Ancient Mammoth Remains Contain earth's Oldest DNA, Unveiling Details about Early Microbial Existence

In a groundbreaking study led by researchers at the Centre for Palaeogenetics in Sweden, the oldest known host-associated microbial DNA from mammoths has been recovered and sequenced. The study, which analysed remains of both woolly and steppe mammoths, provides a unique look into the microbiomes of extinct giant animals.

The study, published recently, examined 483 mammoth remains, with some dating back approximately 1.1 million years. The team, led by Benjamin Guinet, a postdoctoral fellow at the Centre for Palaeogenetics and the lead author of the study, used a variety of sequencing methods to separate the ancient microbial DNA from modern contaminating DNA.

The analysis revealed the presence of six microbes living with woolly and steppe mammoths, including relatives of bacteria like Actinobacillus, Pasteurella, Streptococcus, and Erysipelothrix. One of the Pasteurella-related bacteria found in the study is closely linked to deadly outbreaks among African elephants.

Remarkably, the study found a partial genome of a bacterium called Erysipelothrix from a 1.1-million-year-old steppe mammoth. The team also managed to reconstruct partial genomes of a bacterium from a million-year-old mammoth tooth.

The presence of some groups of microbes spanned wide geographic ranges and a long evolutionary period, from over one million years ago to the extinction of woolly mammoths on Wrangel Island around 4,000 years ago. This suggests new possibilities to explore how host-associated microbes evolved in parallel with their hosts.

Guinet stated, "Ancient remains can preserve biological insights far beyond the host genome." The study's findings indicate that some groups of microbes lived alongside mammoths for hundreds of thousands of years.

The research is expected to reveal more about the health, ecology, and evolutionary challenges some of Earth's most impressive ancient creatures faced. As Guinet concludes, "This study pushes the study of microbial DNA back beyond a million years, opening up a whole new field of exploration."