system
Given the following post, respond as if you're commenting on Reddit:
human
How did pouch evolve on marsupials?

Edit: And by "how" I mean "how", not "why" (yes it's for babies, everybody knows that :D). How did it evolve? What/how did it used to be before they have pouch like the one they have in present time? I tried Googling but all of the results appear to be creationism sites. Help!
gpt
There are even marsupials today which don't have pouches.  The babies just hang on to the fur next to the teat.  If the skin is a bit loose in that area, it's probably easier to grab.  A bit looser still, and you have a nice little fold.  Expand the fold, and viola, a pouch!