I realize the thread is supposed to only consider scientific evidence, but I'd suggest that it's hard to scientifically consider the concept of a soul without a firm definition of what is meant.

The closest thing to a rigorously-described version of the idea that I can think of comes from philosophy rather than religion (or maybe it's from the fringe between the two): substance dualism.

The linked article also includes some arguments in favor of dualism. Though I'll grant none of them are all that firmly rooted in empirical knowledge.