Figure 1.

Population structure and gene flow analysis of all chicken individuals. (A) First and second principal components from a principal component analysis of all populations; (B) neighbor-joining tree for all individual chickens. (C) ADMIXTURE analysis for K = 2 up to 6. The same color indicates groups with the same ancestry. (D) Maximum likelihood tree with 3 migration events. Migration events are shown as colored arrows, shaded according to their weight. Horizontal branch lengths are proportional to the amount of genetic drift that has occurred at each branch. The scale bar shows 10 times the average standard error of the entries in the sample covariance matrix; (E) residual fit from the maximum likelihood tree in (D).