Until 7939.066 generations ago, the population of deme Q was 6457. At that point, it changed to 6283, where it has stayed up to now.
time_units: generations
demes:
  - name: Q
    start_time: .inf
    epochs:
      - start_size: 6457
        end_time: 7939.066
      - start_size: 6283
        end_time: 0