Yes, if you can describe how the obelisk in 2001: A Space Odyssey works then I'd love to hear it. Basically, my view as a science fiction author is that the importance of science fiction is that you never contradict your own rules. They must be consistently applied and not be wrong according to the rules of science as known. You're writing around the laws of science as they're currently known rather than ignoring them (which is fantasy).
In the case of Ellie, overexplaining it will make it worse than better. What we have is the experts saying, "We need to dissect Ellie's brain in order to find out how this stuff works and make more of it."
The Obelisk is an example of Clarke's own Third Law, and can't really be explained with conventional means. Funny enough, "the experts" saying that you HAVE to kill Ellie is an example of Clarke's First Law in a way.
Anyway, the brain fungus thingy is a rather mundane thing and not a post-singularity invention, and it is intensely shoddy writing if you have to proclaim "don't look too closely, it'll just create more plot holes".
It's a basic bitch brain fungus. It's really easy to justify dissection with internal consistency. Hell, it adds to the whole risk/reward thing and leads to justifying Joel's decision to fuck up their shit.
"It's Science Fiction, don't question it".
What kind of a hack writer and fucking critic are you that you can even say this kind of shit with a straight face?
Fuck me I need a break from this absolute and complete stupidity.
/edit:
And to make it clear, I don't give a shit about the brain fungus or whatever, really. I'm specifically and mainly furious at this whole notion of "it's science fiction, don't question it". You're a writer. You're said before that you take more care in your own work than what you'd forgive in the writings for Fallout 3 and 4, but somehow I doubt it. Really gotta get one of your books these days, I might get an aneurysm from it and finally leave this shitty mortal coil...