World's oldest DNA sequenced from a mammoth that lived more than 1 million years ago
February 17, 2021. Summarized by summa-bot.
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A tooth from a mammoth that roamed the Siberian steppe more than a million years ago has yielded the world's oldest DNA sequence.
(CNN)A tooth from a mammoth that roamed the Siberian steppe more than a million years ago has yielded the world's oldest DNA sequence.
It's the first time that DNA has been recovered from animal remains more than a million years old.
Previously, the most ancient DNA sample was from a horse that lived between 560,000 and 780,000 years ago.
An international team of researchers was able to isolate DNA from molars from three separate mammoths collected from the Siberian permafrost in the 1970s.
The oldest mammoth tooth dated back to between 1. 2 million and 1. 65 million years ago.
Named the Krestovka mammoth after where it was found, the research showed that this particular type of mammoth diverged from other Siberian mammoths more than 2 million years ago.
All previous studies have indicated that there was only one species of mammoth in Siberia at that point in time, called the steppe mammoth," said study co-author Tom van der Valk, a postdoctoral researcher at the Swedish Museum of Natural History.
They also believe that it was mammoths belonging to this previously unknown lineage that colonized North America some 1. 5 million years ago.
The second-oldest mammoth lived as along as 1. 34 million years ago and belonged to a population that were the ancestors of the woolly mammoth, the last mammoth to go extinct about 5,000 years ago.
They compared its genome with a woolly mammoth that lived about 700,000 years ago and some that lived not long before they disappeared.
The youngest specimen they found and sequenced was from a tooth of an early form of woolly mammoth that lived more than 680,000 years ago.
While the permafrost had helped to preserve the DNA, it was still very challenging to extract from the samples, the researchers said.
Being able to extract and analyze million-year-old DNA could allow scientists to track the origins and evolution of many different species, including potentially our own.
In theory, the researchers said it is possible to extract DNA from specimens that are 2. 6 million years old.
That's the age of the earliest permafrost -- soil that remains frozen all year long and helps stop the DNA from degrading.
It is unlikely that ancient DNA could be preserved so well outside permafrost regions, they said.