I have a good friend who I met a couple years ago in the same forum where I met my twin. He's a physicist who is pro-evolution, but he has the best attitude about these debate issues. Though he is quite firm about his stance on common descent, he doesn't talk down to me, is respectful, and listens as well as provides the opposing viewpoint without getting nasty about it.
It's really too bad that there aren't more scientists like him out there, because if there were, all this intense bickering would be non-existent. He's also got a heck of a sense of humor, which is always helpful when discussing these issues that tend to fire people up fairly easily.
Anyway, I always refer to him as monkey boy because somewhere he picked up this crazy idea that he's a distant relative to those tree swingers.
Check out the card he sent me for my birthday.