Jalpha wrote:Some minds greater than mine would argue that there has been insufficient time for life to form on earth, however sufficient time has passed for the Universe as a whole.
I don't know about that, considering the amount of mass-extinction events that have occurred already. I'd say it's rather likely that a sapient life-form could have evolved in a shorter time. Albeit, younger solar systems tend to have a higher probability of dangerous phenomena such as impacts and orbital instabilities.
The wonderful thing is that we're dealing with such astronomically huge numbers, that almost anything is possible.