Dear lord, you're evolving into a quarian. ;-) I always thought the 300-year timeframe was a bit fast because the original exiles would have brought Rannoch's germs onto the flotilla with them, but depending on what measures were necessary to prevent pandemics from spreading through whole ships over the first few generations... hm. I guess I probably have an off-kilter estimate of the resilience of the normal immune system, in both directions. (I just... never got sick at all, barring chicken pox, until after the Remodel of Doom wrecked my space-orc tendencies, and this past winter I had the same hacking cough from about October to May. :P)