The Y deme had a size of 4376 until 6205.199 generations ago. From 6205.199 generations to time 3182.858, its size reduced exponentially to 3784 individuals. After that, until 3001.4107, the population had a linear change to 4088 individuals. It then changed from 4088 to 1399, starting 3001.4107 generations ago, until current times, at a exponential rate.
time_units: generations
demes:
  - name: Y
    start_time: .inf
    epochs:
      - start_size: 4376
        end_time: 6205.199
      - start_size: 4376
        end_size: 3784
        end_time: 3182.858
        size_function: exponential
      - start_size: 3784
        end_time: 3001.4107
        end_size: 4088
        size_function: linear
      - end_time: 0
        start_size: 4088
        end_size: 1399
        size_function: exponential