The oldest DNA ever recovered from an animal is adding new chapters to mammoth life history, going back more than 1 million years.
Genetic material from ancient mammoth molars found in Siberia handily beats the previous record set by 700,000-year-old DNA from a frozen, fossilized horse (SN: 6/26/13). Some mammoth gene snippets suggest that ancient mammoths already had the traits that allowed them to withstand cold temperatures during later ice ages. What’s more, some hairy behemoths that inhabited North America may have been a hybrid mix between the woolly mammoth and a previously unknown mammoth species, researchers report February 17 in Nature.
The findings “really highlight the exciting times that we live in,” says Charlotte Lindqvist, an evolutionary biologist at the University at Buffalo in New York who was not involved in the work. “We can get genetic data — we can recover DNA — from such ancient samples that can directly give us windows into the past.” Such data can reveal how extinct animals evolved, adding to the clues that come from physically examining ancient bones.
The mammoth DNA was extracted from three molars unearthed in the 1970s from permafrost in northeast Siberia. Though DNA degrades into shorter strings of genetic material over time, making it difficult to handle and piece together, cold permafrost helps to protect genetic information from rapidly falling apart. Theoretical studies had suggested that researchers could perhaps recover DNA that is more than 1 million years old. Still, the recovered DNA is “quite close to the limit of what is possible,” says Love Dalén, an evolutionary geneticist at the Centre for Palaeogenetics in Stockholm.