I did not know that "invariably" meant they ALWAYS do it... ugh.

I had the exact same interpretation of the premise. "Since those days" means up until yesterday in my mind. I see a timeline of: [thousands of years ago]->[Since thousands of years ago up until yesterday]->[today]. If I had to stretch my understanding, the author didn't conclude that "most wild large mammal species since those days would either be difficult or not worth it". The author says today. And if today, specifically, it is much easier to domesticate them than all previous days, the conclusion the author stated would not hold. This is a stretch of my imagination but I thought I'd share just in case.

@ChristianSandlin taking the test at all is ambitious, not everyone’s available study time is created equal

@JaidaAnderson be proud of yourself for taking the step. Some never get this far and only dream.