Cave bears were giant plant eating bears that roamed Europe and northern Asia, and went extinct around 25 thousand years ago. They hibernated in caves during the winter. This was a dangerous time, as those which had failed to fatten up enough during the summer would not survive hibernation.

As a result, many caves across Europe and northern Asia are now filled with the bones of cave bears, each one containing potentially thousands of individuals. In our new study, we analysed a bone from a cave in the Caucasus Mountains.

Our team recovered the genome from a 360,000-year-old cave bear, revealing new details of the animals' evolutionary history and almost rewriting their entire evolutionary tree. As well as what it can tell us about cave bear evolution, this discovery is a breakthrough for the field of ancient DNA.

February 2021 was an important month for the study of palaeogenomes – the analysis of genomes from extinct species. Two studies were published just one day apart, one reporting the oldest genome from a permafrost environment – from a 1.2 million year old mammoth tooth – and our new research, reporting the oldest genome from a non-permafrost environment.

Non-permafrost genomes

After death, the environment in which an animal dies in strongly affects the speed at which its tissues degrade. We see this every day in our kitchens – food left out on a hot day quickly spoils, but the same food stored in the freezer can last for months. DNA is no different, it survives a long time in the near perfect conditions of permafrost. But the warmer the storage conditions, like in non-permafrost environments, the faster DNA will degrade to a state where it's no longer recognisable as the original product.

Even if the DNA has survived all that time, a major challenge for palaeogenome recovery is ancient samples are also usually highly contaminated with microbial DNA from the external environment – like the bacteria that fed on the decaying corpse or live in the surrounding soil. These typically outnumber the sample DNA, which increases the cost of genome sequencing by up to a factor of 100. This make most palaeogenome sequencing of ancient samples simply too expensive to undertake.

France's former president Nicolas Sarkozy said Tuesday that he might consider taking his appeal against a corruption conviction to the European Court of Human Rights.

"I can't accept being convicted for something I didn't do," Sarkozy told the French daily Le Figaro a day after he was found guilty of corruption and handed a three-year prison sentence.

Rep. Marjorie Taylor Greene (R-GA) on Tuesday said gun safety measures taken by Congress are the "real voter suppression."

During a House floor debate on election integrity, Greene spoke up to object to the bill sponsored by Democrats.