Why do scientists think viruses evolved after cells?

There's a little more to it than the previous answers indicate. It's hard to imagine a virus succeeding without a cellular host to provide for it's metabolism, etc... Yet ironically, we make the assumption that the first forms of life were self replicating nucleic acids without any cell structures.

There are two schoools of thought on the origin of viruses. One suggests that viruses degenerated from cells, becoming totally dependent on their hosts. This is definitely true for many viruses, particularly DNA viruses. The other theory suggests that viruses, in particular RNA viruses, were the first form of life.

Bottom line, we don't really know.

Why do scientists think viruses evolved after cells?ariel

because cells didn't evolve after viruses, then there would be some way of stopping viruses within the tha evolved cell

Why do scientists think viruses evolved after cells?computers

viruses cannot reproduce without 'borrowing' the capacities of cells
A virus could not reproduce without a host. It needs cells to replicate.
That is because they need the metabolism of a host cell to reproduce. Without the host cell they are just an inanimate particle.
viruses are smaller than cells.