An international team led by researchers from the Stockholm Center for Paleogenetics has conducted a sequence DNA: recovered from the remains of mammoths, which reach the age of 1.2 million. Analyzes show that the Colombian mammoth, which settled in the last glacial period in North America, was a hybrid of the woolly mammoth, a genetic lineage of the previously unknown mammoth. In addition, the study provides a new insight into how fast mammoths have adapted to cold climates. These results were published today (February 17, 2021) Nature:,
About a million years ago, there were no woolly or Colombian mammoths because they had not yet developed. This was the time of their predecessor, the ancient steppe mammoth. Researchers have now been able to analyze the genomes of three ancient mammoths using DNA recovered from mammoth teeth buried in 0.7-1.2 million years in Siberian permanent ice.
This is the first time that DNA has been sequenced, confirmed by millions of samples, from which DNA extraction has been difficult. The researchers found that there was only one minute of DNA left in the samples, that the DNA had broken down into very small fragments.
“This DNA is incredibly old. “The specimens are a thousand times older than the Viking remains, even earlier than the Neanderthals,” said Love Dalén, a senior author and professor of evolutionary genetics at the Stockholm Center for Paleogenetics.
The age of the samples was determined using both geological data and a molecular clock. These two types of analyzes showed that two of the specimens were more than one million years old, while the third was about 700,000 years old and represented one of the earliest woolly mammoths.
The unexpected origin of the Colombian mammoth
Genome analysis showed that the oldest specimen, which was about 1.2 million years old, belonged to a previously unknown genetic lineage of the mammoth. Researchers call this the Krestovka mammoth, based on the location where it was found. The results show that Krestovka mammoth deviated from other Siberian mammoths more than two million years ago.
“It simply came to our notice then. All previous studies have shown that there was only one species of mammoth in Siberia at that time – the steppe mammoth. But our DNA analysis now shows that there were two different genetic lineages, which we call here Adicha mammoth և Krestovka mammoth. We can not say for sure, but we think they can represent two different types, “said lead author Tom van der Valk.
Researchers believe that the mammoths belonged to the Krestovka dynasty, which colonized North America about 1.5 million years ago. In addition, the analysis shows that the Colombian mammoth, which settled in the last glacial region of North America, was a hybrid. About half of its genome came from the Krestovka clan and the other half from a woolly mammoth.
“It simply came to our notice then. “It turns out that the Colombian mammoth, one of the most remarkable species of the North American ice age, evolved through hybridization that took place about 420,000 years ago,” said co-author Patrícia Pečnerová.
Evolution և adaptation in wool mammoth
The second million-year-old genome of the Adicha mammoth seems to have been the ancestor of the woolly mammoth. Therefore, researchers can compare its genome with the genome of one of the earliest woolly mammoths that lived 0.7 million years ago, as well as with the mammoth genomes, which are only a few thousand years old. This allowed us to explore how mammoths adapted to life in cold climates and how well those adaptations developed during the spawning season.
Analyzes have shown that genetic variants of life in the Arctic, such as hair growth, heat regulation, fat accumulation, cold tolerance, and circadian rhythms, already existed in millions of mammoths long before the origin of woolly mammoths. These results show that most of the mammoth adaptations occurred slowly over time.
“Being able to reverse genetic changes throughout a special event is unique. “Our analysis shows that most of the cold adaptations were already present in the ancestors of the woolly mammoth.”
The new results open the door to a wide range of further studies on other species. About a million years ago, there was a time when many species spread across the globe. This was a time of great change in climate and sea level, as it was the last time the Earth’s magnetic poles shifted. Because of this, researchers believe that genetic analysis at this time scale has great potential for exploring a wide range of scientific issues.
“One of the big questions now is how far we can go in the past. We have not reached the border yet. It would be an educated prediction that we could recover DNA that is two million years old, և, possibly even 2.6 million. “Before that, there was no perpetual frostbite where old DNA could be stored,” said Anders Goeterstream, a professor of molecular archeology at the Center for Paleogenetics and head of joint research.
Reference. February 17, 2021 Nature:,
DOI: 10.1038 / s41586-021-03224-9:
The study is the result of an international collaboration involving 22 scientists from nine countries. In addition to researchers from the Center for Paleogenetics, a joint research center funded by Stockholm University and the Swedish Museum of Natural History, the study also includes researchers from the Russian Academy of Sciences, the Museum of Natural History and the Creek Institute in the United Kingdom. , Santa Cruz UC, University of Potsdam, Germany, Agricultural University of China, Middle East Technical University of Turkey, Arctic University of Norway, University of Copenhagen, Denmark.