NONE.
I looked up the oldest planet and it’s 13 billion years old.
So there was time to develop very intelligent life.
I guess.
So many variables that are Incredibly Precise make life on Earth possible.
I do believe that there’s a possibility there is no other intelligent life out there.
Although who the hell knows what intelligent would mean to other specie.
Alright, my head hurts and this won’t help me pay my bills :)
fun to toss around though :)
Actually, the entire universe is only about 13-15 billion years old according to most scientific literature. We now know the incredible complexity of folding proteins such that the probability of a functional protein being created by random processes is 10 to the 164 power. That is essentially impossible and certainly couldn't occur in a mere 13 billion years.