When Love Dalén first began studying ancient DNA as a Ph.D. student back in 2002, one of his colleagues suggested working on lemmings, the tiny arctic rodents and '90s video game icons. "Everyone is doing mammoths," she told Dalén, "it's very competitive." The hulking, ancient proboscideans have captured the imagination of the public and scientists for years -- and when an opportunity arose for Dalén to study the famous woolly mammoth, he couldn't resist. He wanted to understand why the creatures went extinct.
But on Wednesday, Dalén and 21 other scientists looked at the other end of the woolly mammoth's timeline: its origin. In a history-making paper, published in the journal Nature, the team announce their retrieval of DNA from mammoth specimens over a million years old -- demolishing the record for the oldest ancient DNA ever sequenced by almost 900,000 years.
"It's an amazing paper," says Sally Wasef, an ancient DNA researcher at Griffith University in Australia. She isn't affiliated with the research.
The breakthroughs are twofold. First, the team was able to isolate short, degraded DNA fragments from teeth samples and obtain the genetic code via recent improvements in sequencing and data analysis techniques.
To sequence the ancient DNA, the team examined mammoth molars from three different mammoths unearthed in the Siberian permafrost a few decades ago. "We knew that some of these teeth were from the earliest woolly mammoths," says Dalén. He says the team "got small pieces of the roots from these teeth," which usually weigh a few kilograms, from their collaborators in Russia for study. For a megaannum, the molars were protected from degradation thanks to the freezing cold temperatures present at Siberia's high latitudes.
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The DNA sequence also led to the second breakthrough: The team was able to assess mammoth evolution and speciation over a million years ago using the three samples. Krestovka's data pointed to an entirely new lineage of mammoth, previously unknown to science. This was something of a surprise for the team.
...
Both breakthroughs will contribute to furthering paleogenomics, the study of ancient DNA from extinct species.
Source: https://www.cnet.com/news/1-6-million-year-old-mammoth-dna-uncovers-lineage-we-never-knew-existed/
But on Wednesday, Dalén and 21 other scientists looked at the other end of the woolly mammoth's timeline: its origin. In a history-making paper, published in the journal Nature, the team announce their retrieval of DNA from mammoth specimens over a million years old -- demolishing the record for the oldest ancient DNA ever sequenced by almost 900,000 years.
"It's an amazing paper," says Sally Wasef, an ancient DNA researcher at Griffith University in Australia. She isn't affiliated with the research.
The breakthroughs are twofold. First, the team was able to isolate short, degraded DNA fragments from teeth samples and obtain the genetic code via recent improvements in sequencing and data analysis techniques.
To sequence the ancient DNA, the team examined mammoth molars from three different mammoths unearthed in the Siberian permafrost a few decades ago. "We knew that some of these teeth were from the earliest woolly mammoths," says Dalén. He says the team "got small pieces of the roots from these teeth," which usually weigh a few kilograms, from their collaborators in Russia for study. For a megaannum, the molars were protected from degradation thanks to the freezing cold temperatures present at Siberia's high latitudes.
...
The DNA sequence also led to the second breakthrough: The team was able to assess mammoth evolution and speciation over a million years ago using the three samples. Krestovka's data pointed to an entirely new lineage of mammoth, previously unknown to science. This was something of a surprise for the team.
...
Both breakthroughs will contribute to furthering paleogenomics, the study of ancient DNA from extinct species.
Source: https://www.cnet.com/news/1-6-million-year-old-mammoth-dna-uncovers-lineage-we-never-knew-existed/
