Comment by gmuslera

One _surviving_ evolutionary form of life. And it barely survived through mass extinctions that ended the majority of the existing life during those events. For all we know the great oxigenation event could had ended any of the alternative life by then.

In any case, the existence of life, or the emergence of intelligence should not be considered a necessity. Intelligence was the way of surviving and keeping on the race for the particular conditions we had a few millions of years ago. And about life, it could be more rare than what we think, just that we are doing the question where it managed to succeed.