qpAdm is a statistical tool for studying the ancestry of populations with histories that involve admixture between two or more source populations. I hope this tutorial helps people interested in doing own research as qpAdm validated models which are constructed well provide a high standard of evidence to the model.qpAdm is used to validate models that are fed into it by the user. The details that need to passed to the qpAdm program are as follows.
- Target population
- List of 2 or more source populations
- List of Right populations or Right Pops.
- The populations in 1 & 2 are together called Left Populations or Left Pops and the first population in this list is considered as target population by qpAdm.
- The first population among the right pops has to be a basal population (Outgroup) and usually an african population like Mbuti, ShumLaka or Mota etc is chosen for this purpose.
A standard example of a qpAdm model is
Target population (Target) = source population 1 (Source 1) + source population 2 (Source 2)
The qpAdm output will contain a p-value (also called tail probability or tailprob), admixture coefficients x & y for Source1 and Source2 respectively such that x+y = 1 (or 100%) and standard errors for those coefficients.