text: The system is a larger concept that we cannot at this point fully understand.  Think of the universe as a body, we are a small part that makes the whole function.  Just as cells in a body mature, some are created new, some are defective, all eventually die, just like we do.  Viruses evolve just like we do, they adapt because they are alive, just like us.  All things in nature adapt and change as time goes on, just as life does.  It's just one of those things we just need to accept and go on.