Rather than just shutting down topics that would normally get thrown away, there could be a Questions and Answers forum where people could ask questions and learn about things without necessarily debating.
I agree with Gary. We could have two forums to handle many new topic starters.
1) Questions and answers about Evolution.
2) Questions and answers about Faith and Belief.
When a sketchy proposed new topic comes along, throw it in as a question to one of these two forums. That way, we have less clutter.