system
Given the following post, respond as if you're commenting on Reddit:
human
Were protohumans able to reproduce year round, or did they have seasonal mating? How far does this trait go back on our evolutionary tree?
gpt
Well, pretty much all monkeys reproduce year round, so it's probably a reasonable bet that our most recent common ancestor with new world monkeys probably did too.  That puts us at least at 40 million years.  That said, year-round reproduction in mammals probably more a factor of climate than lineage.  If you live in the tropics (like many primates do), there aren't major seasonal variations that you could reproduce according to.