Population dynamics
In neutrality test, the value of Tajima’s D and Fu’sF S of all populations and geographical groups was mainly positive, or unremarkable negative but P>0.05 (Table 5), denoting that the hypothesis of neutral evolution was not to be excluded. Mismatch distribution analyses implied that all geographical groups did not refuse to have experienced sudden expansion (P (SSD) > 0.05, P (Rag) > 0.05), except the northeast group whoseP (Rag)=0.04, slightly lower than 0.05, but also indicating a potential expansion (Table 6). Unimodal distribution curves detected in all and in each region further proved a recent demographic expansions (Figure 8). The expansion time of each groups were accessed according to the formula T =τ/2u (Rogers & Harpending, 1992; Rogers, 1995). It was estimated that the southwest group (SW) expanded first in 0.719 Mya (95% CI: 0.022-1.452), followed by the southeast group (SE) in 0.665 Mya (95% CI: 0.000-1.249), and the last northwest group (NW) in 0.586 Mya (95% CI: 0.000-0.684).