[NiloCK]

2 and 3 seem plausibly correct to me (although 3 is a mixed bag - the hugeness increases the number of dice rolls on 1 and 2 - not only the difficulty of connecting after the fact), but what is the basis for 1?

As far as I know, we have observed complex (and extremely robust) life on every temperate, wet planet that we know about. Batting a thousand.

[ryandvm]

Life appeared on Earth almost as soon as it was possible, but it took almost 2.5 BILLION years for it to make the jump to multicellular (a.k.a. complex life). It then took another billion-plus years for life that had the slightest bit of intelligence.

The universe is probably teeming with life, but sadly, most of it is probably just goo.