Polar bears evolved from brown bears less than 500,000 years ago. That's why they can still interbreed and produce pizzlies!

Why have I never heard of pizzlies before? Do I need to make this a factoid?

I had never heard of pizzlies until now!  

First reaction:  Pizzlies and other hybrids signify end of times.

http://news.nationalgeographic.com/news/2010/12/photogalleries/101215-pizzly-grolar-bear-polar-grizzly-hybrids-nature-arctic-global-warming-pictures/

Not the end of times, but the BEGINNING of new times.

Perhaps these are the critters who can survive climate change!