I guess what I was saying was that it doesn't read as well with every sentence having the approximate same structure. If you prefer not to have the probably too large sentence in the middle like I first suggested, and I don't blame ya - I'm no writer - you might try restructuring your last compound sentence like this.
Instead of "Without complexity an organism’s evolution can only go so far; for a society that could lead to stagnation."
You might try "An organism's evolution can only go so far without complexity and for a society, that could lead to stagnation."
Or something like that. Whereever that pesky comma is supposed to go. I always have trouble with those, heh, told ya I'm no writer