Initially, the population size of deme J stood at 236, but this changed 4954.2603 generations ago when it changed to 5277, and it has been stable at that size up to today.
time_units: generations
demes:
  - name: J
    start_time: .inf
    epochs:
      - start_size: 236
        end_time: 4954.2603
      - start_size: 5277
        end_time: 0