Population models. A) Model 1: a simple divergence model, with two sub-populations that have constant sizes (N1 and N2). Migration occur after divergence event (at time T) with rate m12 and m21; B), model 2: a divergence model with exponential growth. After the divergence time T, two sub-populations (of size N1' and N2') grow with exponential rates α1 and α2, and the population sizes at present are N1 and N2. There is no migration between the sub-populations; C) model 3: Composite model of model 1 and model 2. The same as model 2, but with migration occurring at rate m12 and m21 after divergence time.