In general, it seems the main difference between humans and animals is that God gave us this nature so we continued to grow in a direction that is distinctive of humans.
The teachings passed down that seem restrictive and annoying to be told appear to be an attempt to avoid regression back to beasts.
In the garden there were two humans. One was taken from outside the garden, and God breathed life into clay, and then divided the genders making two though they were still one in another sense in the beginning.
Since the first two humans only had sons, then it would stand to reason they might have had children with evolved beings that looked similar that came from beasts.
So this is why it is a struggle to "be human" since there's so much animal in us.
Just a thought I had, thanks for the inspiration, maybe someone will make it into a book.