Deme P maintained a population of 6497 until there was a shift 8014.185 generations ago that changed its numbers to 8241, a figure that has remained the same since.
time_units: generations
demes:
  - name: P
    start_time: .inf
    epochs:
      - start_size: 6497
        end_time: 8014.185
      - start_size: 8241
        end_time: 0