Genetic variety rising, possibly with help from stray Russian bears
Once near extinction, Finland’s brown bears are defying expectations in how quickly they are regaining the genetic underpinnings of a healthy population.
In just a generation and a half, the nation’s southern bears have reached a level of genetic diversity and population mixing that theorists predict would typically take 10 generations or more, researchers say April 22 in Proceedings of the Royal Society B.
From 1996 through 2010, the once rather isolated southern bear group expanded its range north about 7.4 kilometers per year on average. That spread allowed them to mix more with high-latitude brown bears. In southern Finland, the brown bears also now mingle freely with a growing number of Russian counterparts adventuring over the border. These encounters very likely helped fuel a surge in genetic diversity among the southern Finnish bears, says study coauthor Snorre Hagen of the Norwegian