That's pretty much how I see it, too. But what keeps troubling me is the idea of heritable sinfulness. As a biologist with some knowledge of the laws of heredity (my degree is actually in Medical Genetics), I understand that unless something changes the sequence of nucleotides in the DNA, a parent cannot pass an acquired trait to his/her progeny. Meanwhile, the whole body of patristic literature, as much as I know, is very enthusiastically developing this idea that Adam's sin made the human RACE (i.e. generations next after him) sinful or prone to sin (mortal, passionate etc.), sort of like from a source of water, if you contaminate it, you get only contaminated water.
It seems to me that both you and Bogoliubtsy are leaning on biology/evolution to provide explanations or, at least, be relevant to questions that in general scientists don't claim to be able to answer or to address.
In the case of evolution vs. Adam & Eve, Evolutionary science sees a gradual development of the physical human form and its capabilities. But it doesn't address the point at which those hominids went from being animals to being human. That is, at some point, our ancestors possessed the self-awareness, language skills, and the moral sense of apes and monkeys. At some later point, they possessed the full human complement. Of course there are some radical materialists who deny there was any qualitative change to be explained/found. In that argument, there is no qualitative difference between an amoeba and a human--only a quantitative difference in complexity. But most people don't accept this even if they accept evolution--our physical forms may descend from amoebas and through monkeys but we see that at some point hominids stopped being unusually clever animals and became humans. But working from a fossil record, evolution can't identify when, where, or even how language 'started', much less self-awareness or moral nature.
So there is nothing in current evolutionary theory to conflict with the following scenario (note: I'm not arguing this scenario, simply pointing it out as one among multiple possibilities): at some point in the distant past, maybe about the time homo sapiens was differentiating from its predecessor, God chooses a mating pair of hominids and grants them a 'soul'--perhaps He does so by triggering the final set of mutions which give us a self-aware, linguisticaly capable forebrain, maybe its a separate event--this Adam and Eve are placed in a specifically designed environment. Things occur much as described in Genesis complete with an actual Fall. Afterwards, God returns the pair to the company of other hominids. Adam and Eve's own descendents intermingle with their cousins. Over time, hominids that lack that 'spark' die out and in the end only those humans who descend from Adam and Eve and possess that moral, spiritual nature are left to continue into historical times.
On the other hand, with regards, to Heorhij's comments about the 'heritability' of sinfulness: Yes, the Fathers often use the language of heredity to try to explain our Fallenness. But Orthodoxy generally understands that to be only a metaphor. Instead of thinking of it genetically, think of it in socio-economic terms. Let's say it's the ante-bellum south and my parents are slaves of Mr. X. If nothing changes, then I will be born a slave of Mr. X. But my parents manage to escape and flee to the north. Now when I'm born, I will be free man. It's not a 'genetic' thing that my parents pass on to me, but they do pass their 'state' on to me. In the same way (or in a sense in exactly the opposite way--St. Paul in fact uses the same image in reverse), Adam and Eve, when they were created (however one understands that), existed in a direct relationship to God. Through their own actions, they severed that relationship. And so when their children were born, their children were born into the same 'state' that Adam and Eve had achieved--they had no relationship to God. And that has been the 'natural' state of humanity ever since. And since God is the source of all goodness, existing in a state of separation from Him is what makes us inherently sinful. Christ offers us the opportunity to reestablish that relationship, to re-enter a state of communion with God (to sell ourselfs back to Mr. X), but that takes us farther afield.
Of course, the 'economic' model is as much a metaphor as the 'heredity' model. Any metaphor, if you try to press it too strictly, starts to show problems.