Population structure in worldwide T. gondii isolates. The optimal K value is 4. Colors represent contributions from different ancestral haplotypes. The results of K = 3 and 5 were also depicted here. The special parameter settings are as follows: Missing data value = −9, POPID setting 1 = North America/ USA and Europe/ France, 2 = South America, 3 = East of Asia/ China, 4 = Africa/ Gabon.