dFragments of NA recovered from the ice sheet in northern Greenland represent the oldest DNA ever discovered, a group of Danish scientists reported on December 7, 2022. nature. The research team estimated the age of the sample to be about 2.4 million years ago and made the DNA sequence approximately twice that old. Previously Oldest DNAFound in Siberian mammoth bones.
“This is a tour de force. “It’s truly amazing.” Ross MacPhee, a paleontologist at the American Museum of Natural History who was not involved in the work, said: science.
A researcher prepares sediment cores for sampling in Copenhagen.
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Karina Sand, a geochemist at the Lundbeck Foundation Center for Geogenetics at the University of Copenhagen and co-author of the study, said a combination of the region’s soil composition and plummeting ice age temperatures that began about 2.5 million years ago preserved the DNA. science. The secret to obtaining sequences from such old samples, the outlet explained, was a modified extraction protocol. This allowed the team to pull out ancient DNA from the quartz and clay in the sediments.
Ancient DNA fragments discovered in the ice sheet are said to come 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. Danish scientists did the same using ancient carvings. That means analyzing DNA to determine what species were present in the 2.4 million-year-old ecosystem.
Researchers have discovered DNA from traditional Arctic inhabitants such as reindeer, lemmings and Arctic hares. But surprisingly, they also found modern species that no longer exist in Greenland, as well as extinct species not typically associated with the region. Among the modern species discovered were poplar, birch, and horseshoe crabs, none of which still live in the north. “No one would have predicted an ecosystem like this,” said Eske Willerslev, a paleontologist at the University of Cambridge who led the study. science. “It’s an ecosystem that has no analogue at the moment.”
One of the most surprising discoveries was the discovery of DNA from an undocumented mastodon branch, said Love Dalén, a paleontologist at Stockholm University who was not involved in the study. times. The mastodon DNA previously found closest to the Greenland site was from much further south in Canada and was much younger, at least 75,000 years ago, he said.
See ‘Mastodon on the move’.
“It feels almost magical to be able to infer a complete picture of an ancient ecosystem from a small piece of preserved DNA,” said Beth Shapiro, a paleontologist at the University of California, Santa Cruz, who was not involved in the study. times.
The discovery further confirms the value of eDNA and the vast potential of ancient DNA to open new insights into the prehistoric world, Willerslev said. science. MacPhee agrees, telling the magazine that it is now “possible to see a future in which everything we now call paleontology takes place in molecular biology laboratories.”
FAQ
What is ancient DNA?
- ancient DNA DNA collected from ancient sources, such as organic specimens or environmental DNA. because DNA is broken down Over time, ancient DNA typically becomes lower quality than modern DNA, often limiting the analyzes researchers can perform. However, modern nucleic acid analysis methods help overcome some of these obstacles.
What is environmental DNA?
- environmental DNA Alternatively, eDNA comes from a variety of environmental sources, including soil, water, snow, and air. This DNA eventually remains in the environment after being shed from the organism’s hair, skin, and feces. Analyzing modern or ancient environmental DNA can provide information about the biodiversity of an ecosystem.
What is the oldest DNA ever discovered?
- In 2022, the researchers analyzed. ancient environmental DNA From Greenland. Scientists dated the sample to about 2.4 million years ago. After sequencing the samples, the researchers found DNA from more than 135 different species, including reindeer, arctic hares, birches and extinct species.
How long does DNA last?
- Researchers have determined that DNA has the following characteristics: half life 521; However, different environmental conditions can speed up or slow down DNA degradation. In the case of ancient DNA from Greenland, ice-cold temperatures and soil conditions likely contributed to its preservation.
This article was originally published on December 7, 2022. Updated on September 23, 2024. Nikki Spahichdoctor.
