April 29, 2024

2.4 Million-Year-Old DNA Is Oldest Ever Recovered

DNA pieces recovered from an ice sheet in northern Greenland represent the earliest DNA ever found, a group of Danish researchers report today (December 7) in Nature. The team dates the samples to around 2.4 million years back, making the DNA sequenced almost twice the age of the previously oldest DNA, which was recovered from a Siberian mammoth bone.” Its a trip de force. Just astonishing,” Ross MacPhee, a paleontologist at the American Museum of Natural History who was not included with the work, informs Science.A scientist prepares a sediment core for sampling in CopenhagenCOURTESY OF NOVA, HHMI TANGLED BANK STUDIOS & & HANDFUL OF FILMSA mix of the websites soil structure and the plunging ice-age temperature levels that started around 2.5 million years ago preserved the DNA, research study coauthor Karina Sand, a geochemist at the Lundbeck Foundation GeoGenetics Centre at the University of Copenhagen, informs Science. The technique to obtaining sequences from such old samples were modified extraction protocols, the outlet discusses, which allowed the group to pry ancient DNA from the quartz and clay in the sediment.The pieces of ancient DNA found in the ice sheet originated from more than 135 different types, according to The New York Times. DNA pieces gathered from the environment are understood as environmental DNA, or eDNA, and are often utilized to keep an eye on species existence and abundance in modern environments. The Danish researchers used the ancient pieces to do the same thing, analyzing the DNA in order to figure out which species remained in the 2.4 million-year-old ecosystem.See “Warming Climate Hurt Megafauna?” The researchers found DNA from standard Arctic residents such as reindeer, lemmings, and Arctic hares. To their surprise, they likewise found modern-day species that no longer exist in Greenland and extinct species that wouldnt normally be associated with the area. Among the contemporary types discovered were poplar and birch trees in addition to horseshoe crabs, none of which still live that far north. “No one would have anticipated a community like this,” Eske Willerslev, a paleogeneticist at the University of Cambridge who led the research study, tells Science. “Its an environment with no analog in the present day.” One of the most unexpected findings is the discovery of DNA of an undocumented branch of mastodons, Love Dalén, a paleogeneticist from Stockholm University who wasnt involved with the research study, tells the Times. Previously, he states, the mastodon DNA discovered closest to the Greenland site lay much even more south in Canada and was much more youthful at only 75,000 years old.See “Mastodons on the Move”” It feels almost magical to be able to presume such a complete image of an ancient environment from small fragments of preserved DNA,” Beth Shapiro, a paleogeneticist at the University of California, Santa Cruz who wasnt included with the research, tells the Times.The findings are additional confirmation of the worth of eDNA and the vast capacity of ancient DNA to unlock new insights into the prehistoric world, Willerslev tells Science. MacPhee concurs, telling the publication that its now “possible to see a future in which what we now call paleontology all takes place in a molecular biology lab.”