Scientists sequenced DNA from the teeth of mammoths discovered in the 1970s in the East Siberian permafrost. The preserved teeth are said to be up to 1.6 million years old and probably belong to a new species of mammoth. This was reported by the journal Nature in a published study on February 17, 2021.
The researchers said the three tooth samples, one about 800,000 years old and two well over a million years old, provided important insights into giant Ice Age mammals, including ancient heritage, particularly the woolly mammoth.
The genomes surpass the oldest DNA previously sequenced, that of a horse from 560,000 to 780,000 years ago.
The mammoths were originally discovered in Siberia in the 1970s and preserved at the Russian Academy of Sciences in Moscow. However, new scientific methods were needed to extract the DNA.
The team also extracted genetic data from tiny powder samples of each mammoth tooth, “Essentially like a pinch of salt you would put on your plate,” Love Dalén, a professor of evolutionary genetics at the Centre for Paleogenetics in Stockholm and lead author of the study, explained at a press conference.
While the material had broken down into very small fragments, scientists were able to sequence tens of millions of chemical base pairs that make up the DNA strands and establish age estimates based on the genetic information.
This indicated that the oldest of the three mammoths discovered near the namesake Krestovka River was even older than originally thought, at about 1.65 million years old, while the second, called Adycha, was about 1.34 million years old. The youngest, Chukochya, is about 870,000 years old and is one of the earliest woolly mammoths found to date.
Research on the Krestovka mammoth showed that this particular species of mammoth diverged from other Siberian mammoths more than two million years ago. “This was a complete surprise to us. All previous studies have shown that there was only one species of mammoth in Siberia at that time, the steppe mammoth,” said study co-author Tom van der Valk of the Swedish Natural History Museum. Meanwhile, the study found that the older Krestovka mammoth represents a previously unrecognized genetic lineage that researchers estimate diverged from other mammoths about two million years ago and was ancestral to those that colonized North America 1.5 million years ago.
Heiner Kubny, PolarJournal
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