The Oldest DNA Ever Discovered by Scientists Could Explain How Humans Evolved
It’s believed to be two million years old.
Scientists have discovered the oldest DNA yet, and it may hold clues to how modern humans evolved. Researchers from the University of Copenhagen extracted the genetic material from permafrost in one of the planet's northernmost points. It's nearly twice as old as the oldest previously found sample. Experts say the new information has a wealth of implications for how we understand human history. "I think it's going to blow people's minds," geoscientist Andrew Christ told the New York Times. "It certainly did so for me." Read on to find out why scientists are so excited.
The newly discovered DNA was found in Greenland and is believed to be two million years old—nearly twice as old as the one-million-years-old wooly mammoth DNA that previously held the record. Scientists found genetic fragments from 135 species, including reindeer, rabbits, lemmings, birch and poplar trees, and the long-extinct giant mastodon. The genetic material was found in sediment at the mouth of a fjord near the Arctic Ocean in northern Greenland. The DNA had survived in clay and quartz deposits within a geological formation known as Kap Kobenhavn.
Researchers at the University of Greenland developed new ways of extracting DNA from ancient samples found in nature. That allowed them to discover millions of genetic fragments in samples from the site. They found 102 different kinds of plants, including 24 new ones, and a variety of land animals and marine creatures, such as horseshoe crabs, corals, and algae. The researchers are now trying to determine how all these species survived in the Arctic Circle—for example, trees thrived there, although they lived half the year in complete darkness.
Some of their early findings: Mastodons lived further north than previously believed, and caribou—previously thought to be a million years old, going by the fossil record—are now known to be twice as old. The presence of crabs meant the ocean was once much warmer than it is now. The age and evolution of these animals have implications for the history of humans. It may now be possible to find and analyze the earliest human DNA, learning more about how humans evolved, or discovering lost species.
"DNA can degrade quickly, but we've shown that under the right circumstances, we can now go back further in time than anyone could have dared imagine," said Eske Willerslev of the University of Copehagen. "The ancient DNA samples were found buried deep in sediment that had built up over 20,000 years. The sediment was eventually preserved in ice or permafrost and, crucially, not disturbed by humans for two million years. He added: "A new chapter spanning one million extra years of history has finally been opened, and for the first time, we can look directly at the DNA of a past ecosystem that far back in time."
Scientists say the ancient data could be key to human survival in the future. "It is possible that genetic engineering could mimic the strategy developed by plants and trees two million years ago to survive in a climate characterized by rising temperatures and prevent the extinction of some species, plants and trees," said Kurt Kjær of the University of Copenhagen. "This is one of the reasons this scientific advance is so significant because it could reveal how to attempt to counteract the devastating impact of global warming," he added.