An academic paper from Cornell is claiming that life in the universe probably evolved about 9.7 billion years ago. If true, it would neatly explain why the universe seems so empty... it actually is. This argument can also be made from a philosophical angle: it took something like 99.5% of the Earth's history before intelligent life evolved. If it took that long in the wider universe (and it may very well have), then intelligent life will naturally be rare, and may not be all that much more advanced than we are.