Truth be told, I am reluctant to engage figures of speech on a literal level. In my mind -- as simple as it may be -- it's too easy to go from fundamental to fundamentalistic.
Nevertheless, there is a phenomenon that we in the English-speaking world refer to by the word "evil". I take it also to be of a very fundamental nature insofar as we only find it whenever and wherever members of the genus sapiens are to be found ... not always, mind you, but when it is there, humans are involved.
What one's DNA has to do with it is very unclear to me, simply because at my present state of development, I see DNA as providing a physical (as opposed to spiritual, knowing full well I am making a somewhat arbitrary distinction, but I believe useful one nevertheless) basis for whatever living creatures are. One of the things about Gebser's notion of Origin that appeals to me (and which I also find useful in my own searching) is its spiritual (as opposed to physical nature). This does not preclude the use of the notionality of "origins", for that is what I understand we are talking about here, for the most part: self, evil, etc. are non-physical, but that in and of itself does not appear to me to be enough to comprehend them. There is, for me, a "more" involved that I am comfortable with in identifying as spiritual/conscious/... and which I feel is a necessary part of the discussion. In recent decades, the work of the materialist-cognitive scientists, however, has done a lot to muddy already murky waters.
Now, I couldn't agree with you more: no division, no discernment. Or, for those of us who occasionally try to push our minds beyond our humanness, the ol' how-does-the-one-become-many problematic. In non-physical realms, if you will, this problematic is even more challenging, I think, for if we are to think about it seriously, we have to start examining those assumptions and presuppositions we normally don't even realize we have or are making. Of course, none of this lends itself to clear and definitive statements, but the beliefs that result are the tools we use to explore further. Some folks are willing to modify theirs in light of new "evidence" (however that may be conceived) and others are less willing to do so. I like to think I belong to the former group, but I have to continually check to ensure myself that I do.
(There is a great likelihood that I'm the exception not the rule when it comes to thinking fundamentally. That is neither critique nor criticism nor acclaim, it is merely an observation. When I look out into the world (well, my world, actually), I don't find a whole lot of fellow fundamentals-seekers. And that's OK, I'm not complaining, again, only observing. I would be the last to argue that we need to do away with old dualisms, regardles of how useless they may appear in my eyes (there's that damned figure of speech again!) for I know that they can be and are helpful to others. Knowing full well that some folks may never let go of them. (The devil has served a useful purpose for a lot longer than most such constructs, and new ones get introduced every day, and who knows how long how wide or how deep some of these may be usedful ...) I keep hoping nevertheless that one day I'll notice something of a shift in the direction of overcoming, but today's not the day.)
So, yes, in a sense, all metaphysics is about "ourselves", for it is only "we" (whoever or whatever that may ultimately be) who concern (or, perhaps, can concern) themselves with such matters.