All life forms are energy, energy can not be destroyed, only transformed. Once the body the dies the energy must still exist somewhere. IMO it returns to the planet from where it came, and will be recycled and used again.
Also the planet is one giant magnet with a very high percentage of iron. A video tape works by running an iron (of some form) strip across a magnet to record and play video. To me it seems possible that ghosts are merely recordings in time, an echo of what was, yet not what is, an echo that possibly will be again.
Do i believe in ghosts? Not in the supernatural sense, no. Do i believe people see/hear ghosts, i'm undecided to be honest.
But thats my view about all this reincarnation/afterlife stuff. We dont die as such, though our bodies and sense of self are linked to each other, when the body dies the individuality that was that body goes too. The energy that formed us returns to the earth to be used again.