Initially, the population size of deme A stood at 1458, but this changed 4917.72 generations ago when it changed to 789, and it has been stable at that size up to today.
time_units: generations
demes:
  - name: A
    start_time: .inf
    epochs:
      - start_size: 1458
        end_time: 4917.72
      - start_size: 789
        end_time: 0