In the remains of mammoths, paleontologists have found the DNA of different microbes and reconstructed the microbial communities that once lived in the body of the ice age giants. This genome comes from bacteria, some of which even lived thousands, others 1.1 million years ago. This makes it the world’s oldest traces of microbial DNA. The bacteria could have been digestive helpers, but also pathogens, which provides indications of the development and possibly the extinction of the mammoth.
Mammuts were once widespread in North America, Asia and Europe and lived on our planet for thousands of years, until they finally died out about 4000 years ago with the end of the last ice age. Her next relatives are the Asian elephants (Elephas Maximus). But how did the mammoth stars come about and how did the big pachyderms develop beforehand? What did the ice -time giants fed in their cold habitat and what pandemics were they haunted? To date, these questions have only been partially clarified.
Further information on this has now collected researchers around Benjamin Guinet from the Center for Paleogenetics in Stockholm. To do this, they analyzed 483 fossil samples of wool and steppe mammoths (Mammuthus primigenius and Mammuthus trogontherii). The teeth, bones and skin residues were found in the Yukon region of Alaska and Siberia and are between 1.1 million and 4607 years old. Guinet and his colleagues focused their analyzes on the DNA of the microorganisms contained in the mammoth samples and evaluated them with the help of bioinformatic techniques. In this way, they were able to distinguish which microbes existed in their bodies during the lifetime of the mammoths and which only entered their remains after the mammoth died.
The oldest bacteria inheritance found in Mammutfossil
The paleogenicists identified 310 microbes, which mostly populated the Mammut’s remains, including environmental bacteria such as Gelidibacter, Nitrobacter and Sulfuricella. Among the finds were also microorganisms from six groups that once appeared in the living mammoths and used them as a host. This microbioma included, among other things, bacteria of the genres Actinobacillus, Pasteurella, Streptococcus and Erysipelothrix. Some of these bacteria found the researchers in several mammoth samples of younger and much older date. This indicates that these microbial descent lines coexisted over hundreds of thousands of years with mammoths. Among the finds was the sub -genome of a bacterium of the genus Erysipelothrix, the Guinet and his colleagues isolated from a 1.1 million year old steppe mammoth. This means that it is the oldest ever recovered DNA of a microbe that lives in a host.
Among the bacteria were relatives of today’s microbes and species without still living cousins. For example, the researchers found ancient relatives of microbes that today occur in the digestive tract of pigs and cattle and help them fermentation of vegetable food. With the herbivorous mammoths, these bacteria could have taken on a similar task. However, the ice age microbes probably lived in the mouth rather than in the intestine of the mammoths, since they were only found in molars but no other fossils. The exact function of this and most other identified mammoth microbes remains unclear, the team emphasizes. Some microbes could also have been pathogens, as genomical comparisons suggest with the microbiome of today’s pachyderms. For example, one of the bacteria found is closely related to a pathogen that leads to fatal infections in today’s African elephants (Loxodonta Africana). Whether the microbes discovered once triggered similar infections in mammoths cannot be said with certainty, since the DNA samples were partially damaged and there are only a few comparison data.
Insight into the co-evolution of animals and their microbioma
With the genome data, the researchers can now better reconstruct which microbes once lived in the body of mammoths and how they influenced the evolution of their hosts. “Our results open up new opportunities to research how host -associated microbes have developed parallel to their hosts,” says Guinet. With the technology, however, not only the genomes of mammoths can be researched, but also the genome of other extinct animal species and their microbial communities. “Our results show that ancient remains can preserve biological findings far beyond the tavern, which opens up perspectives on how microbes have influenced ecosystems in Pleistocene,” says senior author Tom van der Valk from the Center for Paleogenetics.
Source: Benjamin Guinet (Center for Paleogenetics) et al.; Cell, DOI: 10.1016/J.Cell.2025.08.003
