Sometimes I suspect that wouldn't even occur to them as a question. That evolution might turn out to be one of those things that it's just assumed any race that had mastered agriculture MUST understand.
Because, well, how could a race use selective breeding, and NOT realise that evolution by natural selection occurs?
The British agricultural revolution involved animal breeding starting in about 1750. Darwin didn't publish Origin of Species until 1859, so in reality it took about 100 years for the other shoe to drop.
Here's the new thread for posting quotes, with the usual rules: