Deme B maintained a population of 6430 until there was a shift 7066.81 generations ago that increased its numbers to 7488, a figure that has remained the same since.
time_units: generations
demes:
  - name: B
    start_time: .inf
    epochs:
      - start_size: 6430
        end_time: 7066.81
      - start_size: 7488
        end_time: 0