Thing is when it comes to things like that there arn't definite answers. Now it has nothing to do with believers because the topic doesn't affect their faith one way or the other (generally) so they don't concern themselves with it. But when talking with an unbeliever it becomes problematic because that's when it starts to really matter(atleast in terms of guiding an unbeliever to Christ). There are no definite answers to the race question. (as far as I know. But there could be some excellent studies and theories on the subject) But really the way we show people the Lord aren't solely in isolated facts. They are necessary yes, the word says at to your faith knowledge, but if the knowledge isn't prestented with grace, honesty, love and patience (what makes us Christ followers!!) then it's vain. No matter how true an answer might be, if not presented properly then its useless to the other person. So I think it's always important to be honest and genuine. It will speak volumes more then random facts can. (combine the both though, and you'd be pushing Jedi master status lol) So add to your faith knowledge like the word says but remember that the genuiness OF your faith is more important, and needs to be the foundation.
If I were you I'd just honestly tell them I don't know the answer. Don't get deffensive, offended, or have your faith shaken. Stand your ground, be gracious, and keep the conversation going. There already talking to you so want some truth, so just keep the convo and the Lord will direct your path.
