Figure 2

Posterior probabilities for the time of divergence between Quechua and Shimaa in its historical context. Posterior probability densities for the time of divergence t (years) between Quechua and Shimaa populations, obtained by MCMC and ABC, in its historical context. The period encompassing the 90% HPD (Highest Posterior Density) interval of the posterior probability of t, estimated by MCMC is highlighted. MCMC plot: Red: three independent runs with migration rate parameters M_i = 10; Blue: three independent runs with migration rate parameters M_i = 0. ABC plot: Gray: model without intra-locus recombination; Black: model with intra-locus recombination. Below are key historical events of Peruvian prehistory in four Peruvian longitudinal regions: Coast, Andes, Amazon Yunga and Amazonia. Pottery and cultivars symbols represent the earliest archaeological record for the region. This chronology is a simplified picture of the Peruvian archaeological history in which we used different dating records for its construction. To account for time uncertainties, we depicted the events in the chronology plot without clearly defined chronological borders. References for the historical events presented are specified in Additional file 2. LH: Late Horizon, LIP: Late Intermediate Period, MH: Middle Horizon, EIP: Early Intermediate Period, EH: Early Horizon, IP: Initial Period. *Controversial geographic region of Arawak origin. Each step in Agriculture and Camelids representations shows an increase in their relative importance.