history, these pathogens have provoked epidemics among African elephants several times, as a result of which individual populations simply died out.
How studying the genome will change views on the causes of mammoth extinction
According to the researcher, the results obtained force us to look at the causes of mammoth extinction from a different angle. Previously, it was believed that the first factors on this list were global cooling and the extermination of ancient people. To these, it is probably worth adding epidemics that mowed down weakened and scattered herds of animals.
"The amazing possibilities of modern paleogenetics make it possible to understand the details of the genome structure of Ice Age animals and their smallest neighbors, microbes. This is done by mitogenomics— a science that studies what is left of nothing at all: fragments of the genomes of completely decayed organisms," explained Andrey Zhuravlev, professor at the Department of Bioevolution at the Faculty of Biology at Moscow State University.
According to him, the above study revealed traces of more than 300 bacteria and archaea. Most of them have already settled on the dead carcasses. Scientists also found representatives of the microbiome that helped mammoths digest food. A special group is represented by pathogenic microorganisms: Streptococci, which cause dental caries; erysipelothrix, which can affect joints and even heart valves, and pasteurella.
The latter could be transmitted from individual to individual, causing epizootics, the expert added. Just like, for example, among modern African elephants. However, do not think that mammoths became infected and died out from them. Pasteurellosis can lead to inflammation of the bronchi and damage to other organs, leading to death. But similar microbes accompanied mammoths throughout their evolution. And, probably, the animals have developed resistance to them.
— There is still no exact data on the causes of the death of mammoth fauna. Scientists agree that the process of extinction of the woolly mammoth, cave lion, bighorn deer, woolly rhinoceros and other animal and plant species was complex. Studying individual species in isolation from the ecosystem is pointless, since they contact and influence each other's evolution," said Artyom Nedoluzhko, scientific director of the paleogenomics laboratory at the European University in St. Petersburg.
The study of ancient microorganisms and their hosts, he added, is interesting in terms of parallel evolution. In this regard, it is important to draw attention to the research of Russian scientists.
In particular, the university staff, together with researchers from NEFU, studying the internal organs of the baby mammoth Yana in March 2025, discovered cysts of an unknown ancient pathogen. DNA analysis revealed its affinity with protozoa of the genus Aimeria. These organisms parasitize modern Asian elephants, which negatively affects programs to restore the number of animals.
—Further research should show," Artyom Nedoluzhko noted, "whether this paleoparasite has survived in the modern mammalian fauna of Northeastern Russia or has sunk into oblivion, just like its woolly host.
In addition, he added, it is known that the health and longevity of organisms largely depends on the species composition of their microbiota. Therefore, knowledge about the bacteria of extinct species is likely to increase the chances of the revival of ancient animals in the present.
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