Javier Trueba/Madrid Scientific Firlms/Science Source

ScienceShot: Earliest Unfrozen Ancient DNA Reveals Some Bear Facts

Scientists have recovered DNA from a cave bear fossil at least 300,000 years old. Reported online this week in the Proceedings of the National Academy of Sciences, the finding bests the previous record for DNA recovered from a sample found outside of the artic permafrost—that from a 120,000-year-old polar bear jawbone from Norway published in 2010. (Researchers have sequenced DNA of plants and invertebrates up to 800,000 years old frozen in Arctic ice.) The new specimen comes from a cave in northern Spain called Sima de los Huesos, where nearly 30 prehistoric human skeletons have been found, and the DNA comes from mitochondria, small bodies within cells that generate energy and have their own DNA. A comparison of DNA sequences suggests the bear, Ursus deningeri (above), was a direct ancestor or close relative of the ancestor of later cave bears, such as Ursus spelaeus, which died out about 28,000 years ago. New techniques used in the work might also allow the researchers to sequence DNA from the prehistoric humans found in the cave.

See more ScienceShots.