/kloc-mammoth portrait 0/100,000 years ago.
This research result was published in the famous British magazine Nature on February 17. Researchers extracted DNA from mammoth teeth buried in Siberian permafrost and analyzed the genomes of three ancient mammoths. One of the genomes can be traced back to 654.38+6500 years ago.
According to this study, the grassland mammoth specimen from which DNA was extracted was separated from other Siberian mammoths and was the ancestor of the more widely known woolly mammoth.
Love Dalén, the lead author of this study and a professor of evolutionary genetics at the Stockholm Paleogenetics Center, said: "This DNA is very old. These samples are older than Viking remains 1000 times, even before the existence of humans and Neanderthals. "
The researchers took away the tooth of a mammoth.
The oldest DNA measured before can be traced back to a horse leg bone in Canada from 780 thousand to 560 thousand years ago.
Scientists say that extracting DNA from mammoth specimens is "challenging" because there is only a very small amount of DNA left in the sample and the DNA is degraded into very small fragments.
These mammoth specimens were first discovered in the 1970s, and since then, they have been kept in the Russian Academy of Sciences in Moscow.
In fact, mammoths were not woolly mammoths at first, and there were no woolly mammoths about 1 ten thousand years ago. Ancient grassland mammoths are the predecessors of woolly mammoths. Scientists believe that they came from a species in Europe, earlier than woolly mammoths and Colombian mammoths. Columbia mammoth is a species in North America.
Tooth specimens of mammoths in ancient grasslands
Scientists say that DNA helps to clarify the genetic history of mammoths and how they migrated and evolved around the world. In addition, this study also provides a new insight into the time and speed for mammoths to adapt to cold climate.
The researchers said that the new results also opened the door for future research on other species. According to this study, about 654.38 billion years ago, many animal species expanded on a global scale. This is a period of great changes in climate and sea level, and it is also the last transposition of the earth's magnetic poles.
Because of this, researchers believe that this time-scale gene sequencing analysis has great potential in exploring a wide range of scientific problems.
Anders g? Head of joint research and professor of molecular archaeology at Stockholm Paleogenetics Center? Thurstel? M) said, "The biggest question now is how far back we can go."
"We haven't reached the limit yet," Goethstrom said. "An educated guess is that we can recover the DNA 2 million years ago, and maybe even go back to 2.6 million years ago, which is the limit of permafrost. The climate was too warm before that. "
The age of mammoth specimens is determined by geological data and molecular clock. Molecular clock is a technique to predict how evolution will happen according to the estimated mutation rate of genes.