Scientists have sequenced the world's oldest DNA from a mammoth that lived in the Siberian steppe more than a million years ago. The previous record-holder for most ancient DNA was from a horse that lived between 560,000 and 780,000 years ago.
"This DNA is incredibly old. The samples are a thousand times older than Viking remains and even pre-date the existence of humans and Neanderthals," told CNN Love Dalen, a professor of evolutionary genetics at the Centre for Palaeogenetics in Stockholm.
The researchers investigated DNA from molars from three separate mammoths found in the Siberian permafrost in the 1970s. What they found was a potentially new type of mammoth species previously unknown to us.
"This came as a complete surprise to us. All previous studies have indicated that there was only one species of mammoth in Siberia at that point in time, called the steppe mammoth," told CNN study co-author Tom van der Valk, a postdoctoral researcher at the Swedish Museum of Natural History.
The researchers further found certain traits in the animals associated with life in the freezing Arctic. "Finally, we show that the majority of protein-coding changes associated with cold adaptation in woolly mammoths were already present one million years ago. These findings highlight the potential of deep-time palaeogenomics to expand our understanding of speciation and long-term adaptive evolution," wrote the researchers in their study.
However, sequencing the ancient DNA was no easy task. The sample had been degraded into very small pieces that the researchers had to put together sort of like a puzzle.
They claimed that there were more than a billion pieces. To perform this complicated task, they made use of a detailed genome from a living African elephant. This resulted in a sample that was viable enough to be analyzed.
The research is published in the journal Nature.