Scientists Uncover 1 Million-Year-Old DNA in Woolly Mammoth Remains

Researchers have identified DNA dating back over one million years in the remains of woolly mammoths. This groundbreaking discovery, led by an international team from the Centre for Palaeogenetics in Sweden, includes some of the world’s oldest microbial DNA and provides insights into potential pathogens that may have affected these long-extinct creatures.

The study analyzed microbial DNA from 483 mammoth specimens, with 440 sequenced for the first time. Among these specimens was a steppe mammoth, which lived approximately 1.1 million years ago. Using advanced genomic and bioinformatic techniques, the researchers differentiated between microbes that coexisted with the mammoths and those that invaded after their death.

Dr. Benjamin Guinet, the study’s lead author, expressed the significance of these findings, stating, “Imagine holding a million-year-old mammoth tooth. What if I told you it still carries traces of the ancient microbes that lived together with this mammoth?” He emphasized that this research extends the study of microbial DNA over a million years, opening new avenues for understanding the evolution of host-associated microbes alongside their hosts.

Insights into Ancient Microbial Life

The team identified six microbial groups consistently associated with mammoth hosts, including relatives of Streptococcus, Actinobacillus, Pasteurella, and Erysipelothrix. They suggested that some of these microbes may have been pathogenic. Notably, one Pasteurella-related bacterium is closely related to a pathogen responsible for fatal outbreaks in African elephants. Given that African and Asian elephants are the closest living relatives of mammoths, the findings raise crucial questions about whether mammoths were also vulnerable to similar infections.

The researchers successfully reconstructed partial genomes of Erysipelothrix from the steppe mammoth, marking the recovery of the oldest known host-associated microbial DNA. Dr. Tom van der Valk, a senior author of the study, remarked, “As microbes evolve fast, obtaining reliable DNA data across more than a million years was like following a trail that kept rewriting itself.” He added that the research offers valuable insights into how microbes may have influenced adaptation, disease, and extinction in the ecosystems of the Pleistocene era.

Despite challenges in determining the exact impact of these microbes on mammoth health due to DNA degradation and limited comparative data, the study offers an unprecedented look into the microbiomes of these giant creatures. The findings were published in the journal Cell and indicate that some microbial lineages coexisted with mammoths for hundreds of thousands of years, spanning significant geographic ranges and evolutionary timescales.

A New Era in Understanding Extinct Species

Love Dalén, an expert in ancient DNA and Professor of Evolutionary Genomics at the Centre for Palaeogenetics, highlighted the implications of the research: “This work opens a new chapter in understanding the biology of extinct species. Not only can we study the genomes of mammoths themselves, but we can now begin to explore the microbial communities that lived inside them.”

Overall, this study not only sheds light on the lives of woolly mammoths but also enhances our understanding of the complex interactions between ancient species and their microbial companions.