For the O deme, the population size remained at 610 until 7707.91 generations ago, at which point a exponential increase took place until 4134.0 generations for size 3737. Afterward, the population saw an exponential growth to 5225 by 371.24. From 371.24 generations ago to today, there's been a linear reduction from 5225 to 838.
time_units: generations
demes:
  - name: O
    start_time: .inf
    epochs:
      - start_size: 610
        end_time: 7707.91
      - start_size: 610
        end_size: 3737
        end_time: 4134.0
        size_function: exponential
      - start_size: 3737
        end_time: 371.24
        end_size: 5225
        size_function: exponential
      - end_time: 0
        start_size: 5225
        end_size: 838
        size_function: linear