Deme M had an initial size of 4550 until 5119.0 generations ago. At that time, its population size changed to 1046, and has remained there till current time.
time_units: generations
demes:
  - name: M
    start_time: .inf
    epochs:
      - start_size: 4550
        end_time: 5119.0
      - start_size: 1046
        end_time: 0