The soul is the DNA
The soul is a meme as old as humanity. Ancient Egyptians had that concept and had possibly inherited it from previous peoples. It figures prominently in mythologies and religions.
But ontologically (or epistemologically, I confuse the two), what is the soul? In other words, what behaviour does the soul exhibit that distinguishes it from other things in our universe (of ideas)?
The soul is a thing that inhabits a human body, that drives this body to act in a certain way, and that survives the body once the latter dies. For some, the soul can inhabit more than one body, usually one at a time. The soul is said immortal.
In a way, the same above can be said of our DNA. We hold a copy of our DNA in every cell of the body. The genes encoded in the DNA play a significant roles in our behaviour. The DNA survives us, mainly through sexual reproduction. Is DNA immortal? In other words, how old are your genes? How many future generations will they be transmitted?
So if our DNA and our so-called soul are equivalent, does that mean the mystery is solved? Far from it, we know so little about the DNA that we are likely to keep discovering new levels of function and subtlety, and maybe through that develop a "natural spirituality" that rids us of the ill-effects of superstition and supernaturalism.