Extinct cave bear DNA lives on in modern brown bears

Extinct cave bear DNA is present in living brown bears, a new study reveals, shedding light on a hybridization that happened during the late Pleistocene era. The last cave bears died out about 25,000 years ago likely due to a combination of both human activity and natural climate change. Thanks to new research, though, we know that around 0.9- and 2.4-percent of modern brown bear DNA can be traced back to these extinct creatures.

The study utilized DNA recovered from the remains of four cave bears dating back approximately 35,000 years, as well as the DNA of existing polar and brown bears. The two latter creatures, as expected, showed far more relation to each other than to the extinct cave bears.

However, a further look into the data revealed instances of brown bear and cave bear DNA mirroring each other, indicating that the two species were interbreeding thousands of years ago. Speculation of such hybridization has been around for a while, but the new study confirms it.

The study states:

Our results show that even though extinction is typically considered as absolute, following admixture, fragments of the gene pool of extinct species can survive for tens of thousands of years in the genomes of extant recipient species.

A similar reality was previously found concerning humans and Neanderthals, the latter of which contributed to modern humans' genetic makeup. A study published last year found that 1.8- to 2.6-percent of Neanderthal genes persist in individuals of Eurasian ancestry.

SOURCE: Nature