Extinct cave bears (Ursus spelaeus complex) from the Ice Age (spanning 2.6 million to 11,700 years ago) have a genetic presence in extant brown bears (Ursus arctos), suggesting the two likely interbred. The findings were published yesterday (August 27) in Nature Ecology & Evolution.
On comparing the genomes of brown bears and cave bears that lived between 71,000 and 34,000 years ago, researchers found the former contains between 0.9 percent and 2.4 percent of cave bear DNA. The cave bear remnant also has brown bear DNA, but to a lesser extent.
A. Barlow et al., “Partial genomic survival of cave bears in living brown bears,” Nat Ecol Evol, doi:10.1038/s41559-018-0654-8, 2018.