Did polar and brown bears warm-up to one another?
Maybe we’re seeing a hint that in really warm times, polar bears changed their lifestyle and came into contact, and indeed interbred, with brown bears.
Professor, Biochemistry and Molecular Biology, Penn State, USA
Research Scientist, Nanyang Technological University, Singapore
Image: Hybrid bear : taken from - http://www.flickr.com/photos/derstefan/7303775984/Author: Der Stefan http://creativecommons.org/licenses/by-sa/2.0/deed.en