  After a brief review of our current understanding of Miras and their
evolutionary status, three aspects of ``real-time'' evolution in these and
related stars are examined: # Chemical changes (O-rich to C-rich) due to third
dredge-up # Period changes due to the effects of the helium-shell flash # The
existence of ``fossil'' dust and gas shells. Studies of resolved gas and dust
shells are highlighted as particularly interesting. They will enable us to
examine the mass-loss histories of many late-type stars over the last ten
thousand years or so. Such observations have only recently become technically
feasible and they are expected to provide important new insights into the late
stages of stellar evolution.
