Similar to the gene background, the mean Tajima’s D value was less negative in drug-resistant genes from the imported group (mean =-0.45, median =-1.17) compared with that from the native group (mean =-1.6, median =-1.44) (Figure 3A), which also occurred in some other infection-related gene families, such as 2TM (mean =-0.57 and -1.05, median =-0.61 and -1.04), fikk (mean =-0.68 and -1.31, median =-0.93 and -1.52), and msp1 (mean = − -0.39 and − -1.18, median = − -0.58 and − -1.69) (Bachmann et al., 2015). This evidence concerns the gene ATAD1 and infection.