DNA fragments recovered from the northern Greenland ice sheet are the oldest pieces of DNA ever discovered, a group of Danish scientists reported on December 7, 2022. nature. The researchers dated the sample to about 2.4 million years ago, and the DNA sequence was dated to about 2.4 million years ago. Formerly the oldest DNArecovered from the bones of a Siberian mammoth.
“This is a great performance. It’s just amazing,” said Ross McPhee, a paleontologist at the American Museum of Natural History who was not involved in the study. science.
Researchers prepare sediment cores for sampling in Copenhagen
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Study co-author Karina Sand, a geochemist at the Lundbeck Foundation Center for Geogenetics at the University of Copenhagen, said the DNA was preserved due to a combination of the site’s soil composition and the rapid temperatures during the Ice Age, which began about 2.5 million years ago. spoke. science. The secret to obtaining sequences from such old samples is a revised extraction protocol, which allows the research team to pry ancient DNA from the quartz and clay in the sediments, the media reported. explained.
Ancient DNA fragments found in the ice sheet were from more than 135 different species. new york times. DNA fragments collected from the environment are known as environmental DNA or eDNA, and are often used to monitor the presence and abundance of species in modern ecosystems. Scientists in Denmark did the same with ancient fragments, analyzing their DNA to determine which species were present in the ecosystem 2.4 million years ago.
Researchers found DNA from traditional Arctic inhabitants such as reindeer, lemmings and arctic hares. But to their surprise, they also discovered living species that no longer exist in Greenland, as well as extinct species not normally associated with the region. The modern species detected included poplars, birch trees, and horseshoe crabs, but none of them live that far north. “No one would have predicted an ecosystem like this,” said Eske Willerslev, a paleogeneticist at the University of Cambridge who led the study. science. “Today, it is an ecosystem without analog.”
One of the most surprising discoveries was the discovery of DNA from an undocumented mastodon lineage, said Rav Dalen, a paleogeneticist at Stockholm University who was not involved in the study. times. He previously said the mastodon DNA found closest to the Greenland site, located further south in Canada, is much younger, at just 75,000 years old.
See Mastodon on the Move
Beth Shapiro, a paleogeneticist at the University of California, Santa Cruz, who was not involved in the study, said: “The ability to infer such a complete picture of ancient ecosystems from tiny pieces of preserved DNA is a huge challenge. It’s almost like magic.” times.
This discovery further confirms the value of eDNA and the vast potential of ancient DNA to unlock new insights into the prehistoric world, Willerslev said. science. McPhee agreed, telling the magazine, “It’s possible to see a future where everything we currently call paleontology is done in molecular biology labs.”
FAQ
What is ancient DNA?
- ancient dna DNA from ancient sources such as biological specimens and environmental DNA. because DNA breaks down Over time, ancient DNA often becomes of lower quality than modern DNA, limiting the analyzes researchers can perform. However, modern nucleic acid analysis methods can help overcome some of these obstacles.
What is environmental DNA?
- environmental dna Alternatively, eDNA can be obtained from various environmental sources such as soil, water, snow, and air. This DNA is shed into the environment after being shed from the hair, skin, and feces of living organisms. Analyzing modern or ancient environmental DNA provides information about an ecosystem’s biodiversity.
What is the oldest piece of DNA ever discovered?
- In 2022, researchers analyzed ancient environmental DNA Originally from Greenland. Scientists dated the sample to about 2.4 million years ago. Researchers sequenced the samples and found DNA from more than 135 species, including reindeer, arctic hares, birch trees, and extinct species.
How long does DNA last?
- Researchers believe that DNA has half life 521 years. However, different environmental conditions can speed up or slow down DNA degradation. In the case of Greenland’s ancient DNA, icy temperatures and soil conditions may have contributed to its preservation.
This article was originally published on December 7, 2022. Updated on September 23, 2024. Niki SpahicPh.D.
