Fig. 3

Gene flow between duck populations. a Maximum likelihood tree inferred from 15 populations with ten migration edges to detect gene flow. The tree is rooted by the C. moschata populations. Populations are colored according to their geographic locations. b D-statistics to test for potential gene flow between each Chinese population (P2) and each Southeast/South Asian population (P3). We set P1 as LC (Liancheng) individuals from Fujian with fewer admixture events and O as Cairna moschata. We computed the D-statistics (((P1, P2), P3) O). Vertical bars correspond to three standard errors. Positive D values indicate gene flow between P1 and P3, whereas negative D values indicate gene flow between P2 and P3. X and Y axes represent the values of the D-statistic and P2, respectively. c Inference of the proportion of ancestral component for each donor population in the genome of each Southeast/South Asian population using Globetrotter