Originally, deme S had a population size of 2860, which changed to 9562 around 9940.9 generations ago and has not changed since.
time_units: generations
demes:
  - name: S
    start_time: .inf
    epochs:
      - start_size: 2860
        end_time: 9940.9
      - start_size: 9562
        end_time: 0