Settling a heated debate in a reasonable manner

Dear Library Answer Person,

I have two friends who are currently embroiled in a heated debate about the phylogeny of bears. One friend asserts that polar bears and grizzly bears share a common ancestor. The other maintains that polar bears are descendants of the grizzly bear. Despite numerous attempts to find a conclusive answer, they have yet to settle the conflict. I was wondering if you could lend your expertise.

Thank you,

The Mediator

Really?! You have two friends who are “embroiled in a heated debate about the phylogeny of bears.”  I’m not buying it.  And if it’s true, good gracious (!), you need to get some new friends.  My solution: let your two friends go at each other and find out which is the grizzly and which is the salmon.