题目选项分析

In California, a lack of genetic variation in the Argentine ant has allowed the species to spread widely; because they are so genetically similar to one another, the ants consider all their fellows to be close relatives and thus do not engage in the kind of fierce intercolony struggles that limit the spread of this species in its native Argentina.

In California, a lack of genetic variation in the Argentine ant has allowed the species to spread widely; because it is so genetically similar, the ant considers all its fellows to be close relatives and thus does not engage in the kind of fierce intercolony struggles that limits the spread of this species in its native Argentina.