There are far fewer alien civilizations than people would like to believe, because the road from bacteria to humans has huge gaps in it.

Well, the universe is very big, but not as many as most people would like to think is my view, because the idea that there is a trajectory going from simple cellular life like bacteria, all the way through to humans, seems to me there’s some big gaps along that way, that the eukaryotic cell, the complex cell that we have is the biggest of them.