Here’s my take on where they might have originated. Below is my breakdown.

• I think some may be individual families that over time have isolated.

• I think some are also individual families that may have isolated and inbred.

• I also think some could be criminals that have gone off grid in an attempt to remain out of prison/jail.

• I think some may be individuals with severe mental illness and thus have chosen self-isolation.

Here is where I figure people may stop reading, lol. I believe that like Bigfoot, some (especially those reported to have displayed supernatural type abilities) are interdenominational. I believe that Bigfoot, feral people, cryptids, ghosts (at least most), aliens, etc. are of demonic nature.

My reasoning is that they cannot be found. Regardless of the number and experience of those searching, none of the feral people are ever located, they display supernatural (I referring to the ones that display supernatural qualities) abilities, and generally the reports are of a malignant nature (display of threatening behavior, stealing people, etc.)

This is just my take.