More than likely however the smartest people in the world that have studied this their whole lives think it happened, a bunch of anomalies. Everything happened for us, but considering the size of the universe( there very likely could be a multiverse) and the educated answer of its age, there has more than likely been life on many planets over time, each species living and becoming extinct in only the blink of an eye, compared to the universes massive time line, life is a very rare thing(or so we think), but whatever can happen, will eventually happen, and the universe has had plenty of time.