Board Thread:Warhammer 40k General Discussion/@comment-24383134-20140117210424

So I was reading Caiphas Cain for the 3rd time while in the waiting room of a doctor's office the other day and had this thought.

If a single Tyranid spore made landfall in the middle of the U.S., at exactly 12.01 EST(5:00 GMT)  tomorrow morning, how long do you predict humanity would be able to survive on Earth?

My estimate is that North and South America fall within 2-3 weeks, and the rest of the globe within 2 months. Substantially less, if the Tyranids are able to create amphibious organisms, which I'm not sure? 