Fig. 2.

Scenarios compared using the approximate Bayesian computation framework. The six scenarios include continuous gene flow following population divergence with migration varying by scenario; Scenario 1: single migration rate M_H; Scenario 2: two migration rates: one since divergence M_H and one since the whaling era M_W; or isolation following divergence, with either: Scenario 3: no subsequent gene flow; Scenario 4: gene flow at one migration rate since the whaling era M_W; Scenario 5: one migration rate since secondary contact, M_C; or Scenario 6: two migration rates: one since secondary contact, M_C, and one since the whaling era, M_W. In all scenarios, the populations diverge at time DIVERGENCE and maintain one HIST N_e until whaling, when each population declines to bottleneck population size BOT N_e during the whaling era and subsequently recover to REC N_e population size