I have done an analysis in STRUCTURE to get individual ancestry estimation in my population sample. My population is a tri-hybrid population with ancestry of European, African and Amerindian. My question is:
Since It's a tri-hybrid admixed population, do I have to include in the logistic regression model the three columns (EUR, AFR, AMR), as covariates in order to control for possible confounding effects from population stratification?
I'm asking this because I have seen people using only two (for example, EUR and AMR, or AFR and AMR)...