About hybrid bears, and the possible re-occurrence of similar happening over time, can show how there are several kinds of bears and the fact they can interbreed to create fertile offspring show they do in fact share a history and a fair amount of DNA.

{re: AKexpat}

Some credible findings from a simple search; among other results, appear here:

https://duckduckgo.com/?q=history+of+bear+hybrid+polar+grizzly+in+DNA&t=ffsb&ia=web

For those who haven't had scientific interests as a lifelong hobby, the learning curve can be steep. ;)