Deme Z had an initial size of 4494 until 8291.0 generations ago. At that time, its population size decreased to 3246, and has remained there till current time.
time_units: generations
demes:
  - name: Z
    start_time: .inf
    epochs:
      - start_size: 4494
        end_time: 8291.0
      - start_size: 3246
        end_time: 0