Talk:Kharaa Bacterium/@comment-34680126-20180328192833/@comment-36732798-20181023235204

Billions of Precursors were wiped. But there was never any sign of them before 4546B is discovered, despite humans colonizing the entire galaxy. So, the Precursors must have warped in from their (different) home galaxy.

They've crud resistance to Kharaa, no surprise if they never had to evolve along with it. While there's some natural resistance to work with on 4546B. Ryley also has some resistance. So it seems the disease is endemic to our galaxy, in various forms.

Likely they earlier picked Kharaa up here while exploring, took it home (oops), then came back to find a cure in creatures that long ago evolved a resistance. That included research on Earth, if the contents of their museum is anything to go by. Maybe it looked like the Black Death here (originated in Mongolia it seems)

Much prettier here on 4546B. I'm thinking the reason it glowed green is just that Precursors spliced in bioluminescent genes so they could easily track its progress in 4546B's environment.