Fossils tell us a lot about extinct animals from millions of years ago, but DNA sequencing can tell us a lot more, especially when the fossils they come from are only tiny fragments of the original animal. But DNA begins to degrade as soon as a creature dies. For example, there is no readable DNA from dinosaurs, despite what Jurassic Park would have you believe. But a discovery of some teeth from steppe mammoths (an elephant that preceded the woolly mammoth) is setting records for readable DNA.
The clues come from some incredibly old DNA extracted from a trio of molars uncovered in northeastern Siberia. The oldest is nicknamed the Krestovka mammoth, dated to about 1.2 million years ago. The other two molars are nicknamed the Adycha and Chukochya mammoths, dated to 1 million and 500,000 to 800,000 years old, respectively. The fact that the researchers were able to extract and analyze the DNA from these fossils at all is a landmark. Up until now, the oldest look at ancient genes came from an Ice Age horse that lived over 560,000 years ago. The new mammoth samples double that, taking the title for the oldest DNA yet recovered from fossil remains. "We had to deal with DNA that was significantly more degraded compared to the horse," says Swedish Museum of Natural History paleogeneticist Love Dalén, an author of the new study.
At any rate, the extracted DNA from the step mammoths revealed some surprising findings, such as their long hair (which makes the illustration above obsolete) and their relationship to other mammoths. Read about the mammoth findings and the feat of extracting million-year-old DNA at Smithsonian.