Until a shift occurred 917.5 generations ago, deme Q's population was consistently 8614. Since then, it changed to 2922, a number that has remained unchanged to the current time.
time_units: generations
demes:
  - name: Q
    start_time: .inf
    epochs:
      - start_size: 8614
        end_time: 917.5
      - start_size: 2922
        end_time: 0