FIGURE 5.

Genetic evidence of two‐step introgression to DHB. (a) Pig breeds with a higher degree of introgression were less constrained in the introgressed region. We divided the top five pig breeds with highest introgression into two groups according to their geographic location, namely JZ (JH, MS, and JQH) and HJ (GX and SZL), and calculated the average number of introgression blocks (in green) and the ratio of the introgression blocks under selection, as detected by top 5% F _st value (in red) for the two groups. (b) Observed and expected overlapped introgression blocks between GX and other large‐sized breeds. GX served as an intermediate introgression in the two‐step introgression chain. The box diagram represents the random sampling distribution from 1000 simulations; red dots indicate the number of overlapped blocks observed