The is, as Darren says, no scientific evidence for a soul, but consciousness causes a lot of questions for scientists and philosophers. We don’t know whether animals are conscious in the way we are (able to sit and think ‘ohh I really fancy a coke’) or whether humans are different. And we don’t really know what happens to consciousness when people die but we do know that brain activity stops and that means consciousness stops. As for ghosts, people are always trying to come up with scientific evidence that they are real. I’ve never seen any evidence that has convinced me.